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Interleukin-15 (IL-15) is an anabolic cytokine that is produced in skeletal muscle and directly affects muscle anabolism in animal and in vitro models. The contribution of IL-15 variability in muscle responses to 10 wk of resistance exercise training in young men and women was examined by measuring acute and chronic changes in IL-15 protein in plasma and characterizing genetic variation in the IL-15 receptor-or gene (IL15RA). Participants trained 3 days a week at 75% of one repetition maximum, performing three sets (6–10 repetitions) of 13 resistance exercises. Plasma IL-15 protein was significantly increased (P < 0.05) immediately after acute resistance exercise but did not change with training and was not associated with variability in muscle responses with training. A single nucleotide polymorphism in exon 7 of ILISRA was strongly associated with muscle hypertrophy and accounted for 7.1% of the variation in regression modeling. A polymorphism in exon 4 was also independently associated with muscle hypertrophy and accounted for an additional 3.5% of the variation in hypertrophy. These results suggest that IL-15 is an important mediator of muscle mass response to resistance exercise training in humans and that genetic variation in IL15RA accounts for a significant proportion of the variability in this response. [ABSTRACT FROM AUTHOR]

The aim of this study was to predict indoor rowing performance in 12 competitive female rowers (age 21.3 +/- 3.6 years, height 1.68 +/- 0.54 m, body mass 67.1 +/- 11.7 kg; mean +/- s) using a 30 s rowing sprint, maximal oxygen uptake and the blood lactate response to submaximal rowing. Blood lactate and oxygen uptake (VO2) were measured during a discontinuous graded exercise test on a Concept II rowing ergometer incremented by 25 W for each 2 min stage; the highest VO2 measured during the test was recorded as VO2max (mean = 3.18 +/- 0.35 l.min-1). Peak power (380 +/- 63.2 W) and mean power (368 +/- 60.0 W) were determined using a modified Wingate test protocol on the Concept II rowing ergometer. Rowing performance was based on the results of the 2000 m indoor rowing championship in 1997 (466.8 +/- 12.3 s). Laboratory testing was performed within 3 weeks of the rowing championship. Submitting mean power (Power), the highest and lowest five consecutive sprint power outputs (Maximal and Minimal), percent fatigue in the sprint test (Fatigue), VO2max (l.min-1), VO2max (ml.kg-1.min-1), VO2 at the lactate threshold, power at the lactate threshold (W), maximal lactate concentration, lactate threshold (percent VO2max) and VEmax (l.min-1) to a stepwise multiple regression analysis produced the following model to predict 2000 m rowing performance: Time2000 = -0.163 (Power) -14.213.(VO2max l.min-1) +0.738.(Fatigue) 7.259 (R2 = 0.96, standard error = 2.89). These results indicate that, in the women studied, 75.7% of the variation in 2000 m indoor rowing performance time was predicted by peak power in a rowing Wingate test, while VO2max and fatigue during the Wingate test explained an additional 12.1% and 8.2% of the variance, respectively. [ABSTRACT FROM AUTHOR]

The aim of this study was to predict indoor rowing performance in 12 competitive female rowers (age 21.3 ± 3.6 years, height 1.68 ± 0.54 m, body mass 67.1 ± 11.7 kg; mean ±s) using a 30 s rowing sprint, maximal oxygen uptake and the blood lactate response to submaximal rowing. Blood lactate and oxygen uptake (VO[sub 2]) were measured during a discontinuous graded exercise test on a Concept II rowing ergometer incremented by 25 W for each 2 min stage; the highest VO[sub 2] measured during the test was recorded as VO[sub 2max] (mean = 3.18 ± 0.35 l· min[sup -1]). Peak power (380 ± 63.2 W) and mean power (368 ± 60.0 W) were determined using a modified Wingate test protocol on the Concept II rowing ergometer. Rowing performance was based on the results of the 2000 m indoor rowing championship in 1997 (466.8 ± 12.3 s). Laboratory testing was performed within 3 weeks of the rowing championship. Submitting mean power (Power), the highest and lowest five consecutive sprint power outputs (Maximal and Minimal), percent fatigue in the sprint test (Fatigue), VO[sub 2max] (l· min[sup -1]), VO[sub 2max] (ml·kg[sup -1] ·min[sup -1]), VO[sub 2] at the lactate threshold, power at the lactate threshold (W), maximal lactate concentration, lactate threshold (percent VO[sub 2max]) and VE[sub max] (l·min[sup -1]) to a stepwise multiple regression analysis produced the following model to predict 2000 m rowing performance: Time[sub 2000] =- 0.163 (Power)14.213 ·(VO[sub 2max] l· min[sup -1]) + 0.738· (Fatigue) + 567.259 (R[sup 2] = 0.96, standard error = 2.89). These results indicate that, in the women studied, 75.7% of the variation in 2000 m indoor rowing performance time was predicted by peak power in a rowing Wingate test, while VO[sub 2max] and fatigue during the Wingate test explained an additional 12.1% and 8.2% of the variance, respectively. [ABSTRACT FROM AUTHOR]

This study investigates the fluctuations of oxygen uptake in synchrony with repetitive climbing a circular boulder on an instrumented climbing wall. Oxygen consumption (VO, l/min) was measured with a portable battery-powered Cosmed K4b metabolic systems via open circuit indirect calorimetry and the movement sequence with time was identified from the force signals at different holds. The results show that the fluctuations of VO (l/min) are synchronised with climbing and depend on the route conditions, which, in turn, require different climbing techniques. The cyclic behaviour of respiration provoked by a circular boulder route suggests that the oxygen uptake is influenced by the climbing route even after the steady state is reached. [ABSTRACT FROM PUBLISHER]