Physiological and perceptual responses at ventilatory threshold (VT) and V̇O2 peak were examined in 10 male children (10.2 ± 1.3 yrs) during graded treadmill and cycle exercise. Treadmill V̇O2peak (57.9 ± 6.7 ml · kg−1 · min−1) was higher (p < .05) than the cycle (51.7 ± 7.7 ml · kg−1 · min−1). Ventilation and heart rate (HR) were higher (p < .05) on the treadmill, while respiratory exchange ratio (RER), rating of perceived exertion (RPE), capillary blood lactate, and test duration were similar between tests. The V̇O2 at VT was higher (p < .05) on the treadmill (36.7 ± 4.6 ml · kg−1 · min−1) than the cycle (32.5 ± 4.4 ml · kg−1 · min−1). When VT was expressed as a percentage of V̇O2 peak, there was no difference (p > .05) between tests. The RPE at VT, HR at VT, and VT expressed as a percentage of HRpeak were also similar (p > .05) between tests. Similar to V̇O2 peak, the V̇O2 at VT is dependent on the mode of exercise. However, when VT is expressed as a percentage of V̇O2 peak, it is independent of testing modality. The RPE at VT appears to be linked to a percentage of V̇O2 peak rather than an absolute V̇O2.
Glen E. Duncan, Anthony D. Mahon, Julie A. Gay and Jennifer J. Sherwood
Emma L. J. Eyre, Jason Tallis, Susie Wilson, Lee Wilde, Liam Akhurst, Rildo Wanderleys and Michael J. Duncan
ActiGraph monitors, suggesting it provides a valid and accurate estimate of physical activity intensities ( John, Tylo & Basset, 2010 ; Plasqui & Westerterp, 2007 ). A newer tool, the GENEActiv, has demonstrated excellent reliability and validity against breath-by-breath VO 2 , derived from indirect
Livia Victorino Souza, Franciele De Meneck, Vanessa Oliveira, Elisa Mieko Higa, Eliana Hiromi Akamine and Maria do Carmo Franco
recorded and used to calculate the VO 2 max (mL/kg/min) according to the equation proposed by Leger and Lambert ( 23 ) and validated for children and adolescents ( 24 ). Blood Pressure Evaluation Blood pressure was evaluated according Fourth National Task Force on High Blood Pressure in Children and
Trent Stellingwerff, Ingvill Måkestad Bovim and Jamie Whitfield
= phosphocreatine; PRO = protein; RFD = rate of force development; suppl. = supplementation; SV = stroke volume; VO 2 max = maximal oxygen consumption. Middle-distance race intensity is extreme, with 800- to 5,000-m races being at ∼95% to 130% of VO 2 max ( Duffield et al., 2005 ), or 75–85% of maximum sprint speed
Twan ten Haaf, Selma van Staveren, Danilo Iannetta, Bart Roelands, Romain Meeusen, Maria F. Piacentini, Carl Foster, Leo Koenderman, Hein A.M. Daanen and Jos J. de Koning
index, 23.5 [2.1] kg/m 2 ; and VO 2max at baseline, 51.8 [6.3] mL/kg/min). Subjects were categorized in performance levels 1 (4%), 2 (57%), 3 (25%), and 4 (14%) according to VO 2max -based athlete classification norms. 10 , 11 Subjects gave written informed consent prior to the first measurements. The
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.
Timothy R. McConnell, Jean H. Haas and Nancy C. Conlin
Thirty-eight children (mean age 12.2 ±3.6 yrs) were tested to (a) compare the training heart rate (HR) and oxygen uptake (V̇O2) computed from commonly used exercise prescription methods to the heart rate (HRAT) and V̇O2 (ATge) at the gas exchange anaerobic threshold, (b) compute the range of relative HRs and V̇O2s (% HRmax and % V̇O2max, respectively) at which the ATge occurred, and (c) discuss the implications for prescribing exercise intensity. The ATge occurred at a V̇O2 of 20.9 ml · kg−1 · min−1 and an HR of 129 beats·min−1. The training HR and V̇O2 computed using 70 and 85% HRmax, 70% of the maximal heart rate reserve (HRR), and 57 and 78% V·O2max, were significantly different (p<.05) from their corresponding ATge values. To compute training % HRmax, % V̇O2max, and % HRR values that would not significantly differ from the ATge, then 68% HRmax, 48% V̇O2max, and 41% HRR would need to be used for the current population.
Han C.G. Kemper and Lando L.J. Koppes
The purpose of this study was to test the hypothesis that physical activity (PA), measured over a period of 23 years, is beneficial to aerobic fitness (VO2max) in boys and girls (13-36 years) who were enrolled in the Amsterdam Growth and Health Longitudinal Study (AGAHLS). PA was measured using a standardized activity interview. VO2max was assessed directly with a maximal running test on a treadmill. To assess the longitudinal relationship between PA and VO2max, different longitudinal analyses were carried out over different age periods, correcting for various confounders such as lifestyle parameters, biological parameters, and initial VO2max. Highly significant relationships (p < .05) were observed between PA and VO2max in four of the five analyses. However, in an autoregression analysis, when current PA has been related to the future change in VO2max, the results are not any more significant (p > .05). Analysis of the data of PA and VO2max from the AGAHLS population does not fully support the hypothesis that PA affects VO2max.
Stanley P. Brown, Joel C. Jordan, Linda F. Chitwood, Kim R. Beason, John G. Alvarez and Kendal P. Honea
This study was performed to investigate the relationship between heart rate (HR) as a percentage of peak HR and oxygen uptake (V̇O2) as a percentage of peak V̇O2 in older adults while performing deep water running (DWR). Twenty-three (14 male and 9 female) apparently healthy older adults, age 50 to 70 years, volunteered. Deep water running to V̇O2peak was performed in 3-min stages at leg speeds controlled by a metronome beginning at 60 strides per minute and increasing 12 strides per minute each additional stage. Oxygen uptake and HR were continuously monitored by open-circuit spirometry and radiotelemetry, respectively. Simple linear regression analysis was used to establish the relationship between the physiological variables. The relationship between %V̇O2peak and %HRpeak was statistically significant, with the male (%V̇O2peak = 1.5301 [%HRpeak] − 54.4932 [r = .96, SEE = 6.0%]) and female (%V̇O2peak = 1.5904 [%HRpeak] - 62.3935 [r = .91, SEE = 6.9%]) regression equations being significantly different (p < .05). The regression equations of older adults and those for college-aged males (%VO2peak = 1.4634 [%HRpeak] − 49.619) and females (%V̇O2peak = 1.6649 [%HRpeak] − 67.862) were not significantly different.
Thomas Rowland, Paul Vanderburgh and Lee Cunningham
Adjustment of VO2max for changes in body size is important in evaluating aerobic fitness in children. It is important, therefore, to understand the normal relationship between changes VO2max and body size during growth. Over the course of 5 years, 20 children (11 boys, 9 girls) underwent annual maximal treadmill testing to determine VO2max. The mean longitudinal allometric scaling exponent for VO2max relative to body mass (M) was 1.10 ± 0.30 in the boys and 0.78 ± 0.28 in the girls (p < .05). Respective cross-sectional values were 0.53 ± 0.08 and 0.65 ± 0.03. VO2max expressed relative to M1.0, M0.75, and M0.67 rose during the 5 years in the boys, but not the girls. Significant gender differences remained when VO2max was related to lean body mass. These findings suggest (a) factors other than body size affect the development of VO2max in children, and (b) gender differences exist in VO2max during childhood which are independent of body composition.