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Abby R. Fleming, Nic Martinez, Larry H. Collins, Candi D. Ashley, Maureen Chiodini, Brian J. Waddell and Marcus W. Kilpatrick

of peak oxygen consumption (VO 2 peak). The fourth visit confirmed experimental workloads and familiarized participants to research procedures. The fifth and sixth visits included two experimental HIIT trials, both conducted at a workload confirmed to be 85% of VO 2 peak. All procedures were approved

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Amelia J. Carr, Philo U. Saunders, Laura A. Garvican-Lewis and Brent S. Vallance

training on elite athletes’ performance, particularly during major competitions, have not been conclusively determined, 4 , 5 but based on the existing literature, potential benefits include improved hemoglobin mass (Hb mass ), maximal oxygen uptake (VO 2 max), 6 submaximal exercise economy, 7 and

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Yongming Li, Margot Niessen, Xiaoping Chen and Ulrich Hartmann

extrapolation of the linear relationship between the intensity and oxygen uptake (VO 2 ) during submaximal (35–90% VO 2 max) exercise and calculates the energy into aerobic and anaerobic portions. The 3-component method subdivides the anaerobic portion into lactic and alactic shares. 14 , 15 The anaerobic

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Guro Strøm Solli, Pål Haugnes, Jan Kocbach, Roland van den Tillaar, Per Øyvind Torvik and Øyvind Sandbakk

increased blood flow to muscles and elevated baseline oxygen uptake (VO 2 ). 3 , 4 This alters the VO 2 kinetics and leads to a reduction of the initial oxygen deficit, postponing the anaerobic energy contribution to a later stage in the competition. 1 , 4 – 6 However, a too intense or long-lasting warm

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Andreas Schuchert and Thomas Meinertz

Context:

It is more feasible to assess functional capacity with an exercise test than to measure peak-exercise VO2.

Objective:

To assess whether maximal workload reliably predicts peak VO2.

Patients:

Thirty-six patients after aortic-valve replacement during routine follow-up.

Design:

Incremental symptom-limited cycle exercise test in the upright position with increments of 20 W/min.

Setting:

Out-clinic patients, university hospital.

Main Outcome Measures:

Maximal workload, ventilatory threshold, and peak VO2.

Results:

Maximal workload was 151 ± 39 W, and peak VO2, 1649 ± 486 ml/min. The correlation coefficient between maximal workload and peak VO2 was r = .92 (P < .0001). The regression equation for the estimation of peak VO2 was y = 11.7 (maximal workload in watts) – 110.7. Peak VO2 calculated with this equation was 1657 ± 451 ml/min.

Conclusions:

Maximal workload during ergometry in the upright position reliably predicted peak VO2.

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Fabiana A. Machado, >Luiz G. A. Guglielmo, Camila C. Greco and Benedito S. Denadai

The objective of this study was to verify the effect of the exercise mode on slow component of VO2 (VO2SC) in children aged 11–12 years during severe-intensity exercise. After determination of the lactate threshold (LT) and peak VO2 (VO2peak) in both cycling (CE) and running exercise (TR), fourteen active boys completed a series of “square-wave” transitions of 6-min duration at 75%∆ [75%∆ = LT + 0.75 × (VO2peak—LT)] to determine the VO2 kinetics. The VO2SC was significantly higher in CE (180.5 ± 155.8 ml • min−1) than in TR (113.0 ± 84.2 ml · min−1). We can conclude that, although a VO2SC does indeed develop during TR in children, its magnitude is considerably lower than in CE during severe-intensity exercise.

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Avish P. Sharma, David J. Bentley, Gaizka Mejuto and Naroa Etxebarria

VO 2 max, different submaximal thresholds, and exercise economy or mechanical efficiency. However, as endurance sporting events move closer to city centers aiming to gather crowds and improve spectator experience, an indirect phenomenon has emerged; altered race and consequently physiological demands

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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 (r 2 = .96, mean difference = 17 mL/min, SEE = 3.8%).

Conclusions:

The high correlation (r 2 = .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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Barbara E. Ainsworth, Robert G. McMurray and Susan K. Veazey

The purpose of this study was to determine the accuracy of two submaximal exercise tests, the Sitting-Chair Step Test (Smith & Gilligan. 1983) and the Modified Step Test (Amundsen, DeVahl, & Ellingham, 1989) to predict peak oxygen uptake (VO2 peak) in 28 adults ages 60 to 85 years. VO2 peak was measured by indirect calorimetry during a treadmill maximal graded exercise test (VO2 peak, range 11.6–31.1 ml · kg −l · min−1). In each of the submaximal tests, VO2 was predicted by plotting stage-by-stage submaximal heart rate (HR) and perceived exertion (RPE) data against VO2 for each stage and extrapolating the data to respective age-predicted maximal HR or RPE values. In the Sitting-Chair Step Test (n = 23), no significant differences were observed between measured and predicted VO2 peak values (p > .05). However, predicted VO2 peak values from the HR were 4.3 ml · kg−1 · min−1 higher than VO2 peak values predicted from the RPE data (p < .05). In the Modified Step Test (n = 22), no significant differences were observed between measured and predicted VO2 peak values (p > .05). Predictive accuracy was modest, explaining 49–78% of the variance in VO2 peak. These data suggest that the Sitting-Chair Step Test and the Modified Step Test have moderate validity in predicting VO2 peak in older men and women.

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Katherine E. Robben, David C. Poole and Craig A. Harms

A two-test protocol (incremental/ramp (IWT) + supramaximal constant-load (CWR)) to affirm max and obviate reliance on secondary criteria has only been validated in highly fit children. In girls (n = 15) and boys (n = 12) with a wide range of VO2max (17–47 ml/kg/min), we hypothesized that this procedure would evince a VO2-WR plateau and unambiguous VO2max even in the presence of expiratory flow limitation (EFL). A plateau in the VO2-work rate relationship occurred in 75% of subjects irrespective of EFL There was a range in RER at max exercise for girls (0.97–1.14; mean 1.06 ± 0.04) and boys (0.98−1.09; mean 1.03 ± 0.03) such that 3/15 girls and 2/12 boys did not achieve the criterion RER. Moreover, in girls with RER > 1.0 it would have been possible to achieve this criterion at 78% VO2max. Boys achieved 92% VO2max at RER = 1.0. This was true also for HRmax where 8/15 girls’ and 6/12 boys’ VO2max would have been rejected based on HRmax being < 90% of age-predicted HRmax. In those who achieved the HRmax criterion, it represented a VO2 of 86% (girls) and 87% (boys) VO2max. We conclude that this two-test protocol confirms VO2max in children across a threefold range of VO2max irrespective of EFL and circumvents reliance on secondary criteria.