Determinants Of Endurance Performance Research Articles

The effect of a 4-week, remotely administered, post-exercise passive leg heating intervention on determinants of endurance performance.

Post-exercise passive heating has been reported to augment adaptations associated with endurance training. The current study evaluated the effect of a 4-week remotely administered, post-exercise passive leg heating protocol, using an electrically heated layering ensemble, on determinants of endurance performance. Thirty recreationally trained participants were randomly allocated to either a post-exercise passive leg heating (PAH, n = 16) or unsupervised training only control group (CON, n = 14). The PAH group wore the passive heating ensemble for 90-120min/day, completing a total of 20 (16 post-exercise and 4 stand-alone leg heating) sessions across 4weeks. Whole-body (peak oxygen uptake, gas exchange threshold, gross efficiency and pulmonary oxygen uptake kinetics), single-leg exercise (critical torque and NIRS-derived muscle oxygenation), resting vascular characteristics (flow-mediated dilation) and angiogenic blood measures (nitrate, vascular endothelial growth factor and hypoxia inducible factor 1-α) were recorded to characterize the endurance phenotype. All measures were assessed before (PRE), at 2weeks (MID) and after (POST) the intervention. There was no effect of the intervention on test of whole-body endurance capacity, vascular function or blood markers (p > 0.05). However, oxygen kinetics were adversely affected by PAH, denoted by a slowing of the phase II time constant; τ (p = 0.02). Furthermore, critical torque-deoxygenation ratio was improved in CON relative to PAH (p = 0.03). We have demonstrated that PAH had no ergogenic benefit but instead elicited some unfavourable effects on sub-maximal exercise characteristics in recreationally trained individuals.

The Record Power Profile of Male Professional Cyclists: Fatigue Matters.

The present study aimed to determine the influence of fatigue on the record power profile of professional male cyclists. We also assessed whether fatigue could differently affect cyclists of 2 competition categories. We analyzed the record power profile in 112 professional cyclists (n = 46 and n = 66 in the ProTeam [PT] and WorldTour [WT] category, respectively; age 29 [6]y, 8 [5]y experience in the professional category) during 2013-2021 (8 [5] seasons/cyclist). We analyzed their mean maximal power (MMP) values for efforts lasting 10 seconds to 120minutes with no fatigue (after 0kJ·kg-1) and with increasing levels of fatigue (after 15, 25, 35, and 45kJ·kg-1). A significant (P < .001) and progressive deterioration of all MMP values was observed from the lowest levels of fatigue assessed (ie,-1.6% to -3.0% decline after 15kJ·kg-1, and -6.0% to -9.7% after 45kJ·kg-1). Compared with WT, PT cyclists showed a greater decay of MMP values under fatigue conditions (P < .001), and these differences increased with accumulating levels of fatigue (decay of -1.8 to -2.9% [WT] with reference to 0kJ·kg-1 vs -1.1% to -4.4% [PT] after 15kJ·kg-1 and of -4.7% to -8.8% [WT] vs -7.6% to -11.6% [PT] after 45kJ·kg-1). No consistent differences were found between WT and PT cyclists in MMP values assessed in nonfatigue conditions (after 0kJ·kg-1), but WT cyclists attained significantly higher MMP values with accumulating levels of fatigue, particularly for long-duration efforts (≥5min). Our findings highlight the importance of considering fatigue when assessing the record power profile of endurance athletes and support the ability to attenuate fatigue-induced decline in MMP values as a determinant of endurance performance.

Defining the determinants of endurance running performance in the heat

ABSTRACTIn cool conditions, physiologic markers accurately predict endurance performance, but it is unclear whether thermal strain and perceived thermal strain modify the strength of these relationships. This study examined the relationships between traditional determinants of endurance performance and time to complete a 5-km time trial in the heat. Seventeen club runners completed graded exercise tests (GXT) in hot (GXTHOT; 32°C, 60% RH, 27.2°C WBGT) and cool conditions (GXTCOOL; 13°C, 50% RH, 9.3°C WBGT) to determine maximal oxygen uptake (V̇O2max), running economy (RE), velocity at V̇O2max (vV̇O2max), and running speeds corresponding to the lactate threshold (LT, 2 mmol.l−1) and lactate turnpoint (LTP, 4 mmol.l−1). Simultaneous multiple linear regression was used to predict 5 km time, using these determinants, indicating neither GXTHOT (R2 = 0.72) nor GXTCOOL (R2 = 0.86) predicted performance in the heat as strongly has previously been reported in cool conditions. vV̇O2max was the strongest individual predictor of performance, both when assessed in GXTHOT (r = −0.83) and GXTCOOL (r = −0.90). The GXTs revealed the following correlations for individual predictors in GXTHOT; V̇O2max r = −0.7, RE r = 0.36, LT r = −0.77, LTP r = −0.78 and in GXTCOOL; V̇O2max r = −0.67, RE r = 0.62, LT r = −0.79, LTP r = −0.8. These data indicate (i) GXTHOT does not predict 5 km running performance in the heat as strongly as a GXTCOOL, (ii) as in cool conditions, vV̇O2max may best predict running performance in the heat.

Effects of submaximal and supramaximal interval training on determinants of endurance performance in endurance athletes.

We compared the effects of submaximal and supramaximal cycling interval training on determinants of exercise performance in moderately endurance-trained men. Maximal oxygen consumption (VO2max ), peak power output (Ppeak ), and peak and mean anaerobic power were measured before and after 6weeks (3 sessions/week) of submaximal (85% maximal aerobic power [MP], HIIT85 , n=8) or supramaximal (115% MP, HIIT115 , n=9) interval training to exhaustion in moderately endurance-trained men. High-intensity training volume was 47% lower in HIIT115 vs HIIT85 (304±77 vs 571±200min; P<0.01). Exercise training was generally associated with increased VO2max (HIIT85 : +3.3±3.1mL/kg/min; HIIT115 : +3.3±3.6ml/kg/min; Time effect P=0.002; Group effect: P=0.95), Ppeak (HIIT85 : +18±9W; HIIT115 : +16±27W; Time effect P=0.045; Group effect: P=0.49), and mean anaerobic power (HIIT85 : +0.42±0.69W/kg; HIIT115 : +0.55±0.65W/kg; Time effect P=0.01; Group effect: P=0.18). Six weeks of submaximal and supramaximal interval training performed to exhaustion seems to equally improve VO2max and anaerobic power in endurance-trained men, despite half the accumulated time spent at the target intensity.

Thresholds in ventilation, cerebral and muscle oxygenation, and muscle activity during incremental cycling exercise

Introduction: Cycle time-trial performance is a function of the highest sustainable power output. The first (VT-1) and second (VT-2) ventilatory thresholds are practical tools for coaches and athletes to set training zones and exercise intensity. Specifically, VT-2 is closely linked to critical power, a primary determinant of endurance performance. The cascade of physiological events in the organs responsible for power production accompanying these respiratory thresholds remains contentious and yet to be fully characterized. Electromyographic (EMG) thresholds have been identified in leg muscles during incremental exercise while near infrared spectroscopy (NIRS) has revealed thresholds in both muscle deoxygenation and cerebral oxygenation towards the end of an incremental exercise test. However, the relative timing of the different muscle and brain oxygenation and muscle electrical activity responses to each other is unclear. Purpose: The aim of the present study was to examine the thresholds of cerebral and muscle oxygenation, along with muscle electrical activity during a ramp exercise test in relation to VT-1 and VT-2. Methods: Twenty-five recreational cyclists (mean±SD: age 37±8yrs, body mass 78±13kg, height 178±8cm, VO 2 max 53±8mL/kg/min) completed a ramp exercise test to exhaustion on an electromagnetically braked cycle-ergometer with a work rate increment of 25 W/min. Throughout the test, continuous measures of expired gas (breath-by-breath), prefrontal cortex and vastus lateralis (VL) oxygenation via NIRS, and EMG Root Mean Square activity for the VL, rectus femoris (RF), and biceps femoris (BF) muscles were recorded. Thresholds were defined by a double-linear model. Results: The results are summarized in Figure 1. VT-1 and VT-2 occurred at 57 ± 6% and 81 ± 6% of the exercise, respectively. There was a threshold in both cerebral deoxyhaemoglobin and oxyhaemoglobin (56±13% and 56±8% of exercise, respectively) which were not significantly different from VT-1 ( P >0.86, cohens d 0.8). Only one threshold could be identified for muscle parameters with a threshold in muscle oxyhaemoglobin (78±9% of exercise), attenuation in muscle deoxyhaemoglobin (80±8% of exercise), and increase in EMG activity of VL, RF and BF (89±5%, 82±14% and 85±9% of exercise, respectively). The thresholds in BF and VL EMG activity occurred after VT-2 ( P 0.6). Conclusion: The threshold in cerebral oxygenation parameters occurred at both VT-1 and VT-2. Conversely, the present investigation failed to support a role for VL muscle oxygenation and electrical activity at VT-1, but did display a threshold at or after VT-2. The changes in cerebral oxygenation and in BF and VL electrical activity occurred after VT-2, suggesting that the metabolic and ventilatory events characterizing this latter cardiorespiratory threshold may affect both cerebral and muscle oxygenation levels and subsequent muscle recruitment responses. These physiological mechanisms are important factors in describing key training concepts and performance capability; for instance critical power. Any marked rise in muscle recruitment above VT-2 or critical power will result in early onset of fatigue and limit exercise performance.

Treadmill-based cycling time trial better predicts seasonal cross-country mountain bike performance than traditional parameters in laboratory tests

Specific cross-country mountain bike (MTB) laboratory tests are used to monitor training and performance of elite athletes. To better follow up long-term performance development we designed a new MTB specific treadmill-based cycling time trial. The purpose of this study was to investigate the relationship between different physiological parameters from this new test as well as from traditional laboratory tests and overall MTB performance in the following season. Thirteen male cyclists (24.1 ± 3.6 y; 175.9 ± 5.1 cm; 68.1 ± 4.0 kg; 606 ± 589 UCI points) of the Swiss National MTB Team completed three laboratory tests to exhaustion within two days. On the first day, the athletes performed two tests on an SRM cycle ergometer: 1) a long graded exercise test (LGXT) (workload increased 30 W/5 min) to determine the lactate threshold (LT1), the Dmod threshold (Bishop et al., 1998: Medicine & Science in Sports & Exercise, 30(8), 1270–1275), and peak power output (PPOLGXT); and 2) a short graded exercise test (SGXT) (workload increased 25 W/min) to determine maximal oxygen uptake (VI‡O2max) and peak power output (PPOSGXT). On the second day, the athletes performed a MTB-specific 24-min time trial (TT) with variable inclination (4 - 10°) on a motorized treadmill (3x4.5 m) using their own bikes. The athletes were instructed to ride at a self-selected maximal pace and the total distance covered in 24 min was used as the performance measure. All performance-based parameters are expressed relative to body mass. The season performance was evaluated using the International Cycling Union (UCI) points. Pearson correlation analysis was applied to determine the relationship between physiological parameters and the UCI points. The UCI points correlated significantly with TT distance, PPOLGXT and Dmod (r = 0.83, p = 0.001; r = 0.76, p = 0.003 and r = 0.67, p = 0.012). No significant correlation was observed between VI‡O2max, PPOSGXT and LT1 and the UCI points (r = 0.41, p = 0.144; r = 0.49, p = 0.077 and r = 0.51, p = 0.077). The current test battery indicates that TT distance is the best correlate of seasonal MTB performance, with TT distance explaining 68% of the observed variance in UCI points. Furthermore, high UCI rankings were also highly correlated with PPOLGXT and the related Dmod during the LGXT. In contrast VI‡O2max, traditionally regarded as an important determinant of endurance performance (Coyle et al., 1988: Journal of Applied Physiology, 64, 2622–2630), and PPOSGXT, did not show a significant correlation with UCI points in this group of athletes. In accordance with these findings, we observed that younger athletes often achieved comparable values as elite athletes in the SGXT, suggesting the performance difference (UCI points) is differentiated only by the distance completed in the treadmill-based cycling TT. It appears that graded exercise tests of a short duration do not adequately represent the duration that a given workload can be sustained. Therefore for a comprehensive MTB-specific laboratory test battery, we suggest including a MTB-specific time trial with a constant test duration to predict seasonal MTB performance.

Effect of Long-Term Oral Contraceptive Use on Determinants of Endurance Performance

We examined the effect of long-term oral contraceptive (OC) use on endurance performance in recreationally active women. Eight women using OC (OC group) and 8 women who were nonusers (CON group) performed a test to determine the peak oxygen uptake for cycling (V[Combining Dot Above]O2peak) and to estimate the anaerobic threshold (AT). Subjects also completed a continuous submaximal cycling test across 3 work stages (two 6-minute work stages below AT, and 1 above AT performed to exhaustion). Pulmonary gas exchange, heart rate (HR), blood pressure (BP), blood lactate concentration ([La]), and ratings of perceived exertion were measured throughout, and cycling economy was calculated. Physical characteristics were comparable between the groups (p > 0.05). Peak oxygen uptake (CON group: 2.59 ± 0.50 L·min; OC group: 2.13 ± 0.20 L·min) and oxygen uptake at the AT (CON group: 1.47 ± 0.27 L·min; OC group: 1.18 ± 0.15 L·min) were significantly different (p < 0.05) between the groups. Expired minute ventilation, HR, BP, [La], and cycling economy for all constant-load work stages were not significantly different (p > 0.05) between the groups. Furthermore, time to exhaustion for severe-intensity cycling was similar (p > 0.05) between the CON and OC groups. The results of the present study suggest that long-term OC use negatively affects peak V[Combining Dot Above]O2 and V[Combining Dot Above]O2 at the AT but does not alter endurance exercise performance.

ACTN3 R577X and other polymorphisms are not associated with elite endurance athlete status in the Genathlete study

Homozygosity for a premature stop codon at amino acid position 577 in the alpha-actinin-3 (ACTN3) gene leads to α-actinin-3 deficiency. This genotype is observed in approximately 18% of Caucasians. The ACTN3 R577X polymorphism has been previously associated with indicators of physical performance in several, but not all, studies. We examined the prevalence of R577X (rs1815739) and two additional haplotype tagging single nucleotide polymorphisms (htSNPs) of the ACTN3 gene (rs1791690 and rs2275998) in the Genathlete study comprising 316 male elite endurance athletes ([Vdot]O2max 79.0 ± 3.5 ml · kg−1 · min−1; mean ± s) from North America, Finland, and Germany and 304 sedentary controls ([Vdot]O2max 40.1 ± 7.0 ml · kg−1 · min−1) matched by country of origin. The distribution of genotype and allele frequencies between the two groups was tested by Pearson chi-square and/or Fischer exact test. The prevalence of the 577X homozygote genotype was similar in endurance athletes and controls (20% and 17.5%, respectively). The resulting odds ratio for endurance performance in 577X homozygotes compared with 577R-allele carriers was 1.24 (95%CI 0.82–1.87, P = 0.3). The genotype distribution of the two htSNPs and haplotype frequencies did not differ significantly between athletes and controls. In conclusion, our findings indicate that ACTN3 R577X and other SNPs in ACTN3 are not genetic determinants of endurance performance in Caucasian males.

Lactate threshold responses to a season of professional British youth soccer

Objective: To examine the changes in aerobic endurance performance of professional youth soccer players throughout the soccer season. Methods: Nine youth soccer players were tested at six different time points...

운동의 분자생물학적 탐색

The purpose of study to phenomenological examine and the mechanism regarding the gene(DNA, RNA, Protein) and sports to studied, analyzed, and evaluated. This review considers the evidence for genetic effects in several determinants of endurance performance and resistance performance, namely : body measurements and physique, body fat pulmonary functions, cardiac and circulatory functions, muscle characteristics, substrate utilization, maximal aerobic power and other. Moreover, the response to aerobic training of indicators aerobic work metabolism and endurance performance is reviewed, with emphasis on the specificity of the response and the individual differences observed in training ability. This study indicate that improvement of `Enhancer Action` in RNA genes changed by exercise or sports. Moreover exercise was effect on Central Dogma with DNA makes RNA makes Protein. and think that occurred with exercise influence on skeletal muscle into cell have to Myosin Heavy Chain(MHC) changed was after exercise performance, which accompanied into skeletal muscle that were exercise-induces gene-modulation that is, take gene mutations. This study known that existed hormone(epinephrine)-immune system with interaction. Exercise were altered insulin binding and MAP Kinase signaling increased into immune cells. This review suggested that the high rate of glutamine utilization by cells of the immune system serves to maintain a high intra cellular concentration of the intermediates of biosynthetic pathways such that optimal rates of DNA, RNA and protein synthesis can be maintained. In the absence of glutamine, lymphocytes do not proliferate in vitro; proliferation increase greatly as the glutamine concentration increase. Glutamine is synthesized in skeletal muscle. Skeletal muscle and plasma glutamine levels are lowered by sepsis, injury, bums, surgery and endurance exercise and in the overtrained athlete. The study of result show that production of ET-1 is markedly increased tissue specifically in the heart by exercise without appreciable changes in endothelin-converting enzyme and endothelial receptor expressions, suggest that myocardial ET-1 may participate in modulation of cardiac function during exercise. Conclusionally, this study indicate that improvement of `Enhancer Action` in RNA genes changed by exercise or sports. Moreover exercise was effect on Central Dogma with DNA makes RNA makes Protein. This study is expected to contribute the area of sports science, medicine, hereafter more effort is required to establish the relation between gene alters and exercise amount.

Limiting factors for maximum oxygen uptake and determinants of endurance performance.

In the exercising human, maximal oxygen uptake (VO2max) is limited by the ability of the cardiorespiratory system to deliver oxygen to the exercising muscles. This is shown by three major lines of evidence: 1) when oxygen delivery is altered (by blood doping, hypoxia, or beta-blockade), VO2max changes accordingly; 2) the increase in VO2max with training results primarily from an increase in maximal cardiac output (not an increase in the a-v O2 difference); and 3) when a small muscle mass is overperfused during exercise, it has an extremely high capacity for consuming oxygen. Thus, O2 delivery, not skeletal muscle O2 extraction, is viewed as the primary limiting factor for VO2max in exercising humans. Metabolic adaptations in skeletal muscle are, however, critical for improving submaximal endurance performance. Endurance training causes an increase in mitochondrial enzyme activities, which improves performance by enhancing fat oxidation and decreasing lactic acid accumulation at a given VO2. VO2max is an important variable that sets the upper limit for endurance performance (an athlete cannot operate above 100% VO2max, for extended periods). Running economy and fractional utilization of VO2max also affect endurance performance. The speed at lactate threshold (LT) integrates all three of these variables and is the best physiological predictor of distance running performance.

Aerobic, Anaerobic and Isokinetic Measures of Elite Canadian Male and Female Speed Skaters

This study was conducted to evaluate the physiological parameters of elite speed skaters after a period of summer training, and to examine the relationships between these measures and speed skating performance. The subjects were eight male and eight female members of the Canadian National Speed Skating Team. The tests performed included assessment of body composition, aerobic power, anaerobic power and isokinetic peak torque measures for knee and hip flexion/extension and hip abduction/adduction. Mean values obtained for JOURNAL/jscr/beta/00124278-199108000-00001/ENTITY_OV0312/v/2017-05-04T192841Z/r/image-pngO2 max were 61.9 ± 2.7 and 53.5 ± 2.0 ml·kg−1·min−1 for male and female skaters, respectively. Male sprinters were found to have significantly higher five-second peak anaerobic power than all-around skaters (16.6 ± 0.9 versus 14.4 ± 1.1 W·kg−1 of body weight). Anaerobic five-second peak power was significantly correlated with both relative knee extension at 180°·sec−1 for male skaters (r = 0.78) and 500-meter velocity (r = 0.81). These results demonstrate a relationship between laboratory measures and sprint speed skating performance. However, because JOURNAL/jscr/beta/00124278-199108000-00001/ENTITY_OV0312/v/2017-05-04T192841Z/r/image-pngO2 max was unrelated to distance performance, further research is required to determine the underlying determinants of endurance performance in speed skating.

Heredity and Endurance Performance

Performance in endurance sports is affected by a variety of factors, including exercise-training habits, nutrition and other lifestyle components. Endurance performance can also be seen as a multifactorial phenotype influenced by genetic and non-genetic factors. Current models in quantitative genetics and experimental data available in the sport sciences literature suggest that the effects of genetic variation on endurance performance can be observed as (a) the consequence of a character highly determined by the genotype which is correlated with endurance performance, (b) inherited differences in endurance performance exhibited by individuals of a sample or population, and (c) genotype-dependent individual differences in the response to endurance training. This review considers the evidence for genetic effects in several determinants of endurance performance, namely: body measurements and physique, body fat, pulmonary functions, cardiac and circulatory functions, muscle characteristics, substrate utilisation, maximal aerobic power and others. Moreover, the response to aerobic training of indicators of aerobic work metabolism and endurance performance is reviewed, with emphasis on the specificity of the response and the individual differences observed in trainability. It is concluded that there are considerable interindividual differences in the level of endowment for endurance performance. This genetic effect remains, however, quite modest when compared with other phenotypes, such as the skeletal dimensions of the body. Moreover, while trainability of the capacity for endurance performance is quite high on the average, there are important individual differences in the sensitivity to endurance training. Recent data suggest that this sensitivity to aerobic training is largely genotype-dependent.