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Sara López-Martínez, Mairena Sánchez-López, Montserrat Solera-Martinez, Natalia Arias-Palencia, Rosa M. Fuentes-Chacón and Vicente Martínez-Vizcaíno

Purpose:

Our objective was to analyze the association between different intensities of physical activity (PA), physical fitness, and metabolic syndrome (MS) in young adults.

Methods:

Cross-sectional study including 275 university students, 18–30 years old, from Cuenca, Spain. We evaluated (a) physical activity using accelerometry, (b) aerobic capacity (VO2max), and (c) muscle strength, by a muscle strength index calculated as the sum of the standardized z score of handgrip dynamometry/weight and standing broad jump. An MS index was estimated by summing standardized z scores of waist circumference, ratio of triglycerides to high-density lipoprotein, mean arterial blood pressure, and HOMA-IR.

Results:

The mean scores of MS index and HOMAIR were significantly higher and the VO2max significantly lower for individuals who did not perform 20 min or more per week of vigorous physical activity. However, those who performed 250 min/week of moderate physical activity showed no significant differences in either VO2max or the MS index when compared with individuals who did not perform this level of activity. The MS index was lower in those with medium-high levels of aerobic capacity. In addition, individuals with medium-high levels of muscular fitness showed lower waist circumference and a lower MS index.

Conclusions:

VO2max and muscle strength are negatively associated with metabolic risk. 20-min/week of vigorous physical activity was associated with lower cardiometabolic risk in young adults; moderate physical activity did not show association with lower cardiometabolic risk.

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Ine Wigernæs, Sigmund B. Strømme and Arne T. Høstmark

The present study investigated the effect of active recovery (AR) as compared to rest recovery (RR) upon FFA concentrations following moderate- (MI) or high-intensity (HI) running. Fourteen well-trained males (23.7±6 years. V̇O2max = 69.5±1.8ml · min−1kg−1) were randomly assigned into two trials (HI = 30 min at 82% of V̇O2max; MI = 60 min at 75% of V̇O2max). Within each group, the subject completed two sets of experiments of running followed by either AR (15 min running at 50% of V̇O2max) or RR (complete rest in the supine position). Plasma volume changes after the exercise did not deviate between the AR or RR trials. In both the HI and Ml trials, AR resulted in lower FFA peaks and lower overall FFA concentrations while performing AR (p<.05). However, upon discontinuing AR. there was a rise in the FFA concentration. At 120-min post-exercise, the FFA concentrations after AR and RR were not significantly different. The changes in the FFA/albumin ratio were similar to the FFA responses. It is concluded that AR may counteract the rise in FFA 5–15 minutes after exercise.

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Jack M. Burns, Jeremiah J. Peiffer, Chris R. Abbiss, Greig Watson, Angus Burnett and Paul B. Laursen

Purpose:

Manufacturers of uncoupled cycling cranks claim that their use will increase economy of motion and gross efficiency. Purportedly, this occurs by altering the muscle-recruitment patterns contributing to the resistive forces occurring during the recovery phase of the pedal stroke. Uncoupled cranks use an independent-clutch design by which each leg cycles independently of the other (ie, the cranks are not fixed together). However, research examining the efficacy of training with uncoupled cranks is equivocal. The purpose of this study was to determine the effect of short-term training with uncoupled cranks on the performance-related variables economy of motion, gross efficiency, maximal oxygen uptake (VO2max), and muscle-activation patterns.

Methods:

Sixteen trained cyclists were matched-paired into either an uncoupled-crank or a normal-crank training group. Both groups performed 5 wk of training on their assigned cranks. Before and after training, participants completed a graded exercise test using normal cranks. Expired gases were collected to determine economy of motion, gross efficiency, and VO2max, while integrated electromyography (iEMG) was used to examine muscle-activation patterns of the vastus lateralis, biceps femoris, and gastrocnemius.

Results:

No significant changes between groups were observed for economy of motion, gross efficiency, VO2max, or iEMG in the uncoupled- or normal-crank group.

Conclusions:

Five weeks of training with uncoupled cycling cranks had no effect on economy of motion, gross efficiency, muscle recruitment, or VO2max compared with training on normal cranks.

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Amy Warren, Erin J. Howden, Andrew D. Williams, James W. Fell and Nathan A. Johnson

Postexercise fat oxidation may be important for exercise prescription aimed at optimizing fat loss. The authors examined the effects of exercise intensity, duration, and modality on postexercise oxygen consumption (VO2) and substrate selection/respiratory-exchange ratio (RER) in healthy individuals. Three experiments (n = 7 for each) compared (a) short- (SD) vs. long-duration (LD) ergometer cycling exercise (30 min vs. 90 min) matched for intensity, (b) low- (LI) vs. high-intensity (HI) cycling (50% vs. 85% of VO2max) matched for energy expenditure, and (c) continuous (CON) vs. interval (INT) cycling matched for energy expenditure and mean intensity. All experiments were administered by crossover design. Altering exercise duration did not affect postexercise VO2 or RER kinetics (p > .05). However, RER was lower and fat oxidation was higher during the postexercise period in LD vs. SD (p < .05). HI vs. LI resulted in a significant increase in total postexercise energy expenditure and fat oxidation (p < .01). Altering exercise modality (CON vs. INT) did not affect postexercise VO2, RER, or fat oxidation (p > .05). These results demonstrate that postexercise energy expenditure and fat oxidation can be augmented by increasing exercise intensity, but these benefits cannot be exploited by undertaking interval exercise (1:2-min work:recovery ratio) when total energy expenditure, duration, and mean intensity remain unchanged. In spite of the apparent benefit of these strategies, the amount of fat oxidized after exercise may be inconsequential compared with that oxidized during the exercise bout.

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Marcus P. Tartaruga, Carlos B. Mota, Leonardo A. Peyré-Tartaruga and Jeanick Brisswalter

Purpose:

To identify the effect of allometric scaling on the relationship between running efficiency (R Eff) and middle-distancerunning performance according to performance level.

Methods:

Thirteen male recreational middle-distance runners (mean ± SD age 33.3 ± 8.4 y, body mass 76.4 ± 8.6 kg, maximal oxygen uptake [VO2max] 52.8 ± 4.6 mL · kg−1 · min−1; G1) and 13 male high-level middle-distance runners (age 25.5 ± 4.2 y, body mass 62.8 ± 2.7 kg, VO2max 70.4 ± 1.9 mL · kg−1 · min−1; G2) performed a continuous incremental test to volitional exhaustion to determine VO2max and a 6-min submaximal running test at 70% of VO2max to assess R Eff.

Results:

Significant correlation between R Eff and performance were found for both groups; however, the strongest correlations were observed in recreational runners, especially when using the allometric exponent (respectively for G1, nonallometric vs allometric scaling: r = .80 vs r = .86; and for G2, nonallometric vs allometric scaling: r = .55 vs r = .50).

Conclusion:

These results indicate that an allometric normalization may improve endurance-performance prediction from R Eff values in recreational, but not in elite, runners.

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Ville Vesterinen, Ari Nummela, Sami Äyrämö, Tanja Laine, Esa Hynynen, Jussi Mikkola and Keijo Häkkinen

Regular monitoring of adaptation to training is important for optimizing training load and recovery, which is the main factor in successful training.

Purpose:

To investigate the usefulness of a novel submaximal running test (SRT) in field conditions in predicting and tracking changes of endurance performance.

Methods:

Thirty-five endurance-trained men and women (age 20–55 y) completed the 18-wk endurance-training program. A maximal incremental running test was performed at weeks 0, 9, and 18 for determination of maximal oxygen consumption (VO2max) and running speed (RS) at exhaustion (RSpeak) and lactate thresholds (LTs). In addition, the subjects performed weekly a 3-stage SRT including a postexercise heart-rate-recovery (HRR) measurement. The subjects were retrospectively grouped into 4 clusters according to changes in SRT results.

Results:

Large correlations (r = .60–.89) were observed between RS during all stages of SRT and all endurance-performance variables (VO2max, RSpeak, RS at LT2, and RS at LT1). HRR correlated only with VO2max (r = .46). Large relationships were also found between changes in RS during 80% and 90% HRmax stages of SRT and a change of RSpeak (r = .57, r = .79). In addition, the cluster analysis revealed the different trends in RS during 80% and 90% stages during the training between the clusters, which showed different improvements in VO2max and RSpeak.

Conclusions:

The current SRT showed great potential as a practical tool for regular monitoring of individual adaptation to endurance training without time-consuming and expensive laboratory tests.

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Cory W. Baumann, Jeffrey C. Rupp, Christopher P. Ingalls and J. Andrew Doyle

Purpose:

The purpose of this study was to examine the relationship between anaerobic characteristics and 5-km-race performance in trained female cross-country runners (N = 13).

Methods:

The runners performed 50-m sprints and a 5-km time trial on an outdoor 400-m track and maximal anaerobic (MART) and aerobic running tests on a motorized treadmill. Anaerobic characteristics were determined by the mean velocity of the 50-m sprint (v 50m) and the peak velocity in the MART (v MART). The aerobic characteristics were obtained during the aerobic treadmill test and included maximal oxygen uptake (VO2max), running economy, and ventilatory threshold (VT).

Results:

Both the v MART (r = .69, P < .01) and VO2max (r = .80, P < .01) correlated with the mean velocity of the 5-km (v 5km). A multiple-linear-regression analysis revealed that the combination of VO2max, v MART, and VT explained 81% (R 2 = .81, P < .001) of the variation seen in the v 5km. The v MART accounted for 31% of the total shared variance, while the combination of VO2max and VT explained the remaining 50%.

Conclusions:

These results suggest that among trained female runners who are relatively matched, anaerobic energy production can effectively discriminate the v 5km and explain a significant amount of the variation seen in 5-km-race performance.

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Allen C. Parcell, Jason M. Smith, Shane S. Schulthies, J. William Myrer and Gilbert Fellingham

It is purported that supplementation with Cordyceps Sinensis (CordyMax Cs-4) will improve oxidative capacity and endurance performance. The intent of this investigation was to examine the effects of CordyMax Cs-4 supplementation on VO2peak, ventilatory threshold, and endurance performance in endurance-trained cyclists. Twenty-two male cyclists participated in 5 weeks of supplementation with CordyMax Cs-4 tablets (3 g/d). Training intensity was maintained by weekly documentation and reporting throughout the 5-week period. Subjects completed a VO2peak test and work-based time trial prior to and following the supplementation period. VO2peak was similar within and between placebo (PLA) and treatment (CS) groups prior to (59.9 ± 5.9 vs. 59.1 ± 5.4 ml/kg/min, respectively) and following (60.1 ± 5.5 vs. 57.1 ± 5.8 ml/kg/min, respectively) the supplementation period. Ventilatory threshold (VT) was measured at 72 ± 10% of VO2peak in P and T prior to supplementation and did not change in either group following the supplementation. PLA completed the time trial in 61.4 ± 2.4 min compared to 62.1 ± 4.0 min in T. Time trial measurements did not differ between groups, nor did they change in response to supplementation. It is concluded that 5 weeks of CordyMax Cs-4 supplementation has no effect on aerobic capacity or endurance exercise performance in endurance-trained male cyclists.

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William McGarvey, Richard Jones and Stewart Petersen

The purpose of this investigation was to examine the effect of interval (INT) and continuous (CON) cycle exercise on excess post-exercise oxygen consumption (EPOC). Twelve males first completed a graded exercise test for VO2max and then the two exercise challenges in random order on separate days approximately 1 wk apart. The INT challenge consisted of seven 2 min work intervals at 90% VO2max, each followed by 3 min of relief at 30% VO2max. The CON exercise consisted of 30 to 32 min of continuous cycling at 65% VO2max. Gas exchange and heart rate (HR) were measured for 30 min before, during, and for 2 h post-exercise. Three methods were used to analyze post-exercise oxygen consumption and all produced similar results. There were no significant differences in either the magnitude or duration of EPOC between the CON and INT protocols. HR, however, was higher (P < 0.05) while respiratory exchange ratio (RER) was lower (P < 0.05) following INT. These results indicate that when total work was similar, the magnitude and duration of EPOC were similar following CON or INT exercise. The differences in HR and RER during recovery suggest differential physiological responses to the exercise challenges.

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Michail Lubomirov Michailov, Audry Morrison, Mano Mitkov Ketenliev and Boyanka Petkova Pentcheva

Traditional treadmill or bicycle ergometry neglects the upper-body musculature that predominantly limits or terminates rock-climbing performance (ie, the inability to continually pull up one’s body mass or “hang on”).

Purpose:

To develop an incremental maximal upper-body ergometer test (UBT) to evaluate climbers’ aerobic fitness and sport-specific work capacity and to compare these results with a traditional treadmill protocol.

Methods:

Eleven elite sport climbers (best redpoint grade Fr.8b) performed a UBT on a vertically mounted rowing ergometer and, on a separate occasion, performed a maximal incremental treadmill test (TMT). Cardiorespiratory parameters were measured continuously. Lactate (La) samples were collected.

Results:

Peak oxygen consumption (VO2peak) and heart rate in UBT and TMT were 34.1 ± 4.1 vs 58.3 ± 2.6 mL · min−1 · kg−1 and 185 ± 8 vs 197 ± 8 beats/min, respectively, and both variables were of significantly lower magnitude during UBT (P < .001). End-of-test La levels for UBT (11.9 ± 1.7 mmol/L) and TMT (12.3 ± 2.5 mmol/L) were similar (P = .554). Treadmill VO2peak was not correlated with either upper-body (UB) VO2peak (P = .854) or redpoint and on-sight climbing grade ability (P > .05). UB VO2peak and peak power output per kg body mass were both strongly correlated (P < .05) with climbing grade ability. The highest correlation coefficient was calculated between current on-sight grade and UB VO2peak (r = .85, P = .001).

Conclusion:

UBT aerobic- and work-capacity results were strongly correlated to climbing-performance variables and reflected sport-specific fatigue, and TMT results were not. UBT is preferred to TMT to test and monitor dedicated and elite rock climbers’ training status.