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Altered movement complexity, indicative of system dysfunction, has been demonstrated with increased running velocity and neuromuscular fatigue. The critical velocity (CV) denotes a metabolic and neuromuscular fatigue threshold. It remains unclear whether changes to complexity during running are coupled with the exercise intensity domain in which it is performed. The purpose of this study was to examine whether movement variability and complexity differ exclusively above the CV intensity during running. Ten endurance-trained participants ran at 95%, 100%, 105% and 115% CV for 20 min or to task failure, whichever occurred first. Movement at the hip, knee, and ankle were sampled throughout using 3D motion analysis. Complexity of kinematics in the first and last 30 s were quantified using sample entropy (SampEn) and detrended fluctuation analysis (DFA-α). Variability was determined using standard deviation (SD). SampEn decreased during all trials in knee flexion/extension and it increased in hip internal/external rotation, whilst DFA-α increased in knee internal/external rotation. SD of ankle plantar/dorsiflexion and inversion/eversion, knee internal/external rotation, and hip flexion/extension and abduction/adduction increased during trials. Hip flexion/extension SampEn values were lowest below CV. DFA-α was lower at higher velocities compared to velocities below CV in ankle plantar/dorsiflexion, hip flexion/extension, hip adduction/abduction, hip internal/external rotation. In hip flexion/extension SD was highest at 115% CV. Changes to kinematic complexity over time are consistent between heavy and severe intensity domains. The findings suggest running above CV results in increased movement complexity and variability, particularly at the hip, during treadmill running.

Introduction Microcurrent has been used to promote tissue healing after injury or to hasten muscle remodeling post exercise post exercise. Purpose To compare the effects of resistance training in combination with either, microcurrent or sham treatment, on-body composition and muscular architecture. Additionally, changes in performance and perceived delayed onset muscle soreness (DOMS) were determined. Methods Eighteen males (25.7 ± 7.6 years) completed an 8-week resistance training program involving 3 workouts per week (24 total sessions) wearing a microcurrent (MIC, n = 9) or a sham (SH, n = 9) device for 3-h post-workout or in the morning during non-training days. Measurements were conducted at pre and post intervention. Results Compared to baseline, both groups increased (p p p p = 0.045) than that observed in SH. Furthermore, only MIC enlarged (p p p p Conclusion A 3-h daily use of microcurrent maximized muscular architectural changes and attenuated DOMS with no added significant benefits on body composition and performance.

As life expectancy in people living with HIV (PWH) has increased, the focus of management has shifted to preventing and treating chronic illnesses. Regular physical activity (PA) has been shown to reduce the impact of HIV on both physical and mental health. Our objectives were to assess the PA levels of PWH compared to HIV negative controls; investigate factors associated with PA; and determine the effect of PA levels on quality of life and mental well-being. We recruited 110 PWH and 110 HIV negative controls in this cross-sectional, single-centre study. Physical activity, quality of life and mental well-being were assessed using the rapid assessment of physical activity tool, EQ-5D-5L Questionnaire, and the Warwick-Edinburgh Mental Well-being Score. Binary logistic regression and multiple linear regression were used to identify factors associated with PA levels and mental well-being scores respectively. PWH were less likely to meet the WHO-recommended PA requirements compared to controls (50.0% vs. 64.5%; p = 0.041) and had significantly lower mental wellbeing and quality of life scores. Additionally, in PWH higher PA levels were associated with improved self-rated quality of life scores (p = 0.027). Our results suggest that targeted exercise programmes could have a beneficial effect on health status in PWH.

Karsten, DB, Fu, Y, Larumbe-Zabala, DE, Seijo, DM, and Naclerio, DF. Impact of two high-volume set configuration workouts on resistance training outcomes in recreationally trained men. J Strength Cond Res 35(2S): S136-S143, 2021-This study compared the effects of 2 weekly equalized by volume, loading zone and frequency resistance training designs using repetition to failure (RTF) or not to failure (NTF), on body composition, strength, and mechanical power. Based on individual baseline maximal strength, 18 recreationally resistance-trained men were pair-matched and consequently randomly assigned to an RTF (n = 9) or an NTF (n = 9) protocol. Subjects trained for 6 weeks using 2 different routines performed once per week (2 workouts per week). The RTF protocol comprised 4 sets of 10 repetitions per exercise with 2-minute rest and the NTF involved 8 sets of 5 repetitions per exercise with 1-minute rest. Subjects were tested pre- and post-intervention for maximal strength, upper- and lower-body power, fat-free mass, limb circumferences, and muscle thickness. Compared to baseline, both groups improved (p0.01) the maximal loads lifted in the bench press (RTF +9.44 ± 3.00 kg; NTF +7.22 ± 4.41 kg) and the squat (RTF +9.44 ± 4.64 kg; NTF +11.1 ± 10.33 kg) exercises, but only the NTF group increased (p0.05) upper-body power (+15.73 ± 12.59 W). Conversely, only the RTF group showed significant (p0.05) increase of the elbow flexors (+3.44 ± 5.11 mm) and vastus medialis (+3.28 ± 2.32 mm) thickness, whereas both groups enhanced anterior deltoid thickness (RTF +1.84 ± 1.68 mm, p0.05; NTF +2.76 ± 2.63 mm, p0.01). Although both training strategies improved strength, the RTF group elicited superior hypertrophic outcomes, whereas the NTF protocol resulted in more favorable improvements for upper-body power.

PURPOSE This study aimed to assess and compare the systemic response of oxygen uptake kinetics and muscle deoxygenation between a 30-min rest protocol and a multivisit protocol on the parameters of the power-duration relationship (i.e., critical power [CP] and W'). METHODS Nine endurance-trained triathletes reported to the laboratory on five occasions: a preliminary graded exercise test and a familiarization, a 30-min single-visit protocol (time trials of 10, 5, and 2 min in that order interspersed with 30 min rest), and a multivisit protocol (time trials of 10, 5, and 2 min in randomized order interspersed by >24 h rest). Heart rate (HR) was recorded continuously, respiratory gases were measured breath by breath, and deoxygenation was recorded at 10 Hz using near-infrared spectroscopy (NIRS) during all tests. Blood lactate (BLa-) concentration was measured before all time trials. Maximal HR (HRmax), oxygen uptake (V˙O2) during the first 2 min (V˙O2onset), mean response time, end-exercise V˙O2 (V˙O2peak), V˙O2 amplitude (amplV˙O2), O2 deficit, NIRS τ, amplitude (amplNIRS), and time delay were assessed. To compare the two protocols and to assess the differences in W' and CP, a paired sample t-test was used as well as a two-way ANOVA to assess the differences between trials and/or protocols, including trial-protocol interactions. RESULTS No significant differences, and trivial effect sizes, were found for W' and CP between protocols (P = 0.106-0.114, d < 0.01-0.08). Furthermore, no significant differences between protocols were found for all parameters, except for [BLa-]. Significant differences between trials were found for V˙O2ampl, V˙O2onset, NIRS τ, amplNIRS, [BLa-], and HRmax. CONCLUSION Results suggest that W' and CP can be determined using the 30-min rest protocol without confounding effects of previous severe exercise compared with the multivisit protocol.

Post-exercise microcurrent based treatments have shown to optimise exercise-induced adaptations in athletes. We compared the effects of endurance training in combination with either, a microcurrent or a sham treatment, on endurance performance. Additionally, changes in body composition, post-exercise lactate kinetics and perceived delayed onset of muscle soreness (DOMS) were determined. Eighteen males (32.8 ± 6.3 years) completed an 8-week endurance training programme involving 5 to 6 workouts per week wearing a microcurrent (MIC, n=9) or a sham (SH, n=9) device for 3-h post-workout or in the morning during non-training days. Measurements were conducted at pre- and post-intervention. Compared to baseline, both groups increased (P

Background In the context of a public health physical fitness (PF) examination in adolescence, a countermovement jump (CMJ) and a squat jump (SJ) are two vertical jump (VJ) tests widely used to evaluate lower limb muscle strength and power, respectively. The main criticism of both the CMJ and SJ test is the lack of test standardization. Therefore, the objectives of this review are: (a) to gather information about both jumps; (b) to investigate whether it is possible to identify common procedures referred to in the CMJ and SJ technical execution, and (c) to design standard operating procedures (SOPs) to promote CMJ and SJ standardization in an adolescent population aged 12-18 years. Methods The review partially adopted the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement (PRISMA). Due to growing attention in monitoring physical health through field tests in recent years, articles were collected using the PubMed, Web of Science, and Scopus databases from January 2009 to July 2019. Original articles in which CMJ or SJ were used to assess the muscular strength in adolescents were eligible for further analysis. Articles written in English was imposed as a limit. Results A total of 117 studies met the inclusion criteria. The description of the CMJ and SJ test procedures was different within the literature, with discrepancies in the jump technique, number of jumps, and measurement devices used. Conclusions A lack of method standardization for both the CMJ and the SJ test was identified. Based on the literature, SOPs for both VJs were proposed. These are useful in the context of public health PF examination in adolescents, as they facilitate an unbiased comparison of jump performance data between published studies.

Appropriate nutritional supplementation is crucial for athletic performance, particularly for female endurance athletes as their numbers steadily increase. This report involves a set of six case studies examining the effects of ingesting a post-workout supplement containing beef, or whey or carbohydrate on iron status, blood indices, muscular thickness, peak oxygen consumption (VO2 max) and body composition in six female masters-age (> 35 years old) triathletes. Over a 10-week training period, a 20 g supplement was ingested immediately post workout or during breakfast on the non-training days. Of the six analyzed cases, two ingested protein powder from beef, two consumed whey, and two consumed maltodextrin. Data showed that concomitant with increased dietary iron ingestion, levels of the iron-storage protein ferritin increased in beef-consumers (by 56% and 74 %) and carbohydrate-consumers (by 71% and 27 %), but decreased in whey-consumers (by 55% and 36%). Contrastingly, the effect on transferrin levels was highly variable between participants in each supplementation case. The whey-consumers showed reduced RBC count (by 6%), hematocrit (by 8%) and red blood cell distribution width (by 14% and 5%). While one beef-consumer showed a remarkable 34% increase in platelets, the whey and carbohydrate-consumers showed reduced platelets, but increased neutrophil: lymphocyte ratio. Vastus medialis thickness reduced in carbohydrate-consumers (by 6% and 5%), unlike the beef and whey-consumers. Females consuming beef increased iron stores and platelets, while those ingesting whey were unable to maintain specific RBC indices. Only the four athletes ingesting protein-containing supplements were able to maintain muscle thickness, thereby averting muscle loss. Funding Crown Sports Nutrition and the University of Greenwich provided joint funding for the completion of this project.

This study investigated the activity profile during small-sided games (SSG) in elite youth soccer players. Internal load (IL) including heart rate (HR) and external load (EL) such as distance covered in different speed-zones (SZ) were collected from forty-eight players of three different teams (U15, U16, U18). The investigation included a total of eighteen 5vs.5 SSGs, each consisting of four 2-minute bouts on a 40x32m pitch during spring season. Total group results (n = 48) showed a reduction in total-distance (p = 0.001; ηp2 = 0.12), high-intensity-running (p = 0.009; ηp2 = 0.09), and low-intensity-running distance (p = 0.028; ηp2 = 0.07) between bouts. Similarly, a reduction in the number of both acceleration-low (p = 0.001; ηp2 = 0.12) and deceleration-high (p = 0.003; ηp2 = 0.11) values was observed. Additionally, time spent in HR-zones 3 and 4 (p≤0.007; ηp2 ≥ 0.10), increased, with a reduction in HR-zone 1 (p = 0.000, ηp2 = 0.25). Age group comparison showed less distance covered in SZ 1 (p≤0.000; ηp2 = 0.56) and greater deceleration-high values (p≤0.038; ηp2 = 0.32) in U15 players compared to other age groups. Further, U15 showed lower values in low-intensity-running compared to U18 (p = 0.038; ηp2 = 0.22). No age-related differences were found for IL and repeated sprint ability (RSA) values. The higher EL in younger age groups should be taken into account when implementing soccer specific SSGs. In addition, HRmean values between 80–85% of HRmax and RSA numbers, which are similar to match-play data, indicate SSGs as an effective training tool to prepare youth soccer athletes for the demands of competition.

Introduction Microcurrent has been used to promote tissue healing after injury or to hasten muscle remodeling post exercise post exercise. Purpose To compare the effects of resistance training in combination with either, microcurrent or sham treatment, on-body composition and muscular architecture. Additionally, changes in performance and perceived delayed onset muscle soreness (DOMS) were determined. Methods Eighteen males (25.7 ± 7.6 years) completed an 8-week resistance training program involving 3 workouts per week (24 total sessions) wearing a microcurrent (MIC, n = 9) or a sham (SH, n = 9) device for 3-h post-workout or in the morning during non-training days. Measurements were conducted at pre and post intervention. Results Compared to baseline, both groups increased (p

BACKGROUND: Research supports a link between exercise and falls prevention in the older population. OBJECTIVES: Our aims were to evaluate pain perception and balance skills in a group of elderly subjects and to examine the consequences of a standardized equipment-free exercise program intervention on these variables. The study utilized a randomized controlled trial method. METHODS: 92 subjects were recruited from a rural Sicilian village (Resuttano, Sicily, Italy). Subjects were randomly split into two groups, an experimental group (EG; n = 49) and a control group (CG; n = 43). Qualified fitness instructors delivered the standardized physical exercise program for the EG whilst the CG did not receive this exercise intervention. The Berg Balance Scale and the Oswestry Disability Index were administered in both groups before (T0) and after the intervention (T1). RESULTS: At T1, the EG group significantly improvement in balance (p

The aim of this study was to analyze the effects on blood sugar concentrations through the calculation of the glycemic score (GS) of 10 different high-protein low-carbohydrates (CHOs) proprietary foods that are commonly used as meals during very low-CHO ketogenic diets or during low-CHO diets. Fourteen healthy females were tested for their glycemic response curve elicited by 1000 kJ of glucose three times within a 3-week period (one test each week) compared with one of 10 test foods once on separate days twice a week. After determining the GS of each food in each individual, the mean GS of each test food was calculated. All test foods, compared with glucose, produced a significantly lower glycemic response. The GS of all test food resulted in being lower than 25 and the difference between the mean glycemia after the intake of glucose (mean 122 ± 15 mg/dL) and after the intake of the sweet test foods (mean 89 ± 7 mg/dL) was 33 mg/dL (P

UNLABELLED:The objectives of this study were to examine the effects of a moderate intensity strength training on changes in critical velocity (CV), anaerobic running distance (D'), sprint performance and Yo-Yo intermittent running test (Yo-Yo IR1) performances. METHODS:two recreational soccer teams were divided in a soccer training only group (SO; n = 13) and a strength and soccer training group (ST; n = 13). Both groups were tested for values of CV, D', Yo-Yo IR1 distance and 30-m sprint time on two separate occasions (pre and post intervention). The ST group performed a concurrent 6-week upper and lower body strength and soccer training, whilst the SO group performed a soccer only training. RESULTS:after the re-test of all variables, the ST demonstrated significant improvements for both, YoYo IR1 distance (p = 0.002) and CV values (p

Purpose:To investigate the effects of a sport-specific maximal 6-wk strength and conditioning program on critical velocity (CV), anaerobic running distance (ARD), and 5-km time-trial performance (TT).Methods:16 moderately trained recreational endurance runners were tested for CV, ARD, and TT performances on 3 separate occasions (baseline, midstudy, and poststudy).Design:Participants were randomly allocated into a strength and conditioning group (S&C; n = 8) and a comparison endurance-trainingonly group (EO; n = 8). During the first phase of the study (6 wk), the S&C group performed concurrent maximal strength and endurance training, while the EO group performed endurance-only training. After the retest of all variables (midstudy), both groups subsequently, during phase 2, performed another 6 wk of endurance-only training that was followed by poststudy tests.Results:No significant change for CV was identified in either group. The S&C group demonstrated a significant decrease for ARD values after phases 1 and 2 of the study. TT performances were significantly different in the S&C group after the intervention, with a performance improvement of 3.62%. This performance increase returned close to baseline after the 6-wk endurance-only training.Conclusion:Combining a 6-wk resistance-training program with endurance training significantly improves 5-km TT performance. Removing strength training results in some loss of those performance improvements.

Detrimental effects of acute and chronic alcohol (ethanol) consumption on human physiology are well documented in the literature. These adversely influence neural, metabolic, cardiovascular, and thermoregulatory functions. However, the side effects of ethanol consumption on hormonal fluctuations and subsequent related skeletal muscle alterations have received less attention and as such are not entirely understood. The focus of this review is to identify the side effects of ethanol consumption on the major hormones related to muscle metabolism and clarify how the hormonal profiles are altered by such consumption.

Recent data suggest that the mean power over the final 30 seconds of a 3- min all-out test is equivalent to Critical Power (CP) using the linear ergometer mode. The purpose of the present study was to identify whether this is also true using an 'isokinetic mode'. Thirteen cyclists performed: 1) a ramp test; 2) three 3-min all-out trials to establish End Power (EP) and work done above EP (WEP); and 3) three constant work rate trials to determine CP and the work done above CP (W') using the work–time (=CP1/ W'1) and 1/time (=CP2/ W'2) models. Coefficient of variation in EP was 4.45% between trials 1 and 2, and 4.29% between trials 2 and 3. Limits of Agreement for trials 1-2 and trials 2-3 were -2 ± 38 W. Significant differences were observed between EP and CP1 (+37 W, P < 0.001), WEP and W′ 1(-6.2 kJ, P = 0.001), EP and CP2 (+31 W, P < 0.001), and WEP and W′ 2 (-4.2 kJ, P = 0.006). Average SEE values for EP-CP1 and EP – CP2 of 7.1% and 6.6% respectively were identified. Data suggest that using an isokinetic mode 3-min all-out test, whilst yielding a reliable measure of EP, does not provide a valid measure of CP.

Detrimental effects of acute and chronic alcohol (ethanol) consumption on human physiology are well documented in the literature. These adversely influence neural, metabolic, cardiovascular, and thermoregulatory functions. However, the side effects of ethanol consumption on hormonal fluctuations and subsequent related skeletal muscle alterations have received less attention and as such are not entirely understood. The focus of this review is to identify the side effects of ethanol consumption on the major hormones related to muscle metabolism and clarify how the hormonal profiles are altered by such consumption.