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Concept: VO2 max

407

There is consistent evidence supporting the ergogenic effects of caffeine for endurance based exercise. However, whether caffeine ingested through coffee has the same effects is still subject to debate. The primary aim of the study was to investigate the performance enhancing effects of caffeine and coffee using a time trial performance test, while also investigating the metabolic effects of caffeine and coffee. In a single-blind, crossover, randomised counter-balanced study design, eight trained male cyclists/triathletes (Mean±SD: Age 41±7y, Height 1.80±0.04 m, Weight 78.9±4.1 kg, VO2 max 58±3 ml•kg(-1)•min(-1)) completed 30 min of steady-state (SS) cycling at approximately 55% VO2max followed by a 45 min energy based target time trial (TT). One hour prior to exercise each athlete consumed drinks consisting of caffeine (5 mg CAF/kg BW), instant coffee (5 mg CAF/kg BW), instant decaffeinated coffee or placebo. The set workloads produced similar relative exercise intensities during the SS for all drinks, with no observed difference in carbohydrate or fat oxidation. Performance times during the TT were significantly faster (∼5.0%) for both caffeine and coffee when compared to placebo and decaf (38.35±1.53, 38.27±1.80, 40.23±1.98, 40.31±1.22 min respectively, p<0.05). The significantly faster performance times were similar for both caffeine and coffee. Average power for caffeine and coffee during the TT was significantly greater when compared to placebo and decaf (294±21 W, 291±22 W, 277±14 W, 276±23 W respectively, p<0.05). No significant differences were observed between placebo and decaf during the TT. The present study illustrates that both caffeine (5 mg/kg/BW) and coffee (5 mg/kg/BW) consumed 1 h prior to exercise can improve endurance exercise performance.

Concepts: Time, Coffee, Caffeine, Exercise physiology, VO2 max, Physical fitness, Decaffeination

203

A healthy lifestyle is an important focus in today’s society. The physical benefits of regular exercise are abundantly clear, but physical fitness is also associated with better cognitive performance. How these two factors together relate to characteristics of the brain is still incompletely understood. By applying mathematical concepts from ‘network theory’, insights in the organization and dynamics of brain functioning can be obtained. We test the hypothesis that neural network organization mediates the association between cardio respiratory fitness (i.e. VO2 max) and cognitive functioning. A healthy cohort was studied (n = 219, 113 women, age range 41-44 years). Subjects underwent resting-state eyes-closed magneto-encephalography (MEG). Five artifact-free epochs were analyzed and averaged in six frequency bands (delta-gamma). The phase lag index (PLI) was used as a measure of functional connectivity between all sensors. Modularity analysis was performed, and both within and between-module connectivity of each sensor was calculated. Subjects underwent a maximum oxygen uptake (VO2 max) measurement as an indicator of cardio respiratory fitness. All subjects were tested with a commonly used Dutch intelligence test. Intelligence quotient (IQ) was related to VO2 max. In addition, VO2 max was negatively associated with upper alpha and beta band modularity. Particularly increased intermodular connectivity in the beta band was associated with higher VO2 max and IQ, further indicating a benefit of more global network integration as opposed to local connections. Within-module connectivity showed a spatially varied pattern of correlation, while average connectivity did not show significant results. Mediation analysis was not significant. The occurrence of less modularity in the resting-state is associated with better cardio respiratory fitness, while having increased intermodular connectivity, as opposed to within-module connections, is related to better physical and mental fitness.

Concepts: Brain, Cognition, Intelligence quotient, Exercise physiology, Cooper test, Cardiorespiratory fitness, VO2 max, Physical fitness

189

Recombinant human erythropoietin (rHuEpo) increases haemoglobin mass (Hb(mass)) and maximal oxygen uptake ([Formula: see text] O(2 max)). PURPOSE: This study defined the time course of changes in Hb(mass), [Formula: see text] O(2 max) as well as running time trial performance following 4 weeks of rHuEpo administration to determine whether the laboratory observations would translate into actual improvements in running performance in the field. METHODS: 19 trained men received rHuEpo injections of 50 IU•kg(-1) body mass every two days for 4 weeks. Hb(mass) was determined weekly using the optimized carbon monoxide rebreathing method until 4 weeks after administration. [Formula: see text] O(2 max) and 3,000 m time trial performance were measured pre, post administration and at the end of the study. RESULTS: Relative to baseline, running performance significantly improved by ∼6% after administration (10∶30±1∶07 min:sec vs. 11∶08±1∶15 min:sec, p<0.001) and remained significantly enhanced by ∼3% 4 weeks after administration (10∶46±1∶13 min:sec, p<0.001), while [Formula: see text] O(2 max) was also significantly increased post administration (60.7±5.8 mL•min(-1)•kg(-1) vs. 56.0±6.2 mL•min(-1)•kg(-1), p<0.001) and remained significantly increased 4 weeks after rHuEpo (58.0±5.6 mL•min(-1)•kg(-1), p = 0.021). Hb(mass) was significantly increased at the end of administration compared to baseline (15.2±1.5 g•kg(-1) vs. 12.7±1.2 g•kg(-1), p<0.001). The rate of decrease in Hb(mass) toward baseline values post rHuEpo was similar to that of the increase during administration (-0.53 g•kg(-1)•wk(-1), 95% confidence interval (CI) (-0.68, -0.38) vs. 0.54 g•kg(-1•)wk(-1), CI (0.46, 0.63)) but Hb(mass) was still significantly elevated 4 weeks after administration compared to baseline (13.7±1.1 g•kg(-1), p<0.001). CONCLUSION: Running performance was improved following 4 weeks of rHuEpo and remained elevated 4 weeks after administration compared to baseline. These field performance effects coincided with rHuEpo-induced elevated [Formula: see text] O(2 max) and Hb(mass).

Concepts: Better, Hemoglobin, Oxygen, Erythropoietin, Improve, Carbon monoxide, VO2 max, Knitting

169

BACKGROUND: Aerobic capacity (VO2max) is highly dependent upon body composition of an individual and body composition varies with ethnicity. The purpose of this study was to check the concurrent validity of the non-exercise prediction equation developed by Jackson and colleagues (1990) using percentage body fat as a variable in Asian Indian adults. METHODS: One hundred twenty college-aged participants (60 male, 60 female, mean age 22.02 +/- 2.29 yrs) successfully completed a maximal graded exercise test (GXT) on a motorized treadmill to assess VO2max. VO2max was then estimated by the non-exercise prediction equation developed by Jackson and colleagues (1990) using percentage body fat. Percentage body fat was calculated by three different models (Sandhu et al’s fat mass equation, Durnin-womersley’s 4 site percentage body fat and Jackson & Pollock’s 4 site percentage body fat) and was used in the above equation. The results of VO2max obtained using “gold standard” treadmill methods were then compared with the three results of VO2max obtained by Jackson et al’s equation (using three different models to calculate percentage body fat) and it was determined which equation is best suited to determine percentage body fat and in turn VO2 max for Indian population. RESULTS: Jackson et al’s prediction equation overpredicts VO2max in Asian Indian subjects who have a lower VO2max (33.41 +/- 14.39 ml/kg/min) than those reported in other age matched populations. percentage body fats calculated by the three equations were significantly different and the correlation coefficient ® between VO2max calculated by Jackson and colleagues (1990) using Sandhu et al’s equation for percentage body fat with VO2 max calculated using treadmill (gold standard) (r = .817) was found slightly more significantly correlated than the other two equations and was not statistically different from the measured value. CONCLUSIONS: This study proves that VO2max equation using Sandhu et al’s model for percentage body fat yields more accurate results than other studied equations in healthy college-aged participants in India.

Concepts: Fat, Body fat percentage, Exercise physiology, Cooper test, VO2 max, Physical fitness

50

Economy, velocity/power at maximal oxygen uptake ([Formula: see text]) and endurance-specific muscle power tests (i.e. maximal anaerobic running velocity; vMART), are now thought to be the best performance predictors in elite endurance athletes. In addition to cardiovascular function, these key performance indicators are believed to be partly dictated by the neuromuscular system. One technique to improve neuromuscular efficiency in athletes is through strength training.

Concepts: Oxygen, Binary operation, Exercise physiology, VO2 max, Physical strength

37

Much recent attention has been given to the compatibility of combined aerobic and anaerobic training modalities. However few of these studies have reported data related to well-trained runners, which is a potential limitation. Therefore, due to the limited evidence available for this population, the main aim was to determine which mode of concurrent strength-endurance training might be the most effective at improving running performance in highly-trained runners. Eighteen well-trained male runners (age 23.7± 1.2 yr) with a maximal oxygen consumption (VO2max) higher than 65 mL·kg·min were randomly assigned into one of the three groups: Endurance-only Group (EG; n=6), who continued their usual training, which included general strength training with Thera-band latex-free exercise bands and endurance training; Strength Group (SG; n=6) who performed combined resistance and plyometric exercises and endurance training; Endurance-Strength Group (ESG; n=6) who performed endurance-strength training with loads of 40% and endurance training.. The study comprised 12 weeks of training in which runners trained 8 times a week (6 endurance sessions and 2 strength sessions) and 5 weeks of detraining. The subjects were tested on three different occasions (counter movement jump height, hopping test average height, one-repetition-maximum, running economy, VO2max, maximal heart rate (HRmax), peak velocity, rating of perceived exertion and 3-km time trial were measured). Findings revealed significant time x group interaction effects for all almost tests (p <0.05). We can conclude that concurrent training (CT) for both SG and ESG groups led to improved maximal strength, running economy and peak velocity with no significant effects on the VO2 kinetics pattern. The SG group also seems to show improvements in 3-km time trial tests.

Concepts: Exercise, Exercise physiology, Cooper test, VO2 max, Physical fitness

36

Tracy, BL and Hart, CEF. Bikram yoga training and physical fitness in healthy young adults. J Strength Cond Res 27(3): 822-830, 2013-There has been relatively little longitudinal controlled investigation of the effects of yoga on general physical fitness, despite the widespread participation in this form of exercise. The purpose of this exploratory study was to examine the effect of short-term Bikram yoga training on general physical fitness. Young healthy adults were randomized to yoga training (N = 10, 29 ± 6 years, 24 sessions in 8 weeks) or a control group (N = 11, 26 ± 7 years). Each yoga training session consisted of 90-minute standardized supervised postures performed in a heated and humidified studio. Isometric deadlift strength, handgrip strength, lower back/hamstring and shoulder flexibility, resting heart rate and blood pressure, maximal oxygen consumption (treadmill), and lean and fat mass (dual-energy x-ray absorptiometry) were measured before and after training. Yoga subjects exhibited increased deadlift strength, substantially increased lower back/hamstring flexibility, increased shoulder flexibility, and modestly decreased body fat compared with control group. There were no changes in handgrip strength, cardiovascular measures, or maximal aerobic fitness. In summary, this short-term yoga training protocol produced beneficial changes in musculoskeletal fitness that were specific to the training stimulus.

Concepts: Osteoporosis, Exercise, Strength training, Aerobic exercise, VO2 max, Physical fitness, Bodybuilding, Bikram Yoga

30

This study was designed to examine whether concurrent sprint interval and strength training (CT) would result in compromised strength development when compared to strength training (ST) alone. In addition, maximal oxygen consumption (VO2max) and time to exhaustion (TTE) were measured to determine if sprint interval training (SIT) would augment aerobic performance.

Concepts: Strength training, Exercise physiology, Aerobic exercise, Running, Cooper test, VO2 max, Physical fitness, Interval training

30

Ferley, DD, Osborn, RW, and Vukovich, MD. The effects of uphill vs. level-grade high-intensity interval training on V[Combining Dot Above]O2max, Vmax, VLT, and Tmax in well-trained distance runners. J Strength Cond Res 27(6): 1549-1559, 2013-Uphill running represents a frequently used and often prescribed training tactic in the development of competitive distance runners but remains largely uninvestigated and unsubstantiated as a training modality. The purpose of this investigation included documenting the effects of uphill interval training compared with level-grade interval training on maximal oxygen consumption (V[Combining Dot Above]O2max), the running speed associated with V[Combining Dot Above]O2max (Vmax), the running speed associated with lactate threshold (VLT), and the duration for which Vmax can be sustained (Tmax) in well-trained distance runners. Thirty-two well-trained distance runners (age, 27.4 ± 3.8 years; body mass, 64.8 ± 8.9 kg; height, 173.6 ± 6.4 cm; and V[Combining Dot Above]O2max, 60.9 ± 8.5 ml·min·kg) received assignment to an uphill interval training group (GHill = 12), level-grade interval training group (GFlat = 12), or control group (GCon = 8). GHill and GFlat completed 12 interval and 12 continuous running sessions over 6 weeks, whereas GCon maintained their normal training routine. Pre- and posttest measures of V[Combining Dot Above]O2max, Vmax, VLT, and Tmax were used to assess performance. A 3 × 2 repeated measures analysis of variance was performed for each dependent variable and revealed a significant difference in Tmax in both GHill and GFlat (p < 0.05). With regard to running performance, the results indicate that both uphill and level-grade interval training can induce significant improvements in a run-to-exhaustion test in well-trained runners at the speed associated with V[Combining Dot Above]O2max but that traditional level-grade training produces greater gains.

Concepts: Variance, Analysis of variance, High-intensity interval training, Running, VO2 max, Interval training, Excess post-exercise oxygen consumption, Long slow distance

29

The purpose of this study was to estimate the percentage of the increase in whole body maximal oxygen consumption ([Formula: see text]O(2max)) that is accounted for by increased respiratory muscle oxygen uptake after altitude training. Six elite male distance runners ([Formula: see text]O(2max) = 70.6 ± 4.5 ml kg(-1) min(-1)) and one elite female distance runner ([Formula: see text]O(2max) = 64.7 ml kg(-1) min(-1)) completed a 28-day “live high-train low” training intervention (living elevation, 2,150 m). Before and after altitude training, subjects ran at three submaximal speeds, and during a separate session, performed a graded exercise test to exhaustion. A regression equation derived from published data was used to estimate respiratory muscle [Formula: see text]O(2) ([Formula: see text]O(2RM)) using our ventilation ([Formula: see text] (E)) values. [Formula: see text]O(2RM) was also estimated retrospectively from a larger group of distance runners (n = 22). [Formula: see text]O(2max) significantly (p < 0.05) increased from pre- to post-altitude (196 ± 59 ml min(-1)), while [Formula: see text] (E) at [Formula: see text]O(2max) also significantly (p < 0.05) increased (13.3 ± 5.3 l min(-1)). The estimated [Formula: see text]O(2RM) contributed 37 % of Δ[Formula: see text]O(2max). The retrospective group also saw a significant increase in [Formula: see text]O(2max) from pre- to post-altitude (201 ± 36 ml min(-1)), along with a 10.8 ± 2.1 l min(-1) increase in [Formula: see text] (E), thus requiring an estimated 27 % of Δ[Formula: see text]O(2max). Our data suggest that a substantial portion of the improvement in [Formula: see text]O(2max) with chronic altitude training goes to fuel the respiratory muscles as opposed to the musculature which directly contributes to locomotion. Consequently, the time-course of decay in ventilatory acclimatization following return to sea-level may have an impact on competitive performance.

Concepts: Statistics, Muscle, Respiratory system, Exercise physiology, Altitude sickness, VO2 max, Acclimatization, Effects of high altitude on humans