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Self-paced exercise protocols have gained attention for their potential to optimize performance and manage fatigue by allowing individuals to regulate their efforts based on perceived exertion. This pilot study aimed to investigate the neural and physiological responses during a self-paced V ˙ O2max (SPV) and incremental exercise tests (IET). Six trained male cyclists (mean age 39.2 ± 13.3 years; V ˙ O2max 54.3 ± 8.2 mL·kg−1·min−1) performed both tests while recording their brain activity using electroencephalography (EEG). The IET protocol involved increasing the power every 3 min relative to body weight, while the SPV allowed participants to self-regulate the intensity using ratings of perceived exertion (RPE). Gas exchange, EEG, heart rate (HR), stroke volume (SV), and power output were continuously monitored. Statistical analyses included a two-way repeated measures ANOVA and Wilcoxon signed-rank tests to assess differences in alpha and beta power spectral densities (PSDs) and the EEG/ V ˙ O2 ratio. Our results showed that during the SPV test, the beta PSD initially increased but stabilized at around 80% of the test duration, suggesting effective management of effort without further neural strain. In contrast, the IET showed a continuous increase in beta activity, indicating greater neural demand and potentially leading to an earlier onset of fatigue. Additionally, participants maintained similar cardiorespiratory parameters ( V ˙ O2, HR, SV, respiratory frequency, etc.) across both protocols, reinforcing the reliability of the RPE scale in guiding exercise intensity. These findings suggest that SPV better optimizes neural efficiency and delays fatigue compared to fixed protocols and that individuals can accurately control exercise intensity based on perceived exertion. Despite the small sample size, the results provide valuable insights into the potential benefits of self-paced exercise for improving adherence to exercise programs and optimizing performance across different populations. [ABSTRACT FROM AUTHOR]

Background: The value of maximal oxygen uptake (VO2MAX) is a key health indicator. Usually, VO2MAX is determined with cardiopulmonary exercise testing (CPET), which is cumbersome and time-consuming, making it impractical in many testing scenarios. The aim of this study is to validate a novel seismocardiography sensor (Seismofit®, VentriJect DK, Hellerup, Denmark) for non-exercise estimation of VO2MAX. Methods: A cohort of 94 healthy subjects (52% females, 48.2 (8.7) years old) were included in this study. All subjects performed an ergometer CPET. Seismofit® measurements were obtained 10 and 5 min before CPET in resting condition and 5 min after exhaustion. Results: The CPET VO2MAX was 37.2 (8.6) mL/min/kg, which was not different from the two first Seismofit® estimates at 37.5 (8.1) mL/min/kg (p = 0.28) and 37.3 (7.8) mL/min/kg (p = 0.66). Post-exercise Seismofit® was 33.8 (7.1) mL/min/kg (p < 0.001). The correlation between the CPET and the Seismofit® was r = 0.834 and r = 0.832 for the two first estimates, and the mean average percentage error was 11.4% and 11.2%. Intraclass correlation coefficients between the first and second Seismofit® measurement was 0.993, indicating excellent test-retest reliability. Conclusion: The novel Seismofit® VO2MAX estimate correlates well with CPET VO2MAX, and the accuracy is acceptable for general health assessment. The repeatability of Seismofit® estimates obtained at rest was very high. [ABSTRACT FROM AUTHOR]

Background: Evidence regarding the performance-related effects of Actovegin is limited, despite legislated restrictions being in place for this supplement within sport settings. Objectives: Our study examined the effects of Actovegin on physiological responses and performance during maximal cardiopulmonary exercise in collegiate athletes. Methods: A randomized, double-blind, placebo-controlled experimental design was adopted. Moderately trained collegiate athletes from various sports were randomly allocated to placebo (n = 8) or Actovegin (n = 8) groups. All athletes consumed three capsules across each day for seven days of loading. Athletes underwent two separate cardiopulmonary exercise tests one week apart. Separate 2 × 2 mixed ANOVAs and effect sizes ( η p 2 ) were used to assess for between- and within-group differences. Results: A significant time * group effect (p = 0.036, η p 2 = 0.278) was observed in systolic blood pressure. Significant main effects were only observed for time in several variables, with increases in peak oxygen uptake (VO2) (p < 0.001, η p 2 = 0.893), peak minute ventilation (p = 0.004, η p 2 = 0.456), ventilatory equivalents for carbon dioxide (p = 0.002, η p 2 = 0.517), oxygen pulse (p = 0.006, η p 2 = 0.434), VO2 at first ventilatory threshold (p = 0.002, η p 2 = 0.520), velocity at second ventilatory threshold (p < 0.001, η p 2 = 0.997), VO2 at second ventilatory threshold (p < 0.001, η p 2 = 0.628), and peak velocity (p = 0.010, η p 2 = 0.386), and a decrease in respiratory exchange ratio (p < 0.001, η p 2 = 0.695). Conclusions: Our findings suggest that although physiological and performance alterations were evident with Actovegin supplementation during cardiopulmonary exercise, no further benefits beyond those obtained with a placebo were attained. [ABSTRACT FROM AUTHOR]

Featured Application: Hearing impairment is not a barrier in the development of an athlete's physical fitness. Inclusion in sports participation and specific tools (i.e., communication aids) appear to be crucial factors in the performance enhancement of deaf and hard-of-hearing athletes. The aim of this systematic review was twofold: to identify the main trends and issues that are being addressed by researchers in the context of physical fitness and sports performance in deaf and hard-of-hearing (D/HH) athletes and to indicate the needs and future directions that should be implemented in the training process of athletes with hearing impairments. The methodology of this systematic review was planned according to PRISMA guidelines. A search of electronic databases (PubMed, EBSCO, Scopus) was conducted to identify all studies on physical fitness, sports performance and participation, and D/HH athletes from 2003 to 2024. In total, 87 full-text articles were assessed to determine eligibility, while 34 studies met the inclusion criteria and were subjected to detailed analysis and assessment of their methodological quality. The presented systematic review indicates evidence that D/HH athletes are characterized by a similar or higher level in selected motor abilities compared to hearing athletes. Moreover, it seems that hearing impairment is not a barrier in the development of an athlete's physical fitness, including aerobic capacity, muscular strength and power or speed of reaction. Furthermore, inclusion in sports participation and specific tools (i.e., communication aids) appear to be crucial factors for performance enhancement. [ABSTRACT FROM AUTHOR]

Chest deformities in children with scoliosis may result in cardiopulmonary disorders, lowering cardiopulmonary capacity levels. However, results regarding the dependence of cardiopulmonary capacity on the severity level of scoliosis remain controversial. We aimed to use dynamic cardiopulmonary exercise testing (CPET) to investigate exercise capacity in reference to spinal deformity in patients with mild or moderate idiopathic scoliosis by means of multivariate analyses. Methods: We included 92 children and adolescents aged 10–17 years with mild and moderate idiopathic scoliosis and 94 healthy peers. The study consisted of three parts: (1) medical record analyses; (2) anthropometric measurements; and (3) CPET. Results: Our results revealed that the mean VO2peak and VO2peak/kg values of the participants with scoliosis were 0.27 L/min and 0.37 mL/min/kg lower than their healthy peers, respectively, regardless of age and gender. Furthermore, the occurrence of scoliosis correlates with a mean decrease in minute ventilation volume by 10.10 L/min, tidal volume by 0.11 L, breathing frequency by 3.78 bpm, and breathing reserve by 14.34%, regardless of the age and gender of the participants. Children and adolescents with mild-to-moderate scoliosis during CPET exhibit a lower ventilation capacity and lower VO2 max than healthy adolescents matched in age but their cardiorespiratory fitness parameters do not depend on the Cobb angle value and the angle rotation of the primary spinal curvature. Conclusions: Physical therapy and activity should be recommended to prevent cardiorespiratory failure in later life in patients with scoliosis. This study may also provide CPET reference values for healthy children and adolescents with scoliosis. [ABSTRACT FROM AUTHOR]

This review investigates the effect of two different concurrent training sequences on endurance performance. The sequences investigated are Endurance–Resistance (ER) and Resistance–Endurance (RE). A literature search is conducted of the SPORTDiscus and Medline databases. The included studies are randomized control trials, which compare the effect of ER and RE on at least one endurance performance variable. A PEDro scale is used to assess the methodological quality of the articles in this review. Of a total of 152 articles identified during the initial screening, 15 studies meet the inclusion criteria. These studies include 426 participants (298 males and 128 females), with 212 of the participants training with ER and 214 with RE. The results are presented as the percentage change of the mean from pre- to post-test. All the studies show an improvement in endurance from pre to post for both interventions, except for the RE group in one study. This review finds small and non-conclusive sequence effects between ER and RE, suggesting that the sequence of concurrent training is not of great importance in relation to endurance performance. [ABSTRACT FROM AUTHOR]

Purpose: This study investigated the impact of four weeks of age-dependent detraining on army soldiers' cardiorespiratory fitness and maximal and explosive strength. Methods: Fourteen volunteer tactical athletes participated, divided into two age groups (20 to 29 and 30 to 40 years). Before and after the detraining period, we assessed their anthropometric measurements (weight, height, body mass index, fat mass, and fat-free mass), cardiorespiratory fitness (maximal oxygen uptake [VO2max] and ventilatory thresholds [VT1 and VT2]), and kinematic properties during a single-leg counter-moving jump (CMJ) test for both the dominant and non-dominant legs. Two-way ANOVA followed by the Holm–Sidak post hoc test was used. Results: The anthropometric and cardiovascular variables did not show significant differences between the groups. However, both groups exhibited a significantly reduced maximum time and speed at the VO2max. Furthermore, the flight time and maximum height during the CMJ significantly decreased in the non-dominant leg for both age groups. Notably, the dominant leg's concentric impulse (CI) significantly reduced during the CMJ, but this effect was observed only in the 30–40 age group. There were significant differences between the two age groups. Conclusions: Our findings suggest that four weeks of detraining negatively impacts aerobic fitness and muscular strength, independently of age. However, the dominant leg may be more susceptible to detraining effects in army soldiers aged 30–40. Furthermore, as a perspective, our results strongly suggest that a detraining period could affect successful missions (aerobic performance deterioration), as well as promote a muscle imbalance between the legs, which could encourage muscle injuries and endanger combat missions. [ABSTRACT FROM AUTHOR]

Cardiac deaths account for the largest share of on-duty firefighter deaths. To help ensure duty fitness and minimize injury risk, many fire departments require the passing of an annual physical ability test, consisting of a battery of simulated fire suppression activities (sFSAs). The purpose of the study was to determine the relationship of sFSA performance to acute cardiac and respiratory events (ACREs) and the effect that estimated VO2max has on sFSA performance. The study was retrospective. As part of an annual physical ability test, five timed sFSAs were performed, summed for a composite time, and categorized into three performance levels (fast, moderate, and slow). Estimated VO2max was determined using the Forestry Step Test. A significant (p = 0.023) linear trend was observed with higher sFSA performance times being associated with a higher proportion of firefighters going on to suffer an ACRE. The estimated VO2max was significantly (p < 0.001) higher in the fast group compared to the slow group. There was not a significant (p = 0.70) difference in estimated VO2max between the moderate and slow groups. Estimated VO2max performance and sFSA performance were significantly correlated, with rs(488) = −0.272 and p < 0.001. Poorer sFSA performance was found to be associated with a higher proportion of ACREs. The results suggest that sFSA performance may be a valid indicator of ACRE injury risk and aerobic capacity. [ABSTRACT FROM AUTHOR]

The aim of the study was to examine the association between cardiorespiratory and metabolic parameters and match running performance (MRP) in highly trained football players. The sample of participants consisted of 41 national-level football players (aged 23.20 ± 3.40 years, body height 182.00 ± 5.15 cm, and body mass 76.86 ± 6.06 kg) from the Serbian Super league. For the purposes of this research, the following measurements were applied. A maximal multistage progressive treadmill test, with a direct measurement of maximal oxygen consumption (VO2max) (using Fitmate MED, Cosmed, Rome, Italy) was conducted, alongside continuous heart rate monitoring. Capillary blood samples were taken from the hyperemic area using specific test strips, and, after sample collection, lactate concentration was immediately determined using a lactate analyzer. MRP variables were analyzed according to the BioIRC model of motion structure analysis, based on existing standards for profiling movement intensity. The results of multiple regression analysis indicated an association between cardiac parameters and total distance (R2 = 54.3%, p = 0.000), high-speed running (R2 = 46.4%, p = 0.000), and jogging (R2 = 33.6%, p = 0.004). Regression analysis revealed an association between cardiorespiratory parameters and total distance (R2 = 24.8%, p = 0.014), and high-speed running (R2 = 20%, p = 0.039). Meanwhile, no association was found between lactate concentration and running performance. The explanation for these regression analysis results is based on the observation that functional abilities represent significant potential for expressing movement performance, a crucial condition for success in football. [ABSTRACT FROM AUTHOR]

The objectives of this study were to investigate (a) the relationship between the Yo-Yo intermittent recovery test level 1 (YYIR1) and a laboratory test for measuring maximal oxygen uptake (VO2max), (b) the relationships between anthropometric characteristics and variables of the two aerobic tests (field and laboratory), and (c) differences in performance and anthropometric characteristics among five different playing positions. The study involved 27 U17 young soccer players (16.0 ± 0.6 years). They randomly underwent a maximal laboratory treadmill test to measure VO2max and the YYIR1 test. Pearson correlation was used to find potential correlations, and a one-way ANOVA was used to find differences between playing positions. Statistical significance was set at p < 0.05. The results showed that height was moderately negatively correlated (r = −0.455, p = 0.017) as well as body mass (r = −0.395, p = 0.042). Significant positive correlation was observed between vVO2max and the distance covered in YYIR1 (r = 0.393, p = 0.042). Finally, no differences were observed between playing positions in any anthropometric characteristic or in any variable of the two aerobic tests (laboratory or field) (p > 0.05). In conclusion, the YYIR1 test is not suitable for estimating VO2max. Additionally, the lack of differences between playing positions may be due to the limited specialization of the training load received by the players until this age. [ABSTRACT FROM AUTHOR]

This study compared the acute physiological responses and performance changes during an integrated high-intensity interval aerobic and power protocol. Sixteen moderately trained athletes (age: 20.1 ± 2.2 years, body height: 180.0 ± 6.5 cm, body mass: 75.7 ± 6.4 kg, VO2max: 55.8 ± 4.3 mL/kg/min) performed a 2 × 6 min interval training protocol with 2 min passive recovery between sets on two different occasions in random and counterbalanced order. Each 6 min set included repeated periods of 15 s exercise interspersed with 15 s passive rest. On one occasion (RUN), all exercise periods included running at 100% of maximal aerobic speed, while on the other occasion an integrated protocol was used (INT) in which each of the two 6 min sets included 4 × 1.5 min periods of running exercise at 100% of maximal aerobic speed in combination with jumping (i.e., 2 × 15 running with 15 s rest and 1 × 15 s drop jumping with 15 s rest). Time spent above 85% HRmax was two-fold higher in INT compared to RUN (8.5 ± 3.6 vs. 4.3 ± 3.9 min, respectively, p = 0.0014). Interestingly, heart rate increased above 95% HRmax only in INT and almost no time was spent above 95% HRmax in RUN (1.4 ± 1.9 vs. 0.1 ± 0.2 min, respectively, p = 0.008). Blood lactate concentration at the end of the second set of INT was higher than RUN (7.3 ± 3.2 vs. 4.6 ± 2.7 mmol/L, p = 0.002). Countermovement jump was higher in INT after the end of second set by 6.4% (p = 0.04), 6.7% (p = 0.04), 7.8% (p < 0.01) and 7.3% (p < 0.001), at 2, 6 and 8 min after set 2. In conclusion, the comparison between INT and RUN shows that INT not only elicits higher physiological and metabolic responses, but also acutely enhances neuromuscular performance for at least 8 min after the end of exercise. The integrated running/jumping high-intensity interval exercise approach could be a very useful and time efficient method for strength and conditioning coaches, especially in team sports, in which the time available for the improvement of physical parameters is limited. [ABSTRACT FROM AUTHOR]

Insufficient physical activity (PA) is associated with low cardiorespiratory fitness, which favors cardiovascular and other noncommunicable diseases. Additionally, it evidentially affects mental health. Considering the WHO PA guidelines, CrossFit® represents a versatile exercise program that combines aerobic and resistance training with mobility and could help reduce disease incidences among sedentary people. Yet, long-term CrossFit research is sparse. We conducted a nine-month intervention (≥2 CrossFit workouts/week) in 16 beginners (14 males, 35 ± 6.8 years, 180 ± 8.6 cm, 85. 5 ± 19.1 kg). As a primary endpoint, VO2max was assessed at baseline, four, and nine months. A repeated-measures ANOVA and Pearson correlation were conducted. Well-being was investigated by the WHO-5 Index pre- and post-intervention. For exploratory purposes, body composition and heart rate recovery (HRR) were tracked. In a second step, all males were categorized into two groups based on body fat percentage and analyzed by repeated measures ANOVA again. The main outcome was an 11.5% VO2max improvement with a large effect (p < 0.01, η p 2 = 0.27). Strong negative correlations between baseline VO2max and its progression after nine months (p = 0.006, r = −0.654) were found. Well-being increased by 8.7% (p = 0.024, d = 0.51). HRR improved both at 1 min (p < 0.05, η p 2 = 0.34) and at 5 min (p < 0.05, η p 2 = 0.27) post-exercise. Resting metabolic rate increased by 2.2% (p = 0.042). Analysis by group revealed improved HRR at 1 min (p < 0.05, η p 2 = 0.62) only for the "high body fat" group. This study reveals the potential of CrossFit to enhance physiological and psychological health in beginners. For more robust results, larger sample sizes with a higher proportion of women are needed. [ABSTRACT FROM AUTHOR]

Due to limited accessibility, direct measurement of VO2max is rarely performed in clinical settings or sports centers. As a result, regression equations have been developed and are currently used during exercise tests to provide an indirect estimation. The American College of Sports Medicine (ACSM) has recommended a regression equation for running to provide an indirect estimation of VO2. However, significant differences have been observed between these estimations and directly measured VO2max. Additionally, since submaximal assessments may be more convenient for both athletes and sedentary/diseased individuals, they were included in the analysis. This study aimed to evaluate the accuracy of VO2max estimations provided using the ACSM running equation when used during both maximal and submaximal exercise tests among adult runners. A total of 99 apparently healthy and active adults (age: 39.9 ± 12.2 years; VO2max: 47.4 ± 6.0 mL O2/kg∙min−1) participated in this study. Two types of submaximal estimations were performed to predict VO2max: one based on age-predicted maximal heart rate (HRmax) (ACSMsubmax,Fox), and the second using the actual HRmax measured during the exercise test (ACSMsubmax,measured). The measured VO2max was compared to these estimations obtained from a single exercise test. Both maximal and submaximal exercise tests significantly overestimated VO2max (ACSMmax: +9.8, p < 0.001; ACSMsubmax,Fox: +3.4, p < 0.001; ACSMsubmax,measured: +3.8 mL O2/kg∙min−1, p < 0.001). However, the submaximal estimations were closer to the measured VO2max (p < 0.001). This analysis demonstrated that the included methods overestimated the true VO2max. Nonetheless, the submaximal exercise tests provided a more accurate prediction of VO2max compared to the maximal exercise tests when using the ACSM running equation. [ABSTRACT FROM AUTHOR]

Aerobic capacity is crucial for the performance of soccer players; however, the relationship between VO2max and the running performance of soccer players with visual impairment is not known. Possibly finding relationships would help in the training process, as training would be more targeted. Additionally, both bodyweight and relative VO2max are factors that affect people's health and wellness. From the literature, it appears that there are no studies that present the normal profile of soccer players with visual impairment. The aims of this study were to (a) determine the differences in VO2max between soccer players and sedentary men with visual impairment; (b) to assess the relationship between the VO2max of players with visual impairment and the distance covered in a soccer match and (c) to describe a profile of physiological parameters and distance running during a soccer match. Six male soccer players with VI and six male sedentary people with VI participated in this study. Anthropometric characteristics (age, height, bodyweight, body fat (BF), body mass index (BMI), cardiorespiratory markers (VO2max, maximum heart rate (HRmax), respiratory exchange ratio (RER)) and the running performance of soccer players during matches were measured, and the VO2max of all the participants was measured in a laboratory. Mann–Whitney U test was used to evaluate differences between sedentary and soccer players' anthropometric characteristics and performance. A correlation analysis by Spearman's' method was used to examine relationships between VO2max and the rest of the physical values during the match. The level of statistical significance was set at p < 0.05. The soccer players' weight was 33% lower, and their BMI was 23% lower than that of sedentary men (p = 0.023, η2 = 0.457 and p = 0.048, η2 = 0.394, respectively). The relative body mass VO2max of the athletes was 42.9% higher in comparison with sedentary men with VI (p = 0.002, η2 = 0.755). No correlations were found between VO2max and match running performance (p = 0.957, r = −0.029) or other parameters during the match in soccer players with VI. In conclusion, relative VO2max is not related to the match running performance of soccer players. The tactics applied by the team, the style of play and the position of the player may affect the distances covered. Also, as expected, the soccer players showed lower bodyweight and higher relative VO2max. However, this is the first study to observe the level of these differences. [ABSTRACT FROM AUTHOR]

Sarcopenic obesity (SO) constitutes the coexistence of skeletal muscle mass loss (sarcopenia) and excess adiposity (obesity). It is mainly considered as a condition in the elderly with health-threatening impacts ranging from frailty to mortality. Mitochondrial dysfunction consists one of the basic pathophysiological mechanisms leading to the development of SO and its consequences. Indirect indicators of mitochondrial function, such as VO2max and exercise capacity, have been demonstrated to be negatively affected in individuals with SO, while the positive effect of exercise on mitochondrial function has been widely proved; thus, in this review, we aimed at investigating the effects of endurance, resistance, and concurrent exercise training on indexes of mitochondrial dysfunction in SO patients. The results of the clinical trials evaluated reveal positive effects of chronic exercise on VO2max and physical capacity, as well as mitochondrial biogenesis and activity. It has been concluded that utilizing a systematic exercise training program that includes both aerobic and strength exercises can be an effective strategy for managing SO and promoting overall health in these patients. [ABSTRACT FROM AUTHOR]

This study investigated the cardiac functional and the morphological adaptations because of two endurance training protocols. Untrained children (N = 30, age: 12–14 years) were divided into three groups (N = 10/group). The first group did not perform any session (CONTROL), the second performed ventilatory threshold endurance training (VTT) for 12 weeks (2 sessions/week) at an intensity corresponding to the ventilatory threshold (VT) and the third (IT) performed two sessions per week at 120% of maximal oxygen uptake (VO2max). Two other sessions (30 min running at 55–65% of VO2max) per week were performed in VVT and IT. Echocardiograms (Left Ventricular end Diastolic Diameter, LVEDd; Left Ventricular end Diastolic Volume, LVEDV; Stroke Volume, SV; Ejection Fraction, EF; Posterior Wall Thickness of the Left Ventricle, PWTLV) and cardiopulmonary ergospirometry (VO2max, VT, velocity at VO2max (vVO2max), time in vVO2max until exhaustion (Tlim) was conducted before and after protocols. Significant increases were observed in both training groups in LVEDd (VTT = 5%; IT = 3.64%), in LVEDV (VTT = 23.7%; ITT = 13.6%), in SV (VTT = 25%; IT = 16.9%) but not in PWTLV and EF, after protocols. No differences were noted in the CONTROL group. VO2max and VT increased significantly in both training groups by approximately 9% after training. Our results indicate that intensity endurance training does not induce meaningful functional and morphological perturbations in the hearts of children. [ABSTRACT FROM AUTHOR]

The aim of the research was to identify the effect of 4vs.4 small-sided games (SSGs) with goalkeepers (4vs.4+GK), applied twice a week, for 8 weeks, on U18 football players' physical ability, compared to that of the athletes who performed specific aerobic endurance training. The research included 40 football players U18, divided into two groups: 20 in the experiment group (EG) aged 17.49 ± 0.61 years and 20 in the control group (CG) aged 17.66 ± 0.54 years. From the initial test (IT) to final tests (FT) performed on the parameters, maximum oxygen consumption (VO2max) and 10 m and 20 m sprint and agility with and without a ball showed a significant increase for both groups. The first and last SSG training was monitored, using total distance (TD), high-intensity distance (HSR—high-speed running) and maximum intensity distance (VHSR—very-high-speed running). Comparative analyses of EG and CG parameters at the FT shows that the differences between the means of two groups are statistically significant in favor of the experimental group in terms of all parameters, except 10 m sprint (p < 0.05). Referring to SSGs, the experimental group had a 7.78% increase rate in TD (p < 0.0005), a 30.90% (p < 0.0005) increase rate with HSR and no significant differences (p > 0.05) with VHSR. The experimental training program of 4vs.4+GK SSGs, applied to U18 football players, produced significant progress in the physical, and functional parameters. [ABSTRACT FROM AUTHOR]

When combining two conditions of reduced oxygen availability, anemia and hypoxia, human physiological responses are highly challenged to maintain arterial oxygen delivery, especially during whole-body exercise. The aim of this study was to compare the cardiorespiratory responses of mildly anemic women with those of healthy controls, while cycling in normobaric hypoxia. Two groups of young females were matched for age, weight, height, and involvement in physical activity, one with normal hemoglobin, hematocrit, and ferritin levels and another suffering from mild iron deficiency anemia (10 < (Hb) < 12 g/dL, 34 < Hct < 37%, ferritin < 15 μg/L). They cycled to exhaustion under normoxia and hypoxia (FIO2 0.21 and 0.14), and their physiological responses were compared at 40, 80, and 100% VO2max of the specific condition. The two groups differed (p < 0.05) mainly at the higher exercise intensities; the anemic participants exhibited similar heart rate but lower oxygen pulse than their control counterparts, as well as a larger drop in maximal oxygen uptake. However, they sustained maximal effort by employing the anaerobic metabolism to a larger extent, which stimulated a greater ventilatory response. It appears that iron deficiency anemia of mild severity, which is commonly observed in young athletic females, impacts physiological responses during whole-body exercise in the presence of moderate hypoxia. [ABSTRACT FROM AUTHOR]

Apelin, as a cardiokine/myokine, is emerging as an important regulator of cardiac and skeletal muscle homeostasis. Loss of apelin signaling results in premature cardiac aging and sarcopenia. However, the contribution of apelin to peak athletic performance remains largely elusive. In this paper, we assessed the impact of maximal cardiorespiratory exercise testing on the plasma apelin levels of 58 male professional soccer players. Circulating apelin-13 and apelin-36, on average, increased transiently after a single bout of treadmill exercise; however, apelin responses (Δapelin = peak − baseline values) showed a striking interindividual variability. Baseline apelin-13 levels were inversely correlated with those of Δapelin-13 and Δapelin-36. Δapelin-13 showed a positive correlation with the maximal metabolic equivalent, relative maximal O2 consumption, and peak circulatory power, whereas such an association in the case of Δapelin-36 could not be detected. In conclusion, we observed a pronounced individual-to-individual variation in exercise-induced changes in the plasma levels of apelin-13 and apelin-36. Since changes in plasma apelin-13 levels correlated with the indicators of physical performance, whole-body oxygen consumption and pumping capability of the heart, apelin, as a novel exerkine, may be a determinant of peak athletic performance. [ABSTRACT FROM AUTHOR]

(1) Background: Applying medical procedures to keep track of athletes' metabolic health is a well-known behavior for increasing sports performance. This study's primary goal was to examine whether implementing a health-screening routine using invasive and non-invasive methods in a mountain running training program can increase sports performance by obtaining a better rank in specific races. (2) Methods: Seven male mountain runners with good results at the international level participated in the research, which featured an initial and a final test. The initial test took place in March at the beginning of the competitive season, and the final test took place in September at the end of the annual training plan in 2021. The entire experiment used invasive tests, such as taking blood samples to perform blood biochemistry analysis, and non-invasive tests, such as mountain running races, determinations of VO2max, EKGs, urine biochemistry and NeuroTracker tests. (3) Results: Comparing the initial test with the final one from a statistical point of view, a significant improvement was found in the final test regarding the obtained results in most tests and, most importantly, the occupied position in the final general rank (p = 0.005). The main variations after effort were decreased Ca++ and increased Cl−, a low TGL level if the diet was inadequate, increased LDH and CPK strongly correlated with the skeletal muscle response, and only physiological changes were found in the EKG and urine summary. (4) Conclusions: The invasive and non-invasive tests applied in this study provided crucial information on the athletes' health statuses, enabling the coach to adjust the training program in light of the findings in order to improve sports performance and avoid overexertion. [ABSTRACT FROM AUTHOR]

Road cycling is an endurance sport characterized by several anthropometric performance factors, such as reduced body mass and body fat percentage. As the power to weight ratio is considered one of the most important markers of performance in this sport discipline, it is speculated that anthropometric factors could relate to the physiological parameters found in road cyclists of different performance levels. The current study aimed to describe the anthropometric differences across road cyclists of different performance levels and to assess whether anthropometric values could relate to physiological markers that are commonly used to classify road cyclists, according to their performance level. We classified 46 cyclists as recreationally trained, trained, well trained and professional, according to their VO2max, and performed graded exercise tests and complete anthropometric assessments. The results showed that there were no significant anthropometric differences between trained, well trained and professional cyclists, with only recreationally trained cyclists exhibiting larger perimeters and skinfolds than professional cyclists. Further, although physiological performance, such as VO2max and respiratory compensation point, correlated negatively with several skinfolds and perimeters, these correlations remained restrained and did not distinguish between cyclists of different specialties. [ABSTRACT FROM AUTHOR]

The aim of the present study was to describe the morphological and performance characteristics of elite handball players using data collected over the last two decades within the talent evaluation program of the Slovenian Handball Federation. A total of 1066 elite male handball players selected for one of the Slovenian national teams (U17, U19, U21 or senior) were recruited. The data were collected from 2007/8 to the 2021/22 season. The main effects were observed for: body height, body weight, and body mass index (BMI). The muscle mass percentage differed only between different age categories (p = 0.003; η2 = 0.015), while the fat mass percentage (FM%) differed between playing positions (p < 0.001; η2 = 0.107). Post-hoc comparisons showed that, within senior handball players, pivot players were 6.46 cm (p = 0.009) taller than wing players and heavier than goalkeepers (12.43 kg, p = 0.004), backcourts (13.30 kg, p < 0.001) and wings (17.83 kg, p < 0.001). Moreover, pivots had a greater BMI than goalkeepers (2.3 kg/m2, p = 0.003), backcourts (2.62 kg/m2, p < 0.001), and wings (3.07 kg/m2, p < 0.001), while FM% was significantly higher in pivots compared to wings (4.32%, p = 0.010). Taking into consideration playing positions and age, the main effects were also observed for squat jump height, countermovement jump height, end-running speed, and VO2max (all p < 0.001; η2 = 0.017 to 0.091). Both morphological and performance characteristics clearly differ across playing positions and age categories, which should be a valuable guide for coaches to develop position-specific talent identification programs and training plans. [ABSTRACT FROM AUTHOR]

Background: The aim of this study is to use different regression models to capture the association between cardiorespiratory fitness VO2max (measured in mL/kg/min) and somatometric characteristics and sports activities and making better predictions. Methods: multiple linear regression (MLR), quantile regression (QR), ridge regression (RR), support vector regression (SVR) with three different kernels, artificial neural networks (ANNs), and boosted regression trees (RTs) were compared to explain and predict VO2max and to choose the best performance model. The sample consisted of 4908 children (2314 males and 2594 females) aged between 6 and 17. Cardiorespiratory fitness was assessed by the 20 m maximal multistage shuttle run test and maximal oxygen uptake (VO2max) was calculated. Welch t-tests, Mann–Whitney-U tests, X2 tests, and ANOVA tests were performed. The performance measures were root mean square error (RMSE), mean absolute error (MAE), and coefficient of determination (R2). All analyses were stratified by gender. Results: A comparison of the statistical indices for both the predicted and actual data indicated that in boys, the MLR model outperformed all other models in all indices, followed by the linear SVR model. In girls, the MLR model performed better than the other models in R2 but was outperformed by SVR-RBF in terms of RMSE and MAE. The overweight and obesity categories in both sexes (p < 0.001) and maternal prepregnancy obesity in girls had a significant negative effect on VO2max. Age, weekly football training, track and field, basketball, and swimming had different positive effects based on gender. Conclusion: The MLR model showed remarkable performance against all other models and was competitive with the SVR models. In addition, this study's data showed that changes in cardiorespiratory fitness were dependent, to a different extent based on gender, on BMI category, weight, height, age, and participation in some organized sports activities. Predictors that are not considered modifiable, such as gender, can be used to guide targeted interventions and policies. [ABSTRACT FROM AUTHOR]

Background: Modern pentathlon includes horse riding, fencing, swimming, shooting and cross-country running. Events can last many hours during which the athletes face almost maximal energy and physiological demands, and fatigue. Early recognition and prevention of injuries and overuse syndromes can be achieved by refining the individual training loads. The purpose of the study was to determine which parameter could be the most accurate predictor of swimming working capacity determinants in pentathletes. Methods: Fourteen male pentathletes performed a continuous maximal incremental test in the swimming flume ergometer to measure peak oxygen uptake (VO2peak), and five swimming tests in a 50 m swimming pool to detect critical velocity (CV); velocity at 2 and 4 mM·L−1 of blood lactate (v2, v4) and energy cost (EC). Results: The 200 m swimming time was 2:18–2:32 m:s (340 FINA points). CV was 1.21 ± 0.04 m·s−1, v2 was 1.14 ± 0.09 and v4 1.23 ± 0.08 m·s−1. VO2peak was 3540.1 ± 306.2 mL·min−1 or 48.8 ± 4.6 mL·kg−1·min−1. EC at 1.24 m·s−1 was 45.7 ± 2.4 mL·kg−1·min−1. Our main finding was the large correlation of CV with 200 m swimming performance; Conclusions: Among all the protocols analysed, CV is the most predictive and discriminative of individual swimming performance in this group of pentathletes. It appears as the most suitable test to constantly refine their swimming training loads for both performance enhancement and health promotion. [ABSTRACT FROM AUTHOR]

Featured Application: The results presented in this study provide a reference point on the most important anthropometric determinants of women's futsal performance, which can help coaches to improve their performance. Futsal is classified as a high-intensity intermittent sport or repeated-sprint sport. Explosive and very fast movements are performed with short reaction time, interspersed with playing time of 3 to 6 min during the 40 min match, at intensities of 85–90% of maximum HR. Performance factors such as agility, sprint repetition capacity, aerobic endurance capacity, lower body power, and speed are associated with the game actions. These performance factors can be affected by the athlete's body composition. The aim is to determine the relationship between the different physical and physiological performance parameters and body composition in top-level women's futsal players. The subjects of the study were 12 elite female futsal players (25.17 ± 4.75 years old) competing in the First Division Spanish League. An anthropometric assessment was conducted by an ISAK level III anthropometrist for three days during the competitive period. The sum of 4, 6 and 8 skinfolds and body composition were calculated with anthropometric data. Performance tests were conducted to evaluate agility, ability to repeat sprints, velocity and the explosive power of lower extremities in the playing court with specific warm up and previous explication during 2 days in the same week as the anthropometric tests. The tests used for that purpose were: t-test, Yo-Yo test, repeat-sprint ability (RSA), speed test, and jump test (JS, CMJ and ABK). Pearson correlations were used to establish the different associations with a p-value < 0.05. The results showed a negative correlation between agility and the fat component, and a positive correlation between the muscle component and aerobic capacity, agility, speed, and ABK jump. Body composition plays a fundamental role in the development of performance-related skills in women's futsal. [ABSTRACT FROM AUTHOR]

The aim of this systematic review and meta-analysis was to evaluate the association between glycemic control (HbA1c) and functional capacity (VO2max) in individuals with type 1 diabetes (T1DM). A systematic literature search was conducted in EMBASE, PubMed, Cochrane Central Register of Controlled Trials, and ISI Web of Knowledge for publications from January 1950 until July 2020. Randomized and observational controlled trials with a minimum number of three participants were included if cardio-pulmonary exercise tests to determine VO2max and HbA1c measurement has been performed. Pooled mean values were estimated for VO2max and HbA1c and weighted Pearson correlation and meta-regression were performed to assess the association between these parameters. We included 187 studies with a total of 3278 individuals with T1DM. The pooled mean HbA1c value was 8.1% (95%CI; 7.9–8.3%), and relative VO2max was 38.5 mL/min/kg (37.3–39.6). The pooled mean VO2max was significantly lower (36.9 vs. 40.7, p = 0.001) in studies reporting a mean HbA1c > 7.5% compared to studies with a mean HbA1c ≤ 7.5%. Weighted Pearson correlation coefficient was r = −0.19 (p < 0.001) between VO2max and HbA1c. Meta-regression adjusted for age and sex showed a significant decrease of −0.94 mL/min/kg in VO2max per HbA1c increase of 1% (p = 0.024). In conclusion, we were able to determine a statistically significant correlation between HbA1c and VO2max in individuals with T1DM. However, as the correlation was only weak, the association of HbA1c and VO2max might not be of clinical relevance in individuals with T1DM. [ABSTRACT FROM AUTHOR]

The present study aimed to assess the changes in muscle strength and plasma metabolites in athletes with β-glucan supplementation. A total of 29 athletes who met the inclusion criteria were recruited for this study (ChiCTR2200058091) and were randomly divided into a placebo group (n = 14) and β-glucan group (n = 15). During the trial, the experimental group received β-glucan supplementation (2 g/d β-glucan) for 4 weeks and the control group received an equal dose of placebo supplementation (0 g/d β-glucan), with both groups maintaining their regular diet and exercise habits during the trial. The athletes' exercise performance, muscle strength, and plasma metabolome changes were analyzed after 4 weeks of β-glucan supplementation. The results showed a significant increase in mean grip strength (kg), right hand grip strength (kg), left triceps strength (kg), and upper limb muscle mass (kg) in the experimental group after the 4-week intervention compared to the preintervention period (p < 0.05). A comparison of the difference between the two groups after the intervention showed that there were significant differences between the control group and the experimental group in mean grip strength (kg) and right-hand grip strength (kg) (p < 0.05). Athletes in the experimental group showed significant improvements in 1 min double rocking jump (pcs), VO2max (ml/kg-min) (p < 0.05). The β-glucan intake increased the creatine-related pathway metabolites in plasma. Overall, these results suggest that 4 weeks of β-glucan supplementation can improve muscle strength in athletes, with the potential to increase aerobic endurance and enhance immune function, possibly by affecting creatine-related pathways. [ABSTRACT FROM AUTHOR]

HCO: untrained group receiving high-dose cocoa at 24.6 mg/kg b.w.; CONTEx: control exercise-trained group; COEx: exercise-trained group supplemented with cocoa at 8.2 mg/kg; HCOEx: exercise-trained group supplemented with high-dose cocoa at 24.6 mg/kg b.w. The performance of an exercise bout led to an elevation in oxidative stress, as supported by the TBARS and SOD data, and this was attenuated after 10 weeks in the both CT and CO groups by the practice of physical exercise and the increased physical condition, as expected [[47]], but this was more marked in athletes supplemented with cocoa, which may diminish the adaptations to exercise [[48]]. The period in which the supplementation occurred, during which time great adaptations to exercise were taking place, the framework of the athletes' diets, which were rich in fruits and vegetables, and the type of cocoa used in the study, could be determining factors in the observed effects of cocoa on athletes. (CO), (3) untrained group receiving high-dose cocoa at 24.6 mg/kg b.w (HCO), (4) control exercise-trained group (CONTEx), (5) exercise-trained group supplemented with cocoa at 8.2 mg/kg b.w. [Extracted from the article]

VO2max index has a significant impact on overall health. Its estimation through wearables notifies the user of his level of fitness but cannot provide a detailed analysis of the time intervals in which heartbeat dynamics are changed and/or fatigue is emerging. Here, we developed a multiple modality biosignal processing method to investigate running sessions to characterize in real time heartbeat dynamics in response to external energy demand. We isolated dynamic regimes whose fraction increases with the VO2max and with the emergence of neuromuscular fatigue. This analysis can be extremely valuable by providing personalized feedback about the user's fitness level improvement that can be realized by developing personalized exercise plans aimed to target a contextual increase in the dynamic regime fraction related to VO2max increase, at the expense of the dynamic regime fraction related to the emergence of fatigue. These strategies can ultimately result in the reduction in cardiovascular risk. [ABSTRACT FROM AUTHOR]

Simple Summary: Bioelectrical and body composition proprieties are linked to health status and physical performance. The bioelectrical impedance vector analysis (BIVA) is a valid approach for qualitatively and timely assessing body components in sports practice. However, it is still unclear, if bioimpedance vector patterns can provide relevant information regarding the aerobic power. For the first time, this study shows that BIVA is useful in discriminating professional futsal players according to their VO2max. In addition, fat mass and bioelectrical phase angle were identified as valid predictors for aerobic power. Aims: The present study aimed to assess the ability of bioelectrical impedance vector analysis (BIVA) in discriminating fitness levels in futsal players, exploring the association of body composition and bioelectrical parameters with aerobic power. Methods: Forty-eight professional futsal players (age 23.8 ± 5.3 years) were involved in a cross-sectional study during their pre-season phase. Fat mass (FM) and muscle mass were determined by dual-energy X-ray absorptiometry. VO2max was obtained by indirect calorimetry through a graded exercise test performed on a treadmill. Bioelectrical resistance (R), reactance (Xc), and phase angle (PhA) were directly measured using a foot-to-hand bioimpedance technology at a 50 kHz frequency. Bioelectric R and Xc were standardized for the participants' height and used to plot the bioimpedance vector in the R-Xc graph according to the BIVA approach. Results: The participants divided into groups of VO2max limited by tertiles showed significant differences in mean vector position in the R-Xc graph (p < 0.001), where a higher VO2max resulted in a longer vector and upper positioning. FM, muscle mass, and PhA differed (p < 0.01) among the athletes grouped by tertiles of VO2max, where athletes with a greater aerobic power showed a lower percentage of FM and a higher percentage of muscle mass and PhA. FM and PhA were associated with VO2max (FM: r = −0.658, p < 0.001; PhA: r = 0.493, p < 0.001). These relationships remained significant after adjusting for age and body mass (FM: ß = −0.335, p = 0.046; PhA: ß = 0.351, p = 0.003). Conclusions: Bioelectrical impedance vectors positioned on the lower pole of the R-Xc graph identified futsal players with a lower VO2max, while longer vectors corresponded to a greater aerobic power. Additionally, PhA, that describes the vector direction, was positively associated with VO2max, while a higher FM negatively affected VO2max in the futsal players. BIVA and PhA evaluation may represent a valid support for screening the aerobic fitness level in professional futsal players, when more sophisticated assessment methods are not available. [ABSTRACT FROM AUTHOR]

COVID-19 containment measures hampered population cardiorespiratory fitness (which can be quantified as peak oxygen consumption ( V. O2peak)) and the possibility to assess it using laboratory-based techniques. Although it is useful to ascertain the V. O2peak recovery after lockdowns, the community and most scientific institutions were unable to evaluate it. Wearable devices may provide the opportunity to estimate cardiorespiratory fitness outside of the laboratory, without breaking self-isolation; herein, we explore the feasibility of this approach. Fifteen healthy participants were tested every 2 weeks for 10 weeks during a reduction of containment measures after a strict lockdown. Physical activity levels were measured using the International Physical Activity Questionnaire-Short Form (IPAQ-SF). V. O2peak was estimated through a previously validated test based on the speed of a 60 m sprint run, the baseline-to-peak heart rate (HR) variation, and the velocity of HR decay after the sprint, and measured through a wearable HR monitor. Participants increased physical activity from the end of lockdown (1833 [917–2594] MET-min/week; median [1st quartile–3rd quartile]) until the end of follow-up (2730 [1325–3380] MET-min/week). The estimated V. O2peak increased by 0.24 ± 0.19 mL/(min*kg*week) (regression coefficient ± standard error). Based on previous knowledge on the impact of inactivity on V. O2peak, our study indicates that a 10-week period of reducing the stringency of containment measures may not be sufficient to counteract the detrimental effects of the preceding lockdown. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the validity of three submaximal exercise tests (SMETs) and develop practical predictive models for the VO2max in Korean adults. A total of 541 (287 males and 254 females) adults participated in this study. Their ages ranged from 19 to 64. The VO2max was measured using the maximal-graded exercise treadmill test. The SMETs were performed by a treadmill test, the YMCA step test, and the PACER test. Regression analysis was conducted to compare the validity of the VO2max predictive equations using SMETs. The validity of the predictive models was evaluated using explanatory power, standard error of estimate (SEE), and Bland-Altman analysis. The explanatory power between the measured VO2max and the predicted VO2max was 58.0% (<0.001), 59.2% (<0.001), and 71.7% (<0.001), respectively. The SEEs were 4.545, 4.478, and 3.732 (mL/kg/min). The models were significant predictors of VO2max and had acceptable validity in a large sample of Korean adults. Especially, among the predictive models, PACER had the highest acceptable effectiveness. Therefore, the equations developed in this study are recommended to better evaluate the cardiovascular endurance of Korean adults. [ABSTRACT FROM AUTHOR]

Background and Objectives: Angiogenesis describes the outgrowth of new capillaries from already existing ones. Different biomarkers regulate this process. Physical exercise and hypoxia are key stimuli for the activation of different angiogenic molecules, such as the vascular endothelial growth factor (VEGF). matrix metalloproteases (MMPs)-2 and -9 or the extracellular matrix cleavage fragment endostatin. The present study aimed to investigate influences of short-term, intensive cycling exercise under both normoxic and normobaric hypoxic conditions on the mentioned parameters. Materials and Methods: Twelve male subjects (age: 23.3 ± 2.0 years) participated in the study. All subjects conducted four intensive cycling tests until individual exhaustion in a randomized order under the following conditions: normoxia, 2000 m, 3000 m and 4000 m above sea level. Blood samples were taken before (pre) and 10 min, 30 min, 60 min and 240 min post exercise and were analyzed by ELISA. Results: VEGF showed a significantly reduced concentration compared to the pre-value solely under 4000 m at 10 min post exercise. MMP-2 showed significantly reduced concentrations at 240 min post exercise under 4000 m. MMP-9 increased at 240 min post exercise under both 2000 m and 4000 m conditions. Endostatin was significantly increased at 10 min post exercise independently of the applied stimulus. Conclusions: The presented data show that intensive short-term exercise bouts facilitate the bioavailability of angiogenic, ECM (extracellular matrix)-related biomarkers. This finding is interesting for both health- and performance-related research as it demonstrates the positive effects of intensive short exercise interventions. Background and Objectives: Angiogenesis describes the outgrowth of new capillaries from already existing ones. Different biomarkers regulate this process. Physical exercise and hypoxia are key stimuli for the activation of different angiogenic molecules, such as the vascular endothelial growth factor (VEGF). matrix metalloproteases (MMPs)-2 and -9 or the extracellular matrix cleavage fragment endostatin. The present study aimed to investigate influences of short-term, intensive cycling exercise under both normoxic and normobaric hypoxic conditions on the mentioned parameters. Materials and Methods: Twelve male subjects (age: 23.3 ± 2.0 years) participated in the study. All subjects conducted four intensive cycling tests until individual exhaustion in a randomized order under the following conditions: normoxia, 2000 m, 3000 m and 4000 m above sea level. Blood samples were taken before (pre) and 10 min, 30 min, 60 min and 240 min post exercise and were analyzed by ELISA. Results: VEGF showed a significantly reduced concentration compared to the pre-value solely under 4000 m at 10 min post exercise. MMP-2 showed significantly reduced concentrations at 240 min post exercise under 4000 m. MMP-9 increased at 240 min post exercise under both 2000 m and 4000 m conditions. Endostatin was significantly increased at 10 min post exercise independently of the applied stimulus. Conclusions: The presented data show that intensive short-term exercise bouts facilitate the bioavailability of angiogenic, ECM (extracellular matrix)-related biomarkers. This finding is interesting for both health- and performance-related research as it demonstrates the positive effects of intensive short exercise interventions. [ABSTRACT FROM AUTHOR]

The purpose of this study was three-fold: (1) to describe anthropometric, maturation, and somatotype differences of players based on playing positions; (2) to analyze variations of accumulated load training (AcL) and fitness parameters between playing positions; and finally (3) to explain the variation of maximal oxygen uptake (VO2max) and peak power (PP) through the AcL, body fat (BF), maturity, somatotype and fitness levels. Twenty-seven male youth soccer players under-16 were divided by the following positions participated in this study: six central midfielders, four wingers (WG), five forwards, eight defenders, and four goalkeepers (GK). They were evaluated on two occasions: pre-season and after-season. Height, sitting height, body mass, BF, girths, percentage of BF (BF%), lean body mass, maturity, somatotype, sprint test, change of direction test, Yo-Yo intermittent recovery test level 1,Wingate, PP, VO2max and fatigue index were assessed. Then, AcL was monitored during training sessions. The main results revealed significant differences between player positions for maturity offset (p = 0.001), for BF (p = 0.006), BF% (p = 0.015), and lean body mass kg (p = 0.003). Also, there were significant differences for AcL and fatigue index in pre-season between player positions (p < 0.05). In addition, there were some significant differences in pre- and after-season for VO2max and PP between player positions (p < 0.05). In conclusion, GK showed higher values in anthropometric, body composition variables and maturity offset compared to the other positions, while WG presented lower levels of BF. In pre-season, there were more differences by player positions for the different variables analyzed than after-season that reinforces the tactical role of the positions, and the emphasis in increased load in the beginning of the season. This study could be used by coaches, staff, and researchers as a reference for athletes of the same sex, age, and competitive level. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the association between cardiorespiratory fitness and gut microbiota composition in premenopausal women. The participants consisted of 71 premenopausal Finnish women (aged 19-49 years). Gut microbiota were analyzed using flow cytometry, 16S rRNA gene hybridization and DNA-staining. Maximum oxygen uptake (VO2max) was assessed by respiratory gas analyzer and body composition by Bioimpdance. We found that participants with low VO2max had lower Bacteroides, but higher Eubacterium rectale-Clostridium coccoides than the high VO2max group (p < 0.05 for all). VO2max was inversely associated with EreC (r = -0.309, p = 0.01) but not with other bacteria. VO2max also negatively correlated with fat% (r = -0.755, p < 0.001), triglycerides (r = -0.274, p = 0.021) and leptin (r = -0.574, p < 0.001). By contrast, EreC was positively associated with fat% (r = 0.382, p = 0.002), dietary fat intake (r = 0.258, p = 0.034), triglycerides (r = 0.390, p = 0.002) and leptin (r = 0.424, p = 0.001), but negatively with carbohydrate intake (r = -0.252, p = 0.034) and HDL (r = -0.26, p = 0.028). After adjusting for age and dietary intake, all the significant associations remained. However, after adjusting for fat%, the associations between VO2max and EreC disappeared. Our results suggest that cardiorespiratory fitness is associated with gut microbiota composition, independent of age and carbohydrate or fat intake. The association between VO2max and EreC, however, appears to be mediated by body fatness. [ABSTRACT FROM AUTHOR]

Changing medical classification into the functional one in disabled cross-country skiing means that the athlete's predispositions and performance abilities most of all determine the final result in cross-country skiing. Thus, exercise tests have become an indispensable element of the training process. The subject of this study is to present a rare analysis of morpho-functional abilities in relation to the implementation of training workloads during the training preparation for a Paralympic champion in cross-country skiing when she was close to her maximal achievements. The study was performed to investigate abilities evaluated during laboratory tests and how they relate to performance outcomes during major tournaments. An exercise test to exhaustion on a cycle ergometer was performed three times a year on a cross-country disabled female skier over a 10-year period. The morpho-functional level which enabled the athlete to compete for gold medals in the Paralympic Games (PG) is best reflected in the results obtained by her in the tests in the period of direct preparation for the PG and confirms optimal training workloads in this time. The study showed, that the VO 2max level is presently the most important determinant of physical performance achieved by the examined athlete with physical disabilities. The aim of this paper is to present the level of exercise capacity of the Paralympic champion based on the analysis of the results of the tests in relation to the implementation of training workloads.

This paper investigated the effects over time of different forms of neuromuscular training on hemodynamic responses, the estimated VO 2max , and walking performance. 105 older adults were randomly organized into three groups: RG A , RG B , and the Control Group (CG). RG A and RG B did 4 weeks of adaptation phase training and 12 weeks of intervention with different loads: moderate loads for RG B . and higher loads for RG A . A pre- and post-evaluation of the resting heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), double product (DP), estimated VO 2max , and walking performance were assessed. Significant differences were observed for SBP, DBP, HR, and DP. For SBP, a post-evaluation reduction was observed only in RG A ( p = 0.007) and when comparing RG A with the Control Group ( p < 0.000). For the absolute VO 2max, a significant improvement was seen in RG B compared to RG A ( p = 0.037) and CG ( p < 0.000). For the relative VO 2max, RG B scored significantly higher than RG A ( p < 0.000) and CG ( p < 0.000), post-intervention. For the walk test, a significant reduction in completion times was observed for RG A ( p = 0.027) and RG B ( p < 0.000), and for RG B compared to RG A ( p = 0.000) and CG ( p < 0.000). Resistance training can be an excellent strategy for hemodynamic and cardiorespiratory improvement in the elderly.

Cardiorespiratory fitness (CRF) is a core element of healthy physical fitness. Foreign attention to CRF in adolescents at different altitudes is high, while less research has been conducted on Chinese adolescents. In order to compare the CRF of Chinese Tibetan adolescents with their Han counterparts born and raised at high altitude and Chinese Han adolescents at sea level. A total of 2748 participants, including Chinese Tibetan adolescents, Chinese Han adolescents born and raised at high altitudes, and Chinese Han adolescents at sea level aged 12-18 years old, were obtained using convenience sampling and random cluster sampling. The method of the 20 m shuttle run test (20 m SRT) test was used to derive VO 2max by equation. One-way ANOVA and LSD methods were conducted, and effect sizes were calculated to compare the CRF of the three types of adolescents. Regression analysis was used to analyze the relationship between altitude and VO 2max . The VO 2max scores of Chinese Tibetan adolescents and Chinese Han adolescents at sea level were higher than Chinese Han adolescents born and raised at high altitudes. For both boys and girls, the VO 2max scores of Chinese Tibetan adolescents exceeded Chinese Han adolescents at sea level after the age of 16 years old. Regression analysis showed that altitude was inversely associated with VO 2max . The pace of lung growth may distinguish Chinese Tibetan adolescents from Chinese Han adolescents born and raised at high altitudes. The results of the study suggest that we should focus on the changes in CRF in adolescents at different altitudes and should adopt different CRF interventions for adolescents at different altitudes.

Research on the effect of inspiratory muscle training (IMT) on exercise performance is inconsistent. IMT has not been applied to fit child athletes, who are more likely to develop inspiratory muscle fatigue, and, consequently, to benefit from IMT. Methods: Thirty children (mean age: 10.7 ± 1.2 years) were recruited and randomly assigned to a high-intensity (HG), a low-intensity (LG), or a control group (CG). For both training groups, a double-blind procedure was applied. In the HG, 80% of maximal inspiratory pressure (MIP) was used as the level of training intensity. The LG used 30% MIP. Training groups were trained at 6 breaths a set, 4 sets a day, totaling 24 breaths a day for 6 weeks. Exercise capacity outcomes include maximal and submaximal aerobic capacity, as measured as VO 2 max and distance from six-minute walk test (6MWD). Results show improvement in MIP, VO 2 max, and 6MWD only in the HG. MIP in the HG significantly increases from 108.7 (100.8-143.3) to 144.4 (130.0-175.6) cmH 2 O. VO 2 max in the HG increases from 43.0 (40.5-45) to 53.0 (46-63) mL·kg -1 ·min -1 . The 6MWD increases from 792.0 (737.5-818.0) to 862.0 (798.5-953.5) m. Data are presented as median (interquartile range). No difference is found in the LG or CG. Conclusion: high-intensity IMT increases MIP, maximal, and submaximal exercise capacity in the HG, but no difference is found in the LG or CG. Therefore, high-intensity type of IMT improves aerobic fitness in fit children by appropriately applying inspiratory muscle strength training.

The present study aimed to determine the effect of high intensity interval training (HIIT) in hypoxia on maximal oxygen uptake (VO 2max ) compared with HIIT in normoxia with a Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA)-accordant meta-analysis and meta-regression. Studies which measured VO 2max following a minimum of 2 weeks intervention featuring HIIT in hypoxia versus HIIT in normoxia were included. From 119 originally identified titles, nine studies were included ( n = 194 participants). Meta-analysis was conducted on change in (∆) VO 2max using standardised mean difference (SMD) and a random effects model. Meta-regression examined the relationship between the extent of environmental hypoxia (fractional inspired oxygen [FiO 2 ]) and ∆VO 2max and intervention duration and ∆VO 2max . The overall SMD for ∆VO 2max following HIIT in hypoxia was 1.14 (95% CI = 0.56-1.72; p < 0.001). Meta-regressions identified no significant relationship between FiO 2 (coefficient estimate = 0.074, p = 0.852) or intervention duration (coefficient estimate = 0.071, p = 0.423) and ∆VO 2max . In conclusion, HIIT in hypoxia improved VO 2max compared to HIIT in normoxia. Neither extent of hypoxia, nor training duration modified this effect, however the range in FiO 2 was small, which limits interpretation of this meta-regression. Moreover, training duration is not the only training variable known to influence ∆VO 2max , and does not appropriately capture total training stress or load. This meta-analysis provides pooled evidence that HIIT in hypoxia may be more efficacious at improving VO 2max than HIIT in normoxia. The application of these data suggest adding a hypoxic stimuli to a period of HIIT may be more effective at improving VO 2max than HIIT alone. Therefore, coaches and athletes with access to altitude (either natural or simulated) should consider implementing HIIT in hypoxia, rather than HIIT in normoxia where possible, assuming no negative side effects.

Background: Cardiovascular capacity, expressed as maximal oxygen uptake (VO 2max ), is a strong predictor of health and fitness and is considered a key measure of physiological function in the healthy adult population. The purpose of this study was to validate a specific step test (StepTest4all) as an adequate procedure to estimate cardiovascular capacity in young adults., Methods: The sample was composed of 56 participants, including 19 women (aged 21.05 ± 2.39 years, body mass = 57.50 ± 6.64 kg, height = 1.62 ± 0.05 m, body mass index = 22.00 ± 2.92 kg/m 2 ) and 37 men (aged 22.05 ± 3.14 years, body mass = 72.50 ± 7.73 kg, height = 1.76 ± 0.07 m, body mass index = 23.34 ± 2.17 kg/m 2 ). Participants were included in one of the following groups: (i) the group used to predict the VO 2max , and (ii) the group used to validate the prediction model. All participants performed the StepTest4all protocol. The step height and the intensity of the effort was determined individually. Heart rate and oxygen uptake were measured continuously during rest, effort, and recovery phases. The validation process included the following three stages: (i) mean data comparison, (ii) simple linear regression, and (iii) Bland-Altman analysis., Results: The linear regression retained, as significant predictors of the VO 2max , sex ( p < 0.001) and heart rate recovery for one minute ( p = 0.003). The prediction equation revealed a high relationship between measurements (R 2 = 63.0%, SEE = 5.58). The validation procedure revealed non-significant differences ( p > 0.05) between the measured and estimated maximal oxygen uptake, high relationship (R 2 = 63.3%), and high agreement with Bland-Altman plots. Thus, VO 2max can be estimated with the formula: VO 2max = 22 + 0.3 · (HRR 1min ) + 12 · (sex), where HRR 1min is the magnitude of the HR decrease (bpm) in one minute immediately after the step was stopped, and sex: men = 1, women = 0., Conclusions: The StepTest4all is an adequate procedure to estimate cardiovascular capacity, expressed as VO 2max , in young adults. In addition, it is possible to determine the qualitative level of cardiovascular capacity from the heart rate recovery for one minute, more specifically, poor: <20, moderate: 20 to 34, good: 35 to 49, and excellent: ≥50. This procedure has the benefit of being simple to apply and can be used by everyone, even at home, without specialist supervision.