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Diego Chaverri, Thorsten Schuller, Xavier Iglesias, Uwe Hoffmann and Ferran A. Rodríguez

Purpose:

Assessing cardiopulmonary function during swimming is a complex and cumbersome procedure. Backward extrapolation is often used to predict peak oxygen uptake (V̇O2peak) during unimpeded swimming, but error can derive from a delay at the onset of V̇O2 recovery. The authors assessed the validity of a mathematical model based on heart rate (HR) and postexercise V̇O2 kinetics for the estimation of V̇O2peak during exercise.

Methods:

34 elite swimmers performed a maximal front-crawl 200-m swim. V̇O2 was measured breath by breath and HR from beat-to-beat intervals. Data were time-aligned and 1-s-interpolated. Exercise V̇O2peak was the average of the last 20 s of exercise. Postexercise V̇O2 was the first 20-s average during the immediate recovery. Predicted V̇O2 values (pV̇O2) were computed using the equation: pV̇O2(t) = V̇O2(t) HRend-exercise/HR(t). Average values were calculated for different time intervals and compared with measured exercise V̇O2peak.

Results:

Postexercise V̇O2 (0–20 s) underestimated V̇O2peak by 3.3% (95% CI = 9.8% underestimation to 3.2% overestimation, mean difference = –116 mL/min, SEE = 4.2%, P = .001). The best V̇O2peak estimates were offered by pV̇O2peak from 0 to 20 s (r2 = .96, mean difference = 17 mL/min, SEE = 3.8%).

Conclusions:

The high correlation (r2 = .86–.96) and agreement between exercise and predicted V̇O2 support the validity of the model, which provides accurate V̇O2peak estimations after a single maximal swim while avoiding the error of backward extrapolation and allowing the subject to swim completely unimpeded.

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Joaquin U. Gonzales, Jordan Shephard and Neha Dubey

We tested the hypothesis that the intensity of daily ambulation would relate with functional walking capacity in older adults. Forty-three women (n = 25) and men (n = 18) between the ages of 60-78 years wore an accelerometer for measurement of average daily steps and 30-min peak stepping cadence. A 400-m walk test was used to measure walking speed. No sex difference was found for average daily steps (p = .76), average peak cadence (p = .96), or walking speed (p = .89). Daily steps (women: r = .68, p < .01; men: r = .04) and peak cadence (women: r = .81, p < .01; men: r = −.16) were positively correlated with walking speed in women but not in men. After controlling for daily steps, peak cadence remained significantly associated with walking speed in women (partial r = .61, p < .01). Walking intensity during daily ambulation is independently related to functional walking capacity in older adults, albeit this relation may be more significant for women than men.

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Susan A. Jackson and Glyn C. Roberts

This study investigated relationships among peak performance, flow, goal orientation, and perceived ability in an attempt to ascertain possible conceptual bases to peak performance. Collegiate athletes (N=200) answered a questionnaire that assessed mastery and competitive goal orientations, perceived ability, flow, and experience in best and worst competitive performances. It was hypothesized that the psychological process of flow underlies peak performance and is associated with a mastery oriented focus and high perceived ability. These predicted relationships were supported by both quantitative and qualitative analyses. Analysis of athletes’ best performances indicated a total focus on performance, and other characteristics of flow were key to the perception of a superior state of functioning. In contrast, overconcern with the outcome, reflecting a competitive orientation, was often associated with athletes’ worst performances. These associations suggest that investigating positive performance states from a motivational standpoint may lead to greater understanding of the underlying conceptual bases of peak athletic performance.

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Magnus Dencker, Bianca Hermansen, Anna Bugge, Karsten Froberg and Lars B. Andersen

This study investigated the predictors of aerobic fitness (VO2PEAK) in young children on a population-base. Participants were 436 children (229 boys and 207 girls) aged 6.7 ± 0.4 yrs. VO2PEAK was measured during a maximal treadmill exercise test. Physical activity was assessed by accelerometers. Total body fat and total fat free mass were estimated from skinfold measurements. Regression analyses indicated that significant predictors for VO2PEAK per kilogram body mass were total body fat, maximal heart rate, sex, and age. Physical activity explained an additional 4–7%. Further analyses showed the main contributing factors for absolute values of VO2PEAK were fat free mass, maximal heart rate, sex, and age. Physical activity explained an additional 3–6%.

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Gregory B. Dwyer and Anthony D. Mahon

Little is known about the responses to graded exercise in athletes with cerebral palsy (CP). This study compared the ventilatory threshold (VT) and peak VO2 among athletes with CP during treadmill and cycle ergometry exercise. Six (4 men, 2 women) track athletes with CP volunteered to participate in the study. Graded exercise tests on a treadmill and cycle ergometer were performed on separate days to assess VT and peak VO2. Paired t tests were used to compare the two exercise modes. The VT, expressed as a percentage of peak VO2, was significantly higher on the cycle ergometer than on the treadmill. The absolute VO2 at the VT was similar during both testing modes, and peak VO2 was significantly higher on the treadmill than on the cycle ergometer. Similar to responses seen in able-bodied individuals, the VO2 at VT was similar during both modes of exercise, while the peak VO2 was 10% lower on the cycle than on the treadmill. Cycle ergometer peak VO2 in these athletes was higher than previous reports of individuals with CP for the cycle ergometer.

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Michael J. Duncan, Joanne Hankey and Alan M. Nevill

This study examined the efficacy of peak-power estimation equations in children using force platform data and determined whether allometric modeling offers a sounder alternative to estimating peak power in pediatric samples. Ninety one boys and girls aged 12–16 years performed 3 countermovement jumps (CMJ) on a force platform. Estimated peak power (PPest) was determined using the Harman et al., Sayers SJ, Sayers CMJ, and Canavan and Vescovi equations. All 4 equations were associated with actual peak power (r = 0.893−0.909, all p < .01). There were significant differences between PPest using the Harman et al., Sayers SJ, and Sayers CMJ equations (p < .05) and actual peak power (PPactual). ANCOVA also indicated sex and age effect for PPactual (p < .01). Following a random two-thirds to one-third split of participants, an additive linear model (p = .0001) predicted PPactual (adjusted R 2 = .866) from body mass and CMJ height in the two-thirds split (n = 60). An allometric model using CMJ height, body mass, and age was then developed with this sample, which predicted 88.8% of the variance in PPactual (p < .0001, adjusted R 2 = .888). The regression equations were cross-validated using the one-third split sample (n = 31), evidencing a significant positive relationship (r = .910, p = .001) and no significant difference (p = .151) between PPactual and PPest using this equation. The allometric and linear models determined from this study provide accurate models to estimate peak power in children.

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Liam P. Kilduff, Huw Bevan, Nick Owen, Mike I.C. Kingsley, Paul Bunce, Mark Bennett and Dan Cunningham

Purpose:

The ability to develop high levels of muscle power is considered an essential component of success in many sporting activities; however, the optimal load for the development of peak power during training remains controversial. The aim of the present study was to determine the optimal load required to observe peak power output (PPO) during the hang power clean in professional rugby players.

Methods:

Twelve professional rugby players performed hang power cleans on a portable force platform at loads of 30%, 40%, 50%, 60%, 70%, 80%, and 90% of their predetermined 1-repetition maximum (1-RM) in a randomized and balanced order.

Results:

Relative load had a significant effect on power output, with peak values being obtained at 80% of the subjects’ 1-RM (4466 ± 477 W; P < .001). There was no significant difference, however, between the power outputs at 50%, 60%, 70%, or 90% 1-RM compared with 80% 1-RM. Peak force was produced at 90% 1-RM with relative load having a significant effect on this variable; however, relative load had no effect on peak rate of force development or velocity during the hang power clean.

Conclusions:

The authors conclude that relative load has a significant effect on PPO during the hang power clean: Although PPO was obtained at 80% 1-RM, there was no significant difference between the loads ranging from 40% to 90% 1-RM. Individual determination of the optimal load for PPO is necessary in order to enhance individual training effects.

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Bareket Falk and Oded Bar-Or

A mixed cross-sectional longitudinal design was used to study the effect of growth and physical maturation on peak aerobic and anaerobic mechanical power. Subjects were divided into three groups based on Tanner staging: 16 prepubertal (PP, Stage 1), 15 midpubertal (MP, Stages 2, 3, 4), and 5 late pubertal (LP, Stage 5). Aerobic and anaerobic power were observed every 6 months for IS months. Peak mechanical aerobic power and peak oxygen consumption were determined using a progressive cycle ergometer test. Anaerobic power indices were derived from the Wingate Anaerobic Test. There was no difference in peak mechanical aerobic power (in W · kg−1) among the maturation groups, nor with chronological age. There was a significant difference in peak and mean anaerobic power (in W · kg−1) among maturation groups, but the increase with chronological age was not statistically significant. There was a significant correlation between aerobic and anaerobic power (in Watt) during each session among the PP and MP boys but not among the LP boys. This may suggest that the child’s metabolic specialization into either an aerobic or anaerobic performer begins in late puberty.

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Kenneth H. Pitetti, A. Lynn Millar and Bo Fernhall

The purpose of this study was to compare test-retest reliability when measuring peak physiological capacities of children and adolescents (age = 13.6 ± 2.9 yr) with mental retardation (MR) and their peers (12.0 ± 2.9 yr) without mental retardation (NMR) using a discontinuous treadmill (TM) protocol. Forty-six participants (23 MR = 12 male and 11 female; 23 NMR = 12 male and 11 female) completed two peak performance treadmill tests with 3 to 7 days of rest between tests. Physiological values measured included V̇O2peak (1 $$ min-1 and ml $$ kg-1 $$ min-1), V̇Epeak (1 $$ mhr-1), HRpeak (bpm), and RER (V̇O2 $$ V̇O2 -1). Test-retest reliability coefficients ranged from .85 to .99 for participants with MR and from .55 to .99 for participants without MR. Test reliability and accuracy in the present study does not appear to differ between the NMR and MR participants.

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John A. Mercer, Janet S. Dufek and Barry T. Bates

Objective:

To compare peak oxygen consumption (VO2) and heart rate (HR) during treadmill (TM) running and exercise on an elliptical trainer (ET).

Design:

A graded exercise test (GXT) during TM running and ET exercise.

Participants:

Physically active college students (N = 14; 25 ± 4.6 years). Each completed a TM GXT and ET GXT on separate days.

Results:

There were no differences in either VO2peak or peak HR between TM (53.0 ± 7.7 ml · kg–1 · min–1, 193.4 ± 9.4 bpm) and ET (51.6 ± 10.7 ml · kg–1 · min–1, 191.2 ± 11.5 bpm; P > .05). Correlations between HR and VO2 data for all stages of exercise for all subjects were similar between machines (ET: r = .88; TM: r = .95; P > .05).

Conclusion:

No adjustments to the target HR used during TM running are necessary when using the ET.