The aim of this review was to highlight research that has focused on examining expressions of peak oxygen uptake (VO2peak) in children and youth, with special reference to allometric scaling. VO2peak is considered the highest VO2 during an increasing workload treadmill or bicycle ergometer test until volitional termination. We have reviewed scholarly works identified from PubMed, One Search, EBSCOhost and Google Scholar that examined VO2peak in absolute units (L·min(-1)), relative units [body mass, fat-free mass (FFM)], and allometric expressions [mass, height, lean body mass (LBM) or LBM of the legs raised to a power function] through July 2015. Often, the objective of measuring VO2peak is to evaluate cardiorespiratory function and fitness level. Since body size (body mass and height) frequently vary greatly in children and youth, expressing VO2peak in dimensionless units is often inappropriate for comparative or explanatory purposes. Consequently, expressing VO2peak in allometric units has gained increased research attention over the past 2 decades. In our review, scaling mass was the most frequent variable employed, with coefficients ranging from approximately 0.30 to over 1.0. The wide variance is probably due to several factors, including mass, height, LBM, sex, age, physical training, and small sample size. In summary, we recommend that since skeletal muscle is paramount for human locomotion, an allometric expression of VO2peak relative to LBM is the best expression of VO2peak in children and youth.

Implementation of the NAP SACC program in treatment daycare facilities resulted in significant increases in objectively measured physical activity levels, compared to the control group, demonstrating physical activity improvement in the treatment daycare centers.

This study examined energy expenditure and physiologic determinants for marathon performance in recreational runners. Twenty recreational marathon runners participated (10 males aged 41 +/- 11.3 years, 10 females aged 42.7 +/- 11.7 years). Each subject completed a V(.-)O2max and a 1-hour treadmill run at recent marathon pace, and body composition was indirectly determined via dual energy X-ray absorptiometry. The male runners exhibited higher V(.-)O2max (ml x kg(-1) x min(-1)) values (52.6 +/- 5.5) than their female counterparts (41.9 +/- 6.6), although ventilatory threshold (T-vent) values were similar between groups (males: 76.2 +/- 6.1 % of V(.-)O2max, females: 75.1 +/- 5.1%). The male runners expended more energy (2,792 +/- 235 kcal) for their most recent marathon as calculated from the 1-hour treadmill run at marathon pace than the female runners (2,436 +/- 297 kcal). Body composition parameters correlated moderately to highly (r ranging from 0.50 to 0.87) with marathon run time. Also, V(.-)O2max (r = -0.73) and ventilatory threshold (r = -0.73) moderately correlated with marathon run time. As a group, the participants ran near their ventilatory threshold for their most recent marathon (r = 0.74). These results indicate the influence of body size on marathon run performance. In general, the larger male and female runners ran slower and expended more kilocalories than smaller runners. Regardless of marathon finishing time, the runners maintained a pace near their T-vent, and as T-vent or V(.-)O2max increased, marathon performance time decreased.

Purpose:The aim of this investigation was to compare gender differences in physiologic and perceptual responses during a 1-h run at recent marathon pace and running economy at three speeds in recreational marathon runners.Methods:In a counterbalanced design, 10 men and 10 women completed a 1-h treadmill run and a running economy test. Treadmill speed for the 1-h run ranged from 141 to 241 m·min−1 and 134, 168, and 188 m·min−1 for running economy. Physiologic parameters (oxygen uptake, carbon dioxide production, pulmonary ventilation, and heart rate) and perceived exertion were measured. Repeated-measures ANOVA was used to compare any gender differences (P < .05) during the 1-h run and a two-way ANOVA was used to compare running economy. With this sample, estimated marathon energy expenditure, body composition, and maximal physiologic function was reported.1Results:With the exception of an allometric expression of VO2 (mL·min−1·kg BW−0.75), similar gender physiologic and perceptual responses were found during the 1-h run. Although not significant, the females exercised at a higher percent VO2max (8% to 9%) during the run. Similar gender differences were also noted during the running economy tests.Conclusions:Although the male runners completed a recent marathon significantly faster than the females, similar gender physiologic and perceptual responses were generally found during the 1-h treadmill run and the running economy tests.

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