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Humans are fascinated by the bipedal locomotor capacities at both ends of the athletic spectrum—sprinting speed and endurance. Some of the more popular field (eg, soccer, rugby, and lacrosse) and court (eg, basketball, tennis, and netball) sports utilize mixed energy systems requiring an interplay of both maximal sprinting speed (MSS) and maximal aerobic speed (MAS) to meet the high-intensity running demands of varying frequency, duration, intensity, and recovery. Recently, these locomotor capacities have been considered in combination to produce what is called the anaerobic speed reserve (ASR) as part of the locomotor profile concept (MSS, MAS, and ASR). The purpose of this narrative review is to (1) provide an overview of the locomotor profile concept; (2) review the assessment methods for estimating MSS, MAS, and ASR; (3) examine the age-, sex-, and maturity-associated variations in MSS, MAS, and ASR; (4) examine the trainability of MSS, MAS, and ASR in youth athletes; and (5) conclude with the practical applications using principles of long-term athlete development for training the locomotor profile in youth field and court sport athletes. Based on the available data in young male athletes, MSS, MAS, and ASR generally increase with age and across maturity groups and are trainable. Overall, decisions on training need to consider the sport demands, current fitness and maturity status, and targeted training adaptation sought. [ABSTRACT FROM AUTHOR]

There is a lack of evidence on the additional benefits of combining caffeine (CAF) and creatine (CRE) supplementation on anaerobic power and capacity. Thus, the aim of the present study was to test the effects of combined and isolated supplementation of CAF and CRE on anaerobic power and capacity. Twenty-four healthy men performed a baseline Wingate anaerobic test and were then allocated into a CRE (n = 12) or placebo (PLA; n = 12) group. The CRE group ingested 20 g/day of CRE for 8 days, while the PLA group ingested 20 g/day of maltodextrin for the same period. On the sixth and eighth days of the loading period, both groups performed a Wingate anaerobic test 1 hr after either CAF (5 mg/kg of body mass; CRE + CAF and PLA + CAF conditions) or PLA (5 mg/kg of body mass of cellulose; CRE + PLA and PLA + PLA conditions) ingestion. After the loading period, changes in body mass were greater (p <.05) in the CRE (+0.87 ± 0.23 kg) than in the PLA group (+0.13 ± 0.27 kg). In both groups, peak power was higher (p =.01) in the CAF (1,033.4 ± 209.3 W) than in the PLA trial (1,003.3 ± 204.4 W), but mean power was not different between PLA and CAF trials (p >.05). In conclusion, CAF, but not CRE ingestion, increases anaerobic power. Conversely, neither CRE nor CAF has an effect on anaerobic capacity. [ABSTRACT FROM AUTHOR]

Purpose: We compared the adaptive responses to supramaximal high-intensity interval training (HIIT) individualized according to anaerobic speed reserve (ASR), the 30-15 Intermittent Fitness Test (VIFT), and velocity associated with maximum oxygen uptake (MAS) to determine which approach facilitates more identical adaptations across athletes with different profiles. Methods: Thirty national-level basketball players (age = 28.4 [5] y; body mass = 88.9 [6.3] kg; height = 190 [4.8] cm) were randomly assigned to 3 training groups performing 2 sets of 4, 6, 8, 6, 8, and 10-minute runs (from first to sixth week, respectively), consisting of 15-second running at Δ%20ASR (MAS + 0.2 × ASR), 95%VIFT, and 120%MAS, with 15 seconds recovery between efforts and a 3-minute relief between sets. Results: All 3 interval interventions significantly (P <.05) enhanced maximum oxygen uptake ( V ˙ O 2 max), oxygen pulse ( V ˙ O 2 / HR), first and second ventilatory threshold (VT1 and VT2), cardiac output ( Q ˙ max ), stroke volume, peak and average power output, testosterone levels, and testosterone-to-cortisol ratio following the training period. Different values of interindividual variability (coefficient of variation) for the percentage changes of the measured variables were observed in response to HIITASR, HIITvIFT, and HIITMAS for V ˙ O 2 max (8.7%, 18.8%, 34.6%, respectively), V ˙ O 2 / HR (9.5%, 15.0%, 28.6%), VT1 (9.6%, 19.6%, 34.6%), VT2 (21.8%, 32.4%, 56.7%), Q ˙ max (8.2%, 16.9%, 28.8%), stroke volume (7.9%, 15.2%, 23.5%), peak power output (20%, 22%, 37.3%), average power output (21.1%, 21.3%, 32.5%), testosterone (52.9%, 61.6%, 59.9%), and testosterone-to-cortisol ratio (55.1%, 59.5%, 57.8%). Conclusions: Supramaximal HIIT performed at Δ%20ASR resulted in more uniform physiological adaptations than HIIT interventions prescribed using VIFT or MAS. Although hormonal changes do not follow this approach, all the approaches induced an anabolic effect. [ABSTRACT FROM AUTHOR]

Purpose: This study examined performance and physiological adaptations following 3 weeks of repeated-sprint training (RST) with blood-flow restriction (BFR) or without (non-BFR). Methods: Twenty-six semiprofessional and amateur adult male team-sport players were assessed for repeated-sprint ability, anaerobic capacity, leg lean mass, neuromuscular function, and maximal aerobic capacity before and after RST. Participants completed 9 cycling RST sessions (3 sets of 5–7 × 5-s sprints, 25-s passive recovery, 3-min rest) over a 3-week period with BFR or non-BFR. Results: During RST sessions, the BFR group demonstrated lower mean power output compared with non-BFR (−14.5%; g = 1.48; P =.001). Significant improvements (P <.05) in mean and peak power output during repeated-sprint ability (+4.1%; g = 0.42, and + 2.2%; g = 0.25, respectively) and anaerobic capacity (+4.8%; g = 0.47, and + 4.7%; g = 0.32, respectively) tests, leg lean mass (+2.0%; g = 0.16), and peak aerobic power (+3.3%; g = 0.25) were observed from pretesting to posttesting without any between-groups differences. No significant changes (P >.05) were observed for maximal isometric voluntary contraction and maximal aerobic capacity. Peak rate of force development decreased (P =.003) in both groups following RST (−14.6%; g = 0.65), without any between-groups differences. Conclusions: Repeated-sprint ability, anaerobic capacity, leg lean mass, and peak aerobic power improved following 3 weeks of RST; however, the addition of BFR did not further enhance adaptations. Interestingly, comparable improvements were achieved between groups despite lower external loads experienced during RST sessions with BFR. [ABSTRACT FROM AUTHOR]

Objectives: To analyze the positional distances covered above generic and individualized speed thresholds within the most demanding phases of match play. Categorized by position, 17 English Premier League players' match data were analyzed over 2 consecutive seasons (2019–20 and 2020–21). The most demanding phases of play were determined using a rolling average across 4 periods of 1, 3, 5, and 10 minutes. Distance covered in the time above the standard speed of 5.5 m/s was analyzed, with individualized metrics based on the maximal aerobic speed (MAS) test data. Results: Central defenders displayed lower values for high-intensity periods when compared with fullbacks, midfielders, and wide midfielders for both generic and individualized metrics. MAS during 1-minute periods was significantly higher for forwards when compared with central defenders (82.9 [18.9] vs 67.5 [14.8] for maximum high-speed running [HSR] and 96.0 [15.9] vs 75.7 [13.8] HSR for maximum MAS activity). The maximum effect size differences between the central midfielders, wide midfielders, and fullbacks for HSR and MAS measures under the maximum HSR criterion was 0.28 and 0.18 for the 1-minute period, 0.36 and 0.19 for the 3-minute period, 0.46 and 0.31 for the 5-minute period, and 0.49 and 0.315 for the 10-minute period. Conclusions: Individualized speed metrics may provide a more precise and comparable measure than generic values. Data appear to be consistent across playing positions except for central defenders. This information may allow practitioners to directly compare individualized physical outputs of non–central defenders during the most demanding phases of play regardless of the players' positional group. This may provide coaches with important information regarding session design, training load, and fatigue monitoring. [ABSTRACT FROM AUTHOR]

This article comments on a recent study about high-intensity interval training (HIIT) and its methodological problems. The authors agree with the study's identification of issues in research on the affective responses to HIIT but argue that the study's guidance on quantifying exercise intensity during HIIT is flawed. They propose using a percentage of peak workload during an incremental test as a more appropriate measure of exercise intensity. The authors also criticize the use of heart rate as a measure of intensity during interval exercise and suggest using metabolic landmarks instead. They provide examples from other studies to support their argument. Additionally, they refute criticisms regarding the appropriateness of HIIT intensities in studies comparing affective and enjoyment responses. [Extracted from the article]

Purpose: Short-track speed skating race distances of 500, 1000, and 1500 m that last ∼40 seconds to ∼2.5 minutes and require a maximal intensity at speeds beyond maximal oxygen uptake (VO2max). Recently, the anaerobic speed reserve (ASR) has been applied by scientists and coaches in middle-distance sports to deepen understanding of 1- to 5-minute event performance where different physiological profiles (speed, hybrid, and endurance) can have success. Methods: World-class (women, n = 2; men, n = 3) and international-level (women, n = 4; men, n = 5) short-track speed skaters completed maximal aerobic speed and maximal skating speed tests. ASR characteristics were compared between profiles and associated with on-ice performance. Results: World-class athletes raced at a lower %ASR in the 1000- (3.1%; large; almost certainly) and 1500-m (1.8%; large; possibly) events than international athletes. Men's and women's speed profiles operated at a higher %ASR in the 500-m than hybrid and endurance profiles, whereas in the 1500-m, endurance profiles worked at a substantially lower %ASR than hybrid and speed profiles. Women's 500-m performance is very largely associated with maximal skating speed, while women's maximal aerobic speed appears to be a key determining factor in the 1000- and 1500-m performance. Conclusion: World-class short-track speed skaters can be developed in speed, hybrid, and endurance profiles but achieve their performance differently by leveraging their strongest characteristics. These results show nuanced differences between men's and women's 500-, 1000- and 1500-m event performance across ASR profile that unlock new insights for individualizing athlete performance in these disciplines. [ABSTRACT FROM AUTHOR]

Purpose: This study investigated within- and between-matches blood lactate (La−) responses across an international Rugby Sevens tournament (5 matches over 2 d) in male and female players. Methods: Earlobe blood samples were taken from 25 professional players around matches: before warm-up (PRE), immediately upon finishing match participation (POST), and 30 minutes postmatch (30 min). Results: POST [La−] (mean [SD], range) for males was 10.3 (3.2; 2.9–20.2) mmol·L−1 and for females was 9.1 (2.3; 3.4–14.6) mmol·L−1. Linear mixed-effects models revealed a decrease in POST [La−] after match 5, compared to match 1. Increased PRE [La−] was found before match 2 (+0.8 [0.6–1.1] mmol·L−1), match 3 (+0.8 [0.5–1.1] mmol·L−1), and match 5 (+0.6 [0.4–0.9] mmol·L−1) compared to match 1 (all P <.001). The [La−] remained elevated at 30 min, compared to PRE (+1.7 [1.4–2.0] mmol·L−1, P <.001), with ∼20% of values persisting >4 mmol·L−1. Higher POST was observed in males compared to females (+1.6 [0.1–3.2] mmol·L−1, P =.042); however, no differences between sexes were found across 30 min or PRE [La−]. No [La−] differences between positions (backs and forwards) were identified. Conclusions: Lactate concentrations above 10 mmol·L−1 are required to effectively simulate the anaerobic demands of international Rugby Sevens matches. Practitioners are advised to individualize anaerobic training prescription due to the substantial variability observed within positional groups. Additionally, improving athletes' metabolic recovery capacity through training, nutrition, and recovery interventions may enhance physical preparation for subsequent matches within a day, where incomplete lactate clearance was observed. [ABSTRACT FROM AUTHOR]

The study aimed to establish the test-retest reliability of detrended fluctuation analysis of heart rate variability (DFA-α1) based exercise intensity thresholds, assess its agreement with ventilatory- and lactate-derived thresholds and the moderating effect of sex and cardiorespiratory fitness (CRF) on the agreement. Intensity thresholds for thirty-seven participants (17 females) based on blood lactate (LT1/LT2), gas-exchange (VT1/VT2) and DFA-α1 (αTh1/αTh2) were assessed. Heart rate (HR) at αTh1 and αTh2 showed good test-retest reliability (coefficient of variation [CV] < 6%), and moderate to high agreement with LTs (r = 0.40 – 0.57) and VTs (r = 0.61 – 0.66) respectively. Mixed effects models indicated bias magnitude depended on CRF, with DFA-α1 overestimating thresholds versus VTs for lower fitness levels (speed at VT1 <8.5 km⋅hr−1), while underestimating for higher fitness levels (speed at VT2 >15 km⋅hr−1; VO2max >55 mL·kg−1·min−1). Controlling for CRF, sex significantly affected bias magnitude only at first threshold, with males having higher mean bias (+2.41 bpm) than females (−1.26 bpm). DFA-α1 thresholds are practical and reliable intensity measures, however it is unclear if they accurately represent LTs/VTs from the observed limits of agreement and unexplained variance. To optimise DFA-α1 threshold estimation across different populations, bias should be corrected based on sex and CRF. [ABSTRACT FROM AUTHOR]

Purpose: This study compared the effects of polarized running training adapted to the menstrual cycle (MC) phases versus polarized training adapted contrary to the MC on endurance performance and cardiovascular parameters. Methods: Thirty-three naturally menstruating, moderately trained females (age: 26 ± 4 years; BMI: 22.3 ± 3.2 kg/m2; V ˙ O2max/rel: 40.35 ± 4.61 ml/min/kg) were randomly assigned to a control (CON) and intervention (INT) group. Both groups participated in a load-matched eight-week running training intervention. In the INT, high-intensity sessions were aligned with the mid and late follicular phase, low-intensity sessions with the early and mid-luteal phase, and recovery with the late luteal and early follicular phase. In the CON, high-intensity sessions were matched to the late luteal and early follicular phase, and recovery to the mid and late follicular phase. Endurance performance and cardiovascular parameters were assessed at baseline and after the intervention. Results: Twenty-six females completed the intervention. A repeated measures ANOVA determined no time × group interaction effect for any parameter. A significant time effect was found for maximal oxygen uptake (F(1,12) = 18.753, p = 0.005, ηp2 = 0.630), the velocity at the ventilatory threshold one (F(1,12) = 10.704, p = 0.007, ηp2 = 0.493) and two (F(1,12) = 7.746, p =.018, ηp2 =.413). Conclusion: The training intervention improved endurance performance in both groups, with no further benefit observed from the MC-adapted polarized training in a group-based analysis. Replications with an extended intervention period, a larger sample size, and a more reliable MC determination are warranted. [ABSTRACT FROM AUTHOR]

Purpose: This study investigated whether a running-adapted version of the cycling-based "step–ramp–step" (SRS) protocol would improve prediction of V ˙ O2 in treadmill exercise compared to the traditional prescriptive approach. Methods: Fourteen healthy individuals (6 females; 25 ± 6 years; 66.1 ± 12.7 kg) performed a treadmill-based SRS protocol including a ramp-incremental test to task failure followed by two constant-speed bouts within the moderate-(MODstep—below estimated lactate threshold; θLT), and heavy-intensity domains (HVYstep—between θLT and respiratory compensation point; RCP). Using the uncorrected V ˙ O2-to-speed relationship from the ramp exercise, three constant-speed bouts were performed at 40–50% between: baseline and θLT (CSEMOD); θLT and RCP (CSEHVY); and RCP and peak (CSESEV). For CSEMOD, CSEHVY, and CSESEV measured end-exercise V ˙ O2 was compared to predicted V ˙ O2 based on the: (i) "SRS-corrected" V ˙ O2-to-speed relationship (where MODstep and HVYstep were used to adjust the V ˙ O2 relative to speed); and (ii) linear "uncorrected" data. Results: Average treadmill speeds for CSEMOD and CSEHVY were 7.8 ± 0.8 and 11.0 ± 1.4 km·h−1, respectively, eliciting end-exercise V ˙ O2 of 1979 ± 390 and 2574 ± 540 mL·min−1. End-exercise V ˙ O2 values were not different compared to SRS-predicted V ˙ O2 at CSEMOD (mean difference: 5 ± 166 mL·min−1; p = 0.912) and CSEHVY (20 ± 128 mL·min−1; p = 0.568). The linear "uncorrected" estimates were not different for CSEMOD (− 91 ± 172 mL·min−1; p = 0.068) but lower for CSEHVY (− 195 ± 146 mL·min−1; p < 0.001). For CSESEV (running speed: 13.8 ± 1.7 km·h−1), the end-exercise V ˙ O2 was not different from peak V ˙ O2 achieved during the ramp (3027 ± 682 vs. 2979 ± 655 mL·min−1; p = 0.231). Conclusion: In healthy individuals, the SRS protocol more accurately predicts speeds for a target V ˙ O2 compared to traditional approaches. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the agreement between the two Gas Exchange Thresholds (GETs = GET1 and GET2), identified by the conventional V-Slope method, and two Respiratory Frequency Thresholds (fRTs = fRT1 and fRT2) obtained from a novel, low-cost, and simple method of breakpoint determination. Methods: Fifty middle-aged males (age: 50–58 years; V ˙ o2peak: 37.5 ± 8.6 mL·Kg−1·min−1), either healthy or with chronic illnesses, underwent an incremental cycle exercise test to determine maximal oxygen uptake ( V ˙ o2max/ V ˙ o2peak), GETs and fRTs. Results: There were no statistical differences [P > 0.05; ES: 0.17 to 0.32, small] between absolute and relative (56–60% V ˙ o2peak) oxygen uptake ( V ˙ o2) values at GET1 with those obtained at fRT1, nor between V ˙ o2 values at GET2 with those at fRT2 (76–78% V ˙ o2peak). Heart rate (HR) at fRT1, and V ˙ o2 and HR at fRT2 showed very large correlations (r = 0.75–0.82; P < 0.001) and acceptable precision (SEE < 7–9%) in determination of their corresponding values at GET1 and GET2. The precision in the estimation of V ˙ o2 at GET1 from fRT1 was moderate (SEE = 15%), while those of power output at GET1 (SEE = 23%) and GET2 (SEE = 12%) from their corresponding fRTs values were very poor to moderate. Conclusion: HR at fRT1 and V ˙ o2 and HR at fRT2, determined using a new objective and portable approach, may potentially serve as viable predictors of their respective GETs. This method may offer a simplified, cost-effective, and field-based approach for determining exercise threshold intensities during graded exercise. [ABSTRACT FROM AUTHOR]

Introduction: Running economy (RE) deteriorates during prolonged running, although the effect of measuring energy cost (EC) or oxygen cost (OC) on the magnitude of these changes has not been investigated. Similarly, it is unknown if runners’ performance level may influence the deterioration of RE during prolonged running. The aims of this study were to compare changes in EC and OC measurements of RE during a prolonged run in a large cohort of well-trained male runners, and to compare changes between runners of high- and low-performance standard. Methods: Forty-four male runners (maximal oxygen uptake (V̇O2max) 62.4 mL·kg-1 ·min-1 ; 10-km time: 35:50 ± 4:40 mm:ss) completed an incremental test determining lactate threshold 1 (LT1) and V̇O2max, and on a separate occasion, a 90-min run at LT1. Respiratory gases were collected at 15-min intervals. Subsequently, subgroups of high- (HP; 10-km time: 31:20 ± 01:00 mm:ss) and low-performing (LP; 10-km time: 41:50 ± 01:20 mm:ss) runners were compared. Results: RE deterioration was only fractionally larger when expressed as OC than EC (0.1% greater from 30-90 min; P < 0.001), perhaps due to the small change in respiratory exchange ratio (-0.01) in this study. For the HP group, increases were lower than LP after 90 min in both EC (+2.3% vs +4.3%; P < 0.01) and OC (+2.4% vs +4.5%; P < 0.01). Similarly, at standardized distances, changes were lower for HP versus LP, for example, at 16.7 km + 1.0 versus +3.2% for EC (P < 0.01), and +1.2 vs +3.4% for OC (P < 0.001). Conclusions: The deterioration of RE was dependent on athlete’s performance level, with HP runners displaying superior RE durability. The use of EC or OC had only a fractional influence on RE durability, although this may gain importance with larger shifts in substrate metabolism. [ABSTRACT FROM AUTHOR]

Purpose: This study reports the results of a 20-yr (2005 to 2024) follow-up study of two 2-time Olympic and 6-time world champion rowing athletes. To provide a comprehensive picture of adaptations in physiological and performance characteristics to long-term training, we monitored the athletes’ physiological and performance data annually through five 4-yr developmental phases. Methods: Maximal oxygen uptake ( V̇O2max), maximal minute power (MMP), and power output corresponding to anaerobic threshold (PAT) were derived from a rampwise exercise test on a rowing ergometer. In addition, average power output sustained during all-out tests over 2000 and 6000 m on a rowing ergometer was also obtained. Results: V̇O2max peaked at age 22 for athlete A and at age 25 for athlete B (at ~7 L·min-1 ) before stabilizing and then gradually declining to a range of 6.2 to 6.5 L·min-1 for both athletes. MMP stabilized in both rowers at values between 550 and 575 W and displayed minimal fluctuations over the final two phases of the study. In addition, MMP closely resembled the corresponding average power output sustained during the 2000-m all-out tests on a rowing ergometer. Average power output during 2000 and 6000-m all-out tests showed steady improvements over the monitored phases of the study, with the highest power output crew averages for both 2000-m (532 W; 5 min 48 s) and 6000-m (463 W; 18 min 4 s) tests recorded during the last 4-yr phase of the assessment. Conclusions: Improvements in rowing ergometer performance over 2000 and 6000 m appear to be largely independent of the multiyear changes in V̇O2max. Long-term rowing training resulted in continuous improvements in MMP and PAT throughout the monitored phases, which more closely mimicked improvements in rowing ergometer performance. [ABSTRACT FROM AUTHOR]

Context Ghrelin circulates in acylated (AG) and deacylated (DAG) forms, which are known to affect appetite. Although acute exercise has been shown to modulate ghrelin levels, data on the impact of exercise intensity on AG and DAG levels and their effects on appetite are sparse and primarily limited to males. Objective To investigate the effect of exercise intensity and sex on ghrelin levels and appetite in untrained humans. Methods Eight males (age: 43.1 ± 10.9 years; body mass index [BMI]: 22.2 ± 1.7 kg/m2; peak oxygen consumption [VO2peak]: 36.3 ± 6.4 mL/kg/min) and 6 females (age: 32.2 ± 11.1 years; BMI: 22.7 ± 1.0 kg/m2; VO2peak: 29.2 ± 4.0 mL/kg/min) completed a maximal graded cycle ergometer lactate threshold (LT)/VO2peak test. These data were used to determine the exercise intensity on 3 subsequent randomized control or calorically matched cycle exercise bouts: (1) CON, no exercise; (2) MOD, the power output at LT; (3) HIGH, the power output associated with 75% of the difference between LT and VO2peak. Perception of appetite was analyzed using visual analog scales. Results Females had higher levels of total ghrelin (TG) (P =.03) and DAG (P =.01) at baseline than males. Both groups exhibited reduced DAG levels in HIGH compared with MOD and CON (P <.0001-.004); however, only females had significantly reduced AG in HIGH (P <.0001). Hunger scores were higher in MOD than in CON (P <.01). Conclusion High-intensity may be superior to moderate-intensity exercise for reducing ghrelin levels and modifying hunger, and sex may impact this response. [ABSTRACT FROM AUTHOR]

Cardiac rehabilitation is crucial for the secondary prevention of cardiovascular disease, the leading cause of death worldwide. In Japan, as hospitalization periods have been shortened due to advances in medical technology and government policies, outpatient rehabilitation focused on lifestyle and physical activity (PA) is becoming increasingly important as hospital stays shorten. This study was aimed to identify patient characteristics that define the different types of PA and sedentary behaviors, and patient factors in 92 Japanese outpatients by using accelerometers. The patients were found to spend considerable time being sedentary (663.7 ± 118.1 min/day) and very little time engaging in moderate-to-vigorous PA (MVPA, 25.6 (10.6–43.4) min/day). Regression analysis revealed that the daily duration of sedentary behavior was 64 min longer in men than in women (β = 64.2, 95% CI[12.9, 115], p = 0.015); furthermore, men engaged in 22% less light PA (β = -0.245, 95% CI[-0.388, -0.102], p = 0.001). Additionally, MVPA increased by 43% for every 1 metabolic equivalent (MET) task increase in the anaerobic threshold (AT) (β = 0.367, 95% CI[0.035, 0.698], p = 0.031) but decreased by 3% per year of age(β = -0.035, 95% CI[-0.056, -0.015], p < 0.001). The study also found that body mass index (BMI) was negatively correlated with walking time (β = -0.039, 95% CI[-0.075, -0.003], p = 0.036), while AT was positively correlated with MVPA (β = 0.367, 95% CI[0.035, 0.698], p = 0.031) but negatively correlated with time above the AT (β = -2.06, 95% CI[-2.53, -1.59], p < 0.001). These results emphasize the importance of customizing rehabilitation programs according to sex, age, BMI, and AT differences. Furthermore, monitoring home activities and providing individualized prescriptions may enhance the effectiveness of rehabilitation programs. [ABSTRACT FROM AUTHOR]

Above the first lactate threshold, the steady‐state V̇O2${{\dot{V}}_{{{{\mathrm{O}}}_{\mathrm{2}}}}}$ is delayed or prevented due to the V̇O2${{\dot{V}}_{{{{\mathrm{O}}}_{\mathrm{2}}}}}$ slow component (V̇O2SC${{\dot{V}}_{{{{\mathrm{O}}}_{\mathrm{2}}}{\mathrm{SC}}}}$). This phenomenon has been associated with muscle fatigue, but evidence for a causal relationship is equivocal. Moreover, little is known about the contribution of pedalling technique adjustments to V̇O2SC${{\dot{V}}_{{{{\mathrm{O}}}_{\mathrm{2}}}{\mathrm{SC}}}}$ during fatiguing cycling exercise. Eleven participants completed constant power trials at 10% above the second lactate threshold. Muscle fatigue was assessed, utilizing femoral nerve stimulation and instrumented pedals, while V̇O2${{\dot{V}}_{{{{\mathrm{O}}}_{\mathrm{2}}}}}$, quadriceps oxygenation, electromyography (EMG) and pedal force components were measured. Correlations between physiological and mechanical variables were estimated at group and individual levels. Group correlations revealed moderate values for V̇O2SC${{\dot{V}}_{{{{\mathrm{O}}}_{\mathrm{2}}}{\mathrm{SC}}}}$ with quadriceps twitch force (r = −0.51) and muscle oxygenation (r = −0.52), while weak correlations were observed for EMG amplitude (r = 0.26) and EMG mean power frequency (r = −0.16), and with pedalling mechanical variables such as peak total downstroke force (r = −0.16), minimum total upstroke force (r = −0.16) and upstroke index of effectiveness (r = 0.16). The findings here align with prior literature reporting significant correlations between the magnitude of muscle fatigue and that of V̇O2SC${{\dot{V}}_{{{{\mathrm{O}}}_{\mathrm{2}}}{\mathrm{SC}}}}$, although there was large interindividual variability for all the reported correlations. Considering the heterogeneity in the data, it is difficult to determine the relative impact of pedalling technique adjustments on V̇O2SC${{\dot{V}}_{{{{\mathrm{O}}}_{\mathrm{2}}}{\mathrm{SC}}}}$ overall, but the present study opens the possibility that in some cases, increases in V̇O2${{\dot{V}}_{{{{\mathrm{O}}}_{\mathrm{2}}}}}$ secondary to technical adjustments may be ‘superimposed’ on the underlying V̇O2SC${{\dot{V}}_{{{{\mathrm{O}}}_{\mathrm{2}}}{\mathrm{SC}}}}$. [ABSTRACT FROM AUTHOR]

Objective To compare the effects of two exercise intensities on metabolic syndrome (MS). Methods Forty-nine MS patients hospitalized in Taiyuan Central Hospital from December, 2022 to January 2024 were selected and randomly divided into two groups : a standard group (n = 24) and individual group (n = 25). All patients underwent cardiopulmonary exercise test ( CPET) before and after treatment, collecting major indexes including body parameter, body component, and metabolic indicator for prescribing exercise programs. The standard group was trained with exercise intensity prescribed on heart rate reserve, while the individual group received the exercise with intensity prescribed on ventilatory threshold. Both groups received equal energy consumption exercise intervention with the same exercise frequency for 12 weeks. Results The two groups demonstrated significant improvements in waist circumference (WC), body mass index (BMI), body fat related indexes, and systolic blood pressure after intervention (P < 0.05). The individual group showed significant improvements inWC, BMI and body fat related indexes as compared to the standard group (P < 0.05). Both groups showed significant improvements in peak oxygen uptake, (PeakVO2), peak load power (Peak WR), peak metabolic equivalent (PeakMets), and peak respiratory exchange ratio ( Peak RER ) after intervention (P < 0.05 ). The individual group presented significant improvements in peak heart rate (HRpeak), peak oxygen pulse (Peak VO2/HR), and maximum voluntary ventilation (MVV) (P < 0.05) after intervention. Before intervention, the standard group demonstrated significantly higher levels in PeakVO2 and Peak MET compared to the individual group (P < 0.05), but after intervention the two groups showed no significant differences in the two indexes. After the intervention, the individual group demonstrated insignificant improvements in all indexes compared to the standard group (P > 0.05). Conclusions Both exercise prescriptions based on CPET can effectively improve the health-related indicators of MS patients on condition of moderate exercise intensity. However, the program prescribed based on individualized ventilatory threshold shows superiority to the program prescribed based on maximum physiological value in improving these indicators. [ABSTRACT FROM AUTHOR]

Background: Determining thresholds by measuring blood lactate levels (lactate thresholds) or gas exchange (ventilatory thresholds) that delineate the different exercise intensity domains is crucial for training prescription. This systematic review with meta-analyses aims to assess the overall validity of the first and second heart rate variability - derived threshold (HRVT1 and HRVT2, respectively) by computing global effect sizes for agreement and correlation between HRVTs and reference – lactate and ventilatory (LT-VTs) – thresholds. Furthermore, this review aims to assess the impact of subjects' characteristics, HRV methods, and study protocols on the agreement and correlation between LT-VTs and HRVTs. Methods: Systematic computerised searches for studies determining HRVTs during incremental exercise in humans were conducted. The agreements and correlations meta-analyses were conducted using a random-effect model. Causes of heterogeneity were explored by subgroup analysis and meta-regression with subjects' characteristics, incremental exercise protocols, and HRV methods variables. The methodological quality was assessed using QUADAS-2 and STARDHRV tools. The risk of bias was assessed by funnel plots, fail-safe N test, Egger's test of the intercept, and the Begg and Mazumdar rank correlation test. Results: Fifty included studies (1160 subjects) assessed 314 agreements (95 for HRVT1, 219 for HRVT2) and 246 correlations (82 for HRVT1, 164 for HRVT2) between LT-VTs and HRVTs. The standardized mean differences were trivial between HRVT1 and LT1-VT1 (SMD = 0.08, 95% CI -0.04–0.19, n = 22) and between HRVT2 and LT2-VT2 (SMD = -0.06, 95% CI -0.15–0.03, n = 42). The correlations were very strong between HRVT1 and LT1-VT1 (r = 0.85, 95% CI 0.75–0.91, n = 22), and between HRVT2 and LT2-VT2 (r = 0.85, 95% CI 0.80–0.89, n = 41). Moreover, subjects' characteristics, type of ergometer, or initial and incremental workload had no impact on HRVTs determination. Conclusion: HRVTs showed trivial differences and very strong correlations with LT-VTs and might thus serve as surrogates. These results emphasize the usefulness of HRVTs as promising, accessible, and cost-effective means for exercise and clinical prescription purposes. Key Points: HRV-derived thresholds (HRVT1 and HRVT2) showed trivial standardised mean differences and very strong correlations with their respective reference thresholds (lactate and ventilatory). Subjects' characteristics, ergometer, or initial and incremental workload did not impact HRVTs determination. HRVT2 is accurately determined by frequency-domain and non-linear HRV indices, and by using short increments during graded exercise tests. [ABSTRACT FROM AUTHOR]

This study compared cardiovascular and metabolic responses during concentric and eccentric stepping. Eight participants (5 m, 3f; 22 ± 2 years) performed maximal concentric and eccentric ramp incremental tests on a modified stepping ergometer. Subsequently, three randomized 15‐min constant‐power tests were performed (1) concentric stepping at 90% of the concentric lactate threshold (LT), (2) eccentric stepping at the same power, and (3) eccentric stepping at the same oxygen uptake (V̇O2). At equivalent power (36 ± 6 W, p = 0.62), eccentric stepping resulted in 46 ± 8% lower V̇O2, 16 ± 6% lower heart rate (HR), and 11 ± 5% lower mean arterial blood pressure compared to concentric (p < 0.01). Matching V̇O2 required 65 ± 19% more power during eccentric stepping (p < 0.01). During this test, eccentric V̇O2 and HR continued to increase, resulting in a 22 ± 29% higher V̇O2 and 19 ± 16% higher HR in the final minute (p < 0.001). Reduced cardiorespiratory demand during eccentric stepping at the same power as concentric demonstrates a higher eccentric power is required to produce the same V̇O2. However, despite being below the concentric LT, eccentric V̇O2 and HR continued to increase past the predicted steady state, indicating a higher exercise intensity. [ABSTRACT FROM AUTHOR]

Purpose: Moderate-intensity aerobic exercise is safe and beneficial in atrial fibrillation (AF) and coronary heart disease (CHD). Irregular or rapid heart rates (HR) in AF and other heart conditions create a challenge to using HR to monitor exercise intensity. The purpose of this study was to assess the potential of breathing frequency (BF) to monitor exercise intensity in people with AF and CHD without AF. Methods: This observational study included 30 AF participants (19 Male, 70.7 ± 8.7 yrs) and 67 non-AF CHD participants (38 Male, 56.9 ± 11.4 yrs). All performed an incremental maximal exercise test with pulmonary gas exchange. Results: Peak aerobic power in AF ( V ˙ O2peak; 17.8 ± 5.0 ml.kg−1.min−1) was lower than in CHD (26.7 ml.kg−1.min−1) (p <.001). BF responses in AF and CHD were similar (BF peak: AF 34.6 ± 5.4 and CHD 36.5 ± 5.0 breaths.min−1; p =.106); at the 1st ventilatory threshold (BF@VT-1: AF 23.2 ± 4.6; CHD 22.4 ± 4.6 breaths.min−1; p =.240). % V ˙ O2peak at VT-1 were similar in AF and CHD (AF: 59%; CHD: 57%; p =.656). Conclusion: With the use of wearable technologies on the rise, that now include BF, this first study provides an encouraging potential for BF to be used in AF and CHD. As the supporting data are based on incremental ramp protocol results, further research is required to assess BF validity to manage exercise intensity during longer bouts of exercise. [ABSTRACT FROM AUTHOR]

From a physiological perspective, the delineation between steady-state and non-steady-state exercise, also referred to as the maximal metabolic steady state, holds paramount importance for evaluating athletic performance and designing and monitoring training programs. The critical power and the maximal lactate steady state are two widely used indices to estimate this threshold, yet previous studies consistently reported significant discrepancies between their associated power outputs. These findings have fueled the debate regarding the interchangeability of critical power and the maximal lactate steady state in practice. This paper reviews the methodological intricacies intrinsic to the determination of these thresholds, and elucidates how inappropriate determination methods and methodological inconsistencies between studies have contributed to the documented differences in the literature. Through a critical examination of relevant literature and by integration of our laboratory data, we demonstrate that differences between critical power and the maximal lactate steady state may be reconciled to only a few Watts when applying appropriate and strict determination criteria, so that both indices may be used to estimate the maximal metabolic steady-state threshold in practice. To this end, we have defined a set of good practice guidelines to assist scientists and coaches in obtaining the most valid critical power and maximal lactate steady state estimates. [ABSTRACT FROM AUTHOR]

We investigated the influence of anaerobic speed reserve (ASR) on post-activation performance enhancement (PAPE). Twenty-two endurance runners and triathletes were evaluated for maximum sprinting speed (MSS) and countermovement jump (CMJ) before (non-fatigued) and after (fatigued) an incremental running test. They were allocated in LASR (low-ASR) and HASR (high-ASR) groups for comparisons between conditions. HASR showed greater CMJ and MSS (both p ≤ 0.005) performances, with enhanced CMJ in fatigued condition (p ≤ 0.008). Significant correlations were found between ASR, CMJ, and MSS in both conditions (p ≤ 0.01) for the entire sample, and between ∆CMJ and ∆MSS (p ≤ 0.001) in LASR. Our results show that ASR profile influences PAPE. [ABSTRACT FROM AUTHOR]

Purpose: To examine the feasibility and effects of a functional high-intensity exercise intervention performed in a group-setting on functionality, cardiovascular health and physical performance in adolescents with cerebral palsy (CP). Methods: Ten adolescents with a diagnosis of CP (2 females; 16.6 ± 3.4 years; GMFCS: I-II) participated in a 12-week training intervention, containing progressive resistance training using free weights and high-intensity workouts twice a week. The six-minute walking test, arterial stiffness and physical performance (strength and power tests) were measured before and after the intervention. Results: No adverse events were reported. We measured small increases in the six-minute walking test (Δ = 28.8 m, 95% CI [-1.78;52.7]; g = 0.34 [-0.04;0.72]) and a small reduction in arterial stiffness (Δ = −4.65% [-10.90;1.25]; g = −0.46 [-1.36;0.21]). All measures of physical performance increased (0.24 ≤ g ≤ 0.88). Conclusion: Functional training with free weights in high-functioning adolescents with CP is safe and effective in increasing parameters of physical performance and cardiovascular health. Positively influenced indicators of everyday independence (i.e. strength parameters) showed a transfer into movements of daily life. Concerns about adverse events through high-intensity training in adolescents with CP appear unjustified when training is performed progressively, following basic training principles. Implications for Rehabilitation: High-intensity functional exercise in a group-setting is safe in high functioning adolescents with cerebral palsy (CP) when following basic training principles. Compound, multi-joint movements performed at high intensities show a transfer-effect into daily functionality. High-intensity resistance training combined with anaerobic and aerobic exercise should be included in standard therapy for high-functioning adolescents with CP. The group-setting shows potential as innovative strategy for long-term training effectiveness. [ABSTRACT FROM AUTHOR]

After Fontan operation, decreased venous capacitance and venoconstriction are adaptive mechanisms to maintain venous return and cardiac output. The consequent higher venous pressure may adversely impact end-organ function, exercise capacity and result in worse clinical outcomes. This pilot study evaluated the safety and effect of isosorbide dinitrate (ISDN), a venodilator, on exercise capacity, peripheral venous pressure (PVP), and liver stiffness in patients with Fontan circulation. In this prospective single-arm trial, 15 individuals with Fontan circulation were evaluated at baseline and after 4 weeks of therapeutic treatment with ISDN. Primary aims were to assess the safety of ISDN and the effect on maximal exercise. We also aimed to evaluate the effect of ISDN on ultrasound-assessed liver stiffness, markers of submaximal exercise, and PVP at rest and peak exercise. Repeated measures t-tests were used to assess change in variables of interest in response to ISDN. Mean age was 23.5 ± 9.2 years (range 11.2–39.0 years), and 10/15 (67%) were male. There was no statistically significant change in peak VO2 (1401 ± 428 to 1428 ± 436 mL/min, p = 0.128), but VO2 at the anaerobic threshold increased (1087 ± 313 to 1115 ± 302 mL/min, p = 0.03). ISDN was also associated with a lower peak exercise PVP (22.5 ± 4.5 to 20.6 ± 3.0 mmHg, p = 0.015). Liver stiffness was lower with ISDN, though the difference was not statistically significant (2.3 ± 0.4 to 2.1 ± 0.5 m/s, p = 0.079). Of the patients completing the trial, mild headache was common (67%), but there were no major adverse events. Treatment with ISDN for 4 weeks is well-tolerated in patients with a Fontan circulation. ISDN is associated with an increase in VO2 at anaerobic threshold, lower peak PVP, and a trend toward lower liver stiffness. Larger, longer duration studies will be necessary to define the impact of ISDN on clinical outcomes in the Fontan circulation. Clinical Trial Registration: URL: https://clinicaltrials.gov. Unique identifier: NCT04297241. [ABSTRACT FROM AUTHOR]

Objectives: This study investigated the efficacy of wheat peptide supplementation compared to regular proteins in elite cross-country skiers, providing insights into the metabolic and performance effects of these supplements in order to guide athletes in selecting optimal energy sources for training and competition. Methods: Nineteen healthy male cross-country skiers were enrolled and assigned to either the peptide group (PEP, n = 9) or the protein group (PRO, n = 10). A four-week intervention study involving supplementation with wheat peptides/regular proteins was conducted, and pre- and post-intervention assessments were performed to evaluate exercise capacity and metabolic profiles. Results: The study found that the PEP group and the PRO group showed distinct within-group effects on exercise performance. The PEP group demonstrated improved aerobic capacity, including better performance in 10 km roller skating, an increased lactate threshold, and reduced resting blood lactate levels. The PRO group enhanced anaerobic capacity, such as improved sprint time, hexagon test performance, and lactate clearance. Metabolomic analysis revealed specific metabolic pathways affected in each group, with the PEP group showing impacts on the α-linolenic acid pathway and the PRO group on ketone body synthesis and degradation as well as vitamin B6 metabolism. Conclusions: Our findings indicate that wheat oligopeptides and regular proteins have comparable effects on exercise performance. However, the wheat peptides may offer greater advantages in enhancing aerobic capacity. No significant variations were observed in blood metabolite profiles between the two groups, but distinct metabolic pathways exhibited different responses. [ABSTRACT FROM AUTHOR]

The aim of the study was to assess the influence of year-long training of race walkers on physiological cost and total energy center of mass (CoM). The assessment performed was based on indicating the differences between the resulting energy cost in a group of elite race walkers walking at technical, threshold, and racing speeds calculated by physiological and biomechanical methods before beginning and after finishing a year-long training cycle. The study involved 12 competitive race walkers who had achieved champion or international champion level. Their aerobic endurance was determined by means of a direct method, applying an incremental exercise test on the treadmill. The gait of the participants was recorded using the 3D Vicon analysis system. Changes in mechanical energy amounted to the value of the total external work of the muscles needed to accelerate and lift the center of mass during a normalized gait cycle. The highest influence on the total external work increase for increasing speeds of gait in both examinations was attributed to the changes in the kinetic energy resulting from the center of mass movement. A statistically significant decrease of the mean value of total external work for racing speed was observed in the second examination (p < 0.001). An approx. 8% decrease (NS) of EE energy cost, standardized by body mass and distance covered, was found between the first and second examinations. The energy cost and total external work were significantly differentiated by the walkers' gait speeds (p < 0.05–0.001). The energy cost significantly differed from the total external work at p < 0.001. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the applicability of the Lactate Threshold (LT) to predict maximal oxygen uptake (˙VO2max) and demarcate the boundary between the moderate- to heavy- intensity domain (HRm-h) in old age in comparison to the most utilized methods. A cross-sectional validation study was conducted. Participants aged 61 to 77 performed a familiarization procedure, an incremental maximal exercise treadmill test (CPX) for ˙VO2max determination, the Six-minute Walk Test (6MWT), and a discontinuous incremental field test for LT determination. Lower (P<0.01) internal effort was required for LT testing (76±8%HRmax) compared to 6MWT (92±9%HRmax). The application of the 6MWT reference equations overestimated ˙VO2max by 10–23%. LTs better estimated the ˙VO2max (r ≈0.90, SEE: ≈3.0] compared to the 6MWT (r=0.68, SEE=5.5). HRm-h determined by the CPX differed (20%; P=0.001) from that obtained by LT. HRm-h stratification indicated participants fall into the very light to the vigorous intensity domains. LT testing is more submaximal than the 6MWT, and is a valuable tool to estimate the ˙VO2max in older male adults. Implementation of LT testing in physical activity programs might help improving the quality of aerobic exercise training in older men. [ABSTRACT FROM AUTHOR]

Motocross is one of the most popular high-speed motorcycle races, which takes place on a naturally closed track with significant challenges. This study aimed to characterize anthropometric, circulatory, and lower and upper limb muscle properties based on laboratory and race-recorded characteristics. Male competitors (n = 3) aged 14 years (MX) were included in the study. All three boys have national and international experience. Metabolic characteristics (ventilation, oxygen consumption, and carbon dioxide production) and heart rate (HR) were measured in the laboratory while HR and speed were measured while racing. No significant difference was found between the three competitors in terms of HR during the race. In terms of number of sprints (No. sprint) and maximum speed (Speedmax), we found the most successful runner (highest finisher) to have the most sprints and maximum speed. Comparing the metabolic characteristics, it was found that racing was between the respiratory breakpoint (VT1) and the respiratory compensation point (RCP), but, in several cases, crossed the anaerobic threshold. While motocross riders are exposed to extreme conditions and high physical demands, in motorsport, victories depend not only on the athlete's physical abilities but also on several factors such as driving technique, mental effort, equipment efficiency and resistance, race strategy, and team competence. [ABSTRACT FROM AUTHOR]

Cervical or upper-thoracic spinal cord injury (SCI, ≥T6) often leads to low resting blood pressure (BP) and impaired cardiovascular responses to acute exercise due to disrupted supraspinal sympathetic drive. Epidural spinal cord stimulation (invasive, ESCS) and transcutaneous spinal cord stimulation (noninvasive, TSCS) have previously been used to target dormant sympathetic circuits and modulate cardiovascular responses. This case series compared the effects of cardiovascular-optimised ESCS and TSCS versus sham ESCS and TSCS on modulating cardiovascular responses and improving submaximal upperbody exercise performance in individuals with SCI. Seven males with a chronic, motor-complete SCI between C6 and T4 underwent a mapping session to identify cardiovascular responses to spinal cord stimulation. Subsequently, four participants (two ESCS and two TSCS) completed submaximal exercise testing. Stimulation parameters (waveform, frequency, intensity, epidural electrode array configuration, and transcutaneous electrode locations in the lumbosacral region) were optimised to elevate cardiovascular responses (CV-SCS). A sham condition (SHAM-SCS) served as a comparison. Participants performed armcrank exercise to exhaustion at a fixed workload corresponding to above ventilatory threshold, on separate days, with CV-SCS or SHAM-SCS. At rest, CVSCS increased BP and predicted left ventricular cardiac contractility and total peripheral resistance. During exercise, CV-SCS increased time to exhaustion and peak oxygen pulse (a surrogate for stroke volume), relative to SHAM-SCS. Ratings of perceived exertion also tended to be lower with CV-SCS than SHAM-SCS. Comparable improvements in time to exhaustion with ESCS and TSCS suggest that both approaches could be promising ergogenic aids to support exercise performance or rehabilitation, along with reducing fatigue during activities of daily living in individuals with SCI. [ABSTRACT FROM AUTHOR]

Aim: While Baduanjin, a traditional Chinese mind‐body exercise, has shown potential health benefits, its efficacy in improving outcomes for heart failure patients with mildly reduced or preserved ejection fraction (HFmrEF/HFpEF) has not been well documented. We aimed to investigate the adjunctive impact of Baduanjin on exercise capacity and quality of life for HFmrEF/HFpEF. Methods: Patients with HFmrEF/HFpEF were enrolled in this multicenter randomized clinical trial. All participants were randomized to conventional cardiac rehabilitation with or without an additional 12‐week Baduanjin exercise. The primary endpoint was the distance covered in a 6‐min walk test (6MWD), while key secondary outcomes included quality of life measured by the Minnesota Living with Heart Failure Questionnaire (MLHFQ) and cardiopulmonary function including anaerobic threshold (VO2 AT). Results: A total of 120 patients were enrolled, and 109 completed all session and tests. The mean age of the 120 patients was 60.5 years (SD, 9.21 years), and 23 (19.2%) were women. The Baduanjin group exhibited a 6.14% improvement in 6MWD compared to a 1.32% improvement in the control group (median improvement, 25.0 vs. 5.0 m; p < 0.001) at 12th week. The VO2 AT increased by 25.87% in the Baduanjin group versus 3.94% in the control group (p < 0.001). Quality of life also significantly improved in the Baduanjin group as indicated by MLHFQ score changes (–16.8% vs. –3.99%; p < 0.001). Conclusions: Adding Baduanjin to exercise‐based cardiac rehabilitation for patients with ischemic HFmrEF or HFpEF are generally safe and could provide significant improvements in exercise capacity and quality of life. [ABSTRACT FROM AUTHOR]

Technique-specific high-intensity interval training (HIITTS) has been proven to be an effective method to enhance the sport-specific bio-motor abilities of taekwondo athletes. However, studies regarding its effects on comprehensive measures of cardiorespiratory fitness are limited. Furthermore, there is a lack of clarity regarding the extent of individual adaptations to this method compared to HIIT in the form of repeated sprints (HIITRS). This study compared the individual adaptations to HIITRS and HIITTS on cardiorespiratory fitness and anaerobic power in trained taekwondo athletes (age = 19.8 ± 1.3 years; body mass = 75.4 ± 9.1 kg; height = 1.73 ± 0.0 .m). All participants completed three sessions per week of a 60-minute regular taekwondo training. Following the 60-minute training, participants completed 3 sets of 10 x 4 s all-out HIITRS or same sets of repeated kicks with both legs (HIITTS) over a 6-week training period. In both groups, rest intervals were set at 15 seconds between efforts and one minute between sets. Before and after the training period, participants underwent a series of lab- and field-based tests to evaluate cardiorespiratory fitness and bio-motor abilities. Both interventions resulted in significant improvements in maximum oxygen uptake (VO2max), O2 pulse (VO2/HR), first ventilatory threshold (VT1), second ventilatory threshold (VT2), cardiac output (Qmax), stroke volume (SV), peak power output (PPO), average power output (APO), squat jump (SJ), and countermovement jump (CMJ). However, linear speed (20-m speed time) and taekwondo-specific agility test (TSAT) only responded to HIITRS. HIITRS resulted in greater changes in VO2max, VO2/HR, VT2, and Qmax, and higher percentage of responders in measured parameters than HIITTS. In addition, HIITRS elicited lower inter-individual variability (CV) in percent changes from pre- to post-training in all measured variables. These results suggest that incorporating 3 sessions per week of HIITRS into regular taekwondo training results in significantly greater and more homogenized adaptations in cardiorespiratory fitness and bio-motor abilities than HIITTS among trained taekwondo athletes. [ABSTRACT FROM AUTHOR]

Despite the well-documented benefits of sprint interval training (SIT) and plyometric training (PT) in improving the physical fitness of soccer players, it remains unclear which of these training methods is superior for enhancing players' aerobic and anaerobic performance. Therefore, this study aimed to compare the effects of SIT and PT on physical performance measures of male soccer players. Thirty male soccer players were randomly assigned to PT (n = 10), SIT (n = 10), and an active control group (CON, n = 10). Before and after the training period, participants underwent a battery of tests consisting of vertical jump, Wingate, linear sprint with and without ball dribbling, change of direction, ball kick, and the Yo-Yo intermittent recovery level 1 (Yo-Yo IR1) tests. Both groups exhibited similar improvements in maximal kicking distance (PT, effect size [ES] = 0.68; SIT, ES = 0.92) and measures of aerobic fitness including maximum oxygen uptake (PT, ES = 1.24; SIT, ES = 1.26) and first (PT, ES = 0.85; SIT, ES = 1.08) and second (PT, ES = 0.86; SIT, ES = 0.98) ventilatory thresholds. However, PT intervention resulted in greater changes in vertical jump (ES = 1.72 vs. 0.82, p = 0.001), anaerobic power (peak power, ES = 1.62 vs. 0.97, p = 0.009; mean power, ES = 1.15 vs. 1.20, p = 0.05), linear speed (20-m, ES = -1.58 vs. -0.98, p = 0.038; 20-m with ball, ES = -0.93 vs. 0.71, p = 0.038), and change of direction ability (ES = -2.56 vs. -2.71, p = 0.046) than SIT. In conclusion, both PT and SIT demonstrated effectiveness in enhancing aerobic performance among male soccer players. However, PT yielded superior improvements in anaerobic power, vertical jump, linear speed, and change of direction performance compared to SIT. These findings suggest that PT may offer additional benefits beyond aerobic conditioning. [ABSTRACT FROM AUTHOR]

Competitive collegiate dance combines elements of gymnastics and acrobatics with more traditional styles, such as ballet, jazz, and modern dance. Assessing the physiological demands and identifying clear measures of intensity and duration of such dance provide a framework for planning the competitive season and developing strength and conditioning programs. This study examined the blood lactate (BL), heart rate (HR), and ratings of perceived exertion (RPE) of 14 well-trained female dancers on a competitive collegiate dance team. Subjects completed a treadmill test to determine their lactate threshold (LT) and then performed a 120-second choreographed jazz dance routine in cumulative 30-second segments, during which physiological markers were measured. All subjects exceeded their individually determined LT values by 90 seconds into the dance routine. A moderate (rs = 0.53; p < 0.001) positive correlation was observed between HR and RPE, as was a strong (rs = 0.70; p < 0.001) positive correlation between BL and RPE. Subjects worked at or above LT for much of the 120-second jazz dance routine, indicating that competitive collegiate dance is physiologically demanding and highly anaerobic. Understanding the physiological demands of competitive collegiate dance allows strength and conditioning professionals to develop, monitor, and adjust training parameters, which will aid in minimizing injury and maximizing competitive performance in collegiate dancers. [ABSTRACT FROM AUTHOR]

Objective: The main objective of this study was to compare lactate thresholds and aerobic capacity from a graded-intensity exercise test (GXT) for near-infrared spectroscopy measurements in healthy, untrained individuals and highly trained athletes. Methods: This study included 29 untrained students (13 females) and 27 highly trained speed skaters (13 females). A maximal effort GXT was performed on a cycloergometer. The lactate-based aerobic and anaerobic thresholds, and the corresponding thresholds for muscle oxygen saturation (SmO2), were determined. Results: The power values determined for all thresholds were significantly higher in female and male speed skaters compared to male and female college students. SmO2 at anaerobic thresholds was significantly lower in female speed skaters than in female students. Both female and male skaters showed greater changes in SmO2 after the GXT compared to students. The recovery did not significantly differ between groups within gender. There was a significant positive correlation in females between the rate of muscle reoxygenation and VO2max power (r = 0.610). In speed skaters, the rate of muscle reoxygenation was not significantly higher than students and correlated positively with VO2max (r = 0.449). Conclusions: The SmO2 at the exercise thresholds, during and after maximal exercise, depends on the training status of the individual. The participants with a higher physical fitness level showed greater decreases in ΔSmO2 at the AT level, as well as after maximal exercise. SmO2 corresponding to the well-established exercise thresholds may be applied to guide training prescription. The rate of muscle reoxygenation after a GXT was also dependent on the aerobic capacity of the participants. [ABSTRACT FROM AUTHOR]

Detailed heart rate (HR) response patterns during exercise in patients with heart failure (HF) and sinus rhythm remain uncertain. We screened consecutive patients with HF who underwent cardiopulmonary exercise tests at a large academic center from November 2013 to July 2023. HR response during exercise was statistically classified using logistic differential equation models. A total of 99 patients were included. Of them, 75 patients were assigned to "sigmoidal pattern" and the other 24 to "exponential pattern." Patients with the sigmoidal pattern were older and exhibited higher plasma B-type natriuretic peptide levels. Increases in HR and oxygen consumption (V̇ o 2)/kg up to the anaerobic threshold level were not different between both patterns. However, beyond the threshold, the sigmoidal pattern group showed no further increase in HR and significantly lower V̇ o 2/kg than their counterparts (interactions for P < 0.001). HR response during exercise in patients with heart failure and sinus rhythm was categorized into two unique groups: sigmoidal and exponential patterns. More detailed clarification of the sigmoidal pattern, potentially indicating sinus node dysfunction, should offer new clinical insights for chronotropic incompetence. NEW & NOTEWORTHY: Heart rate response patterns can be classified into two groups among patients with chronic heart failure reaching maximal exertion: sigmoidal and exponential. [ABSTRACT FROM AUTHOR]

Since assessing aerobic capacity is key to enhancing swimming performance, a simple and widely applicable technology should be developed. Therefore, we aimed to noninvasively visualize real‐time changes in sweat lactate (sLA) levels during swimming and investigate the relationship between lactate thresholds in sweat (sLT) and blood (bLT). This prospective study included 24 university swimmers (age: 20.7 s ± 1.8 years, 58% male) who underwent exercise tests at incremental speeds with or without breaks in a swimming flume to measure heart rate (HR), bLT, and sLT based on sLA levels using a waterproof wearable lactate sensor attached to the dorsal upper arm on two different days. The correlation coefficient and Bland–Altman methods were used to verify the similarities of the sLT with bLT and personal performance. In all tests, dynamic changes in sLA levels were continuously measured and projected onto the wearable device without delay, artifacts, or contamination. Following an initial minimal current response, with increasing speed the sLA levels increased substantially, coinciding with a continuous rise in HR. The speed at sLT strongly correlated with that at bLT (p < 0.01 and r = 0.824). The Bland–Altman plot showed a strong agreement (mean difference: 0.08 ± 0.1 m/s). This prospective study achieved real‐time sLA monitoring during swimming, even with vigorous movement. The sLT closely approximated bLT; both were subsequently validated for their relevance to performance. Highlights: A new technique using a wearable device can measure sweat lactate (sLA) levels during swimming without artifacts or contamination.Lactate threshold assessed using sLA dynamics is consistent with that calculated from blood samples.The current novel measurement method is expected to promote a personalized training regimen and simultaneous multi‐person measurements. [ABSTRACT FROM AUTHOR]

Purpose: Heart rate (HR) response is likely to vary in people with Parkinson's disease (PD), particularly for those with chronotropic incompetence (CI). This study explores the impact of CI on HR and metabolic responses during cardiopulmonary exercise test (CPET) in people with PD, and its implications for exercise intensity prescription. Methods: Twenty-eight participants with mild PD and seventeen healthy controls underwent CPET to identify the presence or absence of CI. HR and metabolic responses were measured at submaximal (first (VT1) and second (VT2) ventilatory thresholds), and at peak exercise. Main outcome measures were HR, oxygen consumption (VO2), and changes in HR responses (HR/WR slope) to an increase in exercise demand. Results: CI was present in 13 (46%) PD participants (PDCI), who during CPET, exhibited blunted HR responses compared to controls and PD non-CI beyond 60% of maximal workload (p ≤ 0.05). PDCI presented a significantly lower HR at VT2, and peak exercise compared to PD non-CI and controls (p ≤ 0.001). VO2 was significantly lower in PDCI than PD non-CI and controls at VT2 (p = 0.003 and p = 0.036, respectively) and at peak exercise (p = 0.001 and p = 0.023, respectively). Conclusion: Although poorly understood, the presence of CI in PD and its effect on HR and metabolic responses during incremental exercise is significant and important to consider when programming aerobic exercises. [ABSTRACT FROM AUTHOR]

Ischemic preconditioning (IPC) appears to improve exercise performance although there is uncertainty about the intensity dependence of this effect. The present study sought to clarify effects of IPC on physiological responses at and below peak oxygen uptake, including the gas exchange threshold (GET). Ten male and female participants completed five cycling ramp tests (10 W/min) to failure, with the final two tests preceded by either IPC (4 × 5 min 220 mmHg bilateral leg occlusions) or SHAM (20 mmHg), in a randomised crossover design. The rates of O2 uptake ( V ˙ O2), carbon dioxide output ( V ˙ CO2), and expired ventilation ( V ˙ E) were measured at rest and throughout exercise. Exercise data were fitted using several functions to identify GET, two ventilatory thresholds and peak V ˙ O2. IPC increased V ˙ O2 at GET by ~ 9% (IPC: 1.89 ± 0.51 L/min, SHAM: 1.73 ± 0.56 L/min; p = 0.055) and power output at GET by ~ 11% (IPC: 133 ± 36 W, SHAM: 120 ± 39 W; p = 0.022). In addition, peak power output increased by 2.4% following IPC (IPC: 217 ± 50 W, SHAM: 212 ± 51 W; p = 0.052), but there was no significant effect of IPC on peak V ˙ O2 (IPC: 2.87 ± 0.68 L/min, SHAM: 2.84 ± 0.73 L/min; p = 0.60) or the ventilatory thresholds. The present results suggest that IPC improves GET and peak power output but not peak V ˙ O2 during a maximal graded test. [ABSTRACT FROM AUTHOR]

Post‐exercise hot (HWI) and cold (CWI) water immersion are popular strategies used by athletes in a range of sporting contexts, such as enhancing recovery or adaptation. However, prolonged heating bouts increase neuroendocrine responses that are associated with perceptions of fatigue. Fourteen endurance‐trained runners performed three trials consisting of two 45‐min runs at 95% lactate threshold on a treadmill separated by 6 h of recovery. Following the first run, participants completed one of HWI (30 min, 40°C), CWI (15 min, 14°C) or control (CON, 30 min rest in ambient conditions) in a randomised order. Perceived effort and recovery were measured using ratings of perceived exertion (RPE) and the Acute Recovery and Stress Scale (ARSS), whilst physiological responses including venous concentrations of a range of neuroendocrine markers, superficial femoral blood flow, heart rate and rectal temperature were measured. Exercise increased neuroendocrine responses of interleukin‐6, adrenaline and noradrenaline (all P < 0.001). Additionally, perceptions of overall recovery (P < 0.001), mental performance capacity (P = 0.02), physical performance capability (P = 0.01) and emotional balance (P = 0.03) were reduced prior to the second run. However, there was no effect of condition on these variables (P > 0.05), nor RPE (P = 0.68), despite differences in rectal temperature, superficial femoral blood flow following the first run, and participants' expected recovery prior to the intervention (all P < 0.001). Therefore, athletes may engage in post‐exercise hot or cold‐water immersion without negatively impacting moderate‐intensity training sessions performed later the same day. What is the central question of this study?Does post‐exercise heating or cooling alter recovery and perception of effort during subsequent exercise?What is the main finding and its importance?Neither post‐exercise heating nor post‐exercise cooling altered perceived recovery or perception of effort during subsequent exercise, despite heating inducing large increases in blood flow to the lower limbs. Contrary to our hypotheses, neither heating nor cooling had any impact on inflammatory or neuroendocrine responses in plasma. Post‐exercise heating does not appear to exacerbate fatigue as previously suggested in other studies. [ABSTRACT FROM AUTHOR]

To synthesize evidence about physical fitness levels in children with developmental coordination disorder (DCD) compared with typically developing (TD) children. We searched four databases (PubMed, Scopus, Web of Science, and PsycINFO) for cross-sectional, case-control, and cohort studies comparing physical fitness between children with and without DCD. We assessed the methodological quality of the studies with the Newcastle-Ottawa Scale (NOS). We calculated Cohen's d effect sizes to provide clinical evidence of group differences in aerobic capacity, anaerobic capacity, muscle strength, body composition and flexibility. We included 32 studies for qualitative synthesis after applying eligibility criteria. All selected studies ranged from moderate to high research quality. Effect sizes in favor of typically developing children over children with DCD were large for aerobic capacity (d = 1.15), anaerobic capacity (d = 0.90), and muscle strength (d = 0.79), and small for body composition (d = 0.43) and flexibility (d = 0.21) outcomes. Children with DCD presented significantly lower physical fitness than their typically developing peers, particularly in aerobic and anaerobic capacity and in muscle strength. [ABSTRACT FROM AUTHOR]

Background: Nordic walking (NW) is a physical sports activity that has been sufficiently studied from the point of view of health, but physiological and performance analyses have not been so much. Objectives: With this study, we intend to analyse the physical work areas, according to ventilatory thresholds, that occur during a NW competition. Methods: Four participants of different characteristics anthropometrics (weight 57.6–85.6 kg; height 165.8–178 cm; and fat percentage 14.5–21.5%) gender (3 males and 1 female) and age (15–57 years) who participated in the NW regional championship have been chosen, and their electrocardiographic tracing was recorded using a NUUBO® device throughout the race, obtaining average and maximum heart rates (HR) in eight sections of the circuit. Previously, in the laboratory, a maximal stress test was performed to determine the maximum oxygen consumption (VO2max), the first (VT1) and second (VT2) ventilatory threshold (VT). With these data, four work areas were obtained. Results: Most of the sections of the circuit were conducted with average HRs in zone 2a (above average between VT1 and VT2 but below VT2) and peak HRs in zone 3 (between VT2 and VO2max). Conclusions: We conclude that, with the data collected on HR, VO2max, and VT, the training zones obtained can be related to the heart rates in the different sections of the circuit. This can be used to improve the sports performance of the walkers. [ABSTRACT FROM AUTHOR]

Understanding the differences in ventilatory responses during exercise between patients with fibromyalgia and those with other chronic pain disorders is crucial for developing effective therapeutic interventions, especially in exercise to identify the better physical therapy prescription. Both populations face unique challenges that impact their ability to engage in physical activity; yet, the underlying physiological responses can vary significantly. In this context, the methodology of this study entailed conducting a comparative analysis of the ventilatory response during exercise in patients with fibromyalgia and those with other chronic pain disorders. The experimental protocol included a total of 31 participants (n = 13 diagnosed with fibromyalgia and n = 18 diagnosed with other chronic pain conditions). All participants completed a stress test, where the ventilatory parameters were measured in three stages (i.e., resting, incremental exercise, and recovery). The results revealed significant differences ( p < 0.05 ) in ventilatory responses between both groups. Patients with fibromyalgia exhibited reduced time for the aerobic threshold and a higher respiratory frequency in the anaerobic threshold compared to those with other chronic pain disorders. Furthermore, fibromyalgia patients demonstrated higher values in the ventilatory coefficient during the test and in the recovery stage. In conclusion, these differences underscore the need for tailored exercise programs that specifically address the unique ventilatory challenges faced by fibromyalgia patients to improve their physical function and overall quality of life. [ABSTRACT FROM AUTHOR]

Copyright of Retos: Nuevas Perspectivas de Educación Física, Deporte y Recreación is the property of Federacion Espanola de Asociaciones de Docentes de Educacion Fisica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Retos: Nuevas Perspectivas de Educación Física, Deporte y Recreación is the property of Federacion Espanola de Asociaciones de Docentes de Educacion Fisica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Retos: Nuevas Perspectivas de Educación Física, Deporte y Recreación is the property of Federacion Espanola de Asociaciones de Docentes de Educacion Fisica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Retos: Nuevas Perspectivas de Educación Física, Deporte y Recreación is the property of Federacion Espanola de Asociaciones de Docentes de Educacion Fisica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Retos: Nuevas Perspectivas de Educación Física, Deporte y Recreación is the property of Federacion Espanola de Asociaciones de Docentes de Educacion Fisica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)