Browsing Sport and Exercise Sciences by Publisher "National Strength and Conditioning Association"
Now showing items 1-3 of 3
The effects of a cycling warm-up including high-intensity heavy-resistance conditioning contractions on subsequent 4 km time trial performancePrior exercise has been shown to improve subsequent performance via different mechanisms. Sport-specific conditioning contractions can be used to exploit the 'post-activation potentiation' (PAP) phenomenon to enhance performance although this has rarely been investigated in short endurance events. The aim of this study was to compare a cycling warm-up with PAP-inducing conditioning contractions (CW) with a moderate intensity warm-up (MW) on performance and physiological outcomes of 4 km time trial. Ten well-trained male endurance cyclists (V[Combining Dot Above]O2max 65.3 +/- 5.6 ml[middle dot]kg-1[middle dot]min-1) performed two 4 km cycling time trials following a 5-minute recovery after a warm-up at 60% of V[Combining Dot Above]O2max for 6.5-minutes (MW), and a warm-up with conditioning contractions (CW) consisting of 5 minutes at 60% of V[Combining Dot Above]O2max then 3 x 10-seconds at 70% of peak power interspersed with 30-seconds recovery. Blood lactate concentrations were measured before and after time trial. Expired gases were analysed along with time, power output (PO), and peak forces over each 500 m split. Following CW, mean completion time was reduced (1.7 +/- 3.5 s p > 0.05), PO increased (5.1 +/- 10.5 W p > 0.05) as did peak force per pedal stroke (5.7 +/- 11 N p > 0.05) when compared to MW. V[Combining Dot Above]O2 increased (1.4 +/- 1.6 ml[middle dot]kg-1[middle dot]min-1 p < 0.05) following CW, whilst RER decreased (0.05 +/- 0.02 p < 0.05). Physiological and performance differences following CW were greatest over the first 1500 m of the trials. The results suggest a PAP-inducing warm-up alters V[Combining Dot Above]O2 kinetics and can lead to performance improvements in short endurance cycling but work and recovery durations should be optimised for each athlete.
The effects of Bodymax high-repetition resistance training on measures of body composition and muscular strength in active adult womenThe purpose of this study was to investigate the effects of a light, high-repetition resistance-training program on skinfold thicknesses and muscular strength in women. Thirty-nine active women (mean age 38.64 +/- 4.97 years) were randomly placed into a resistance-training group (RT; n = 20) or a control group (CG; n = 19). The RT group performed a resistance-training program called Bodymax for 1 hour, 3 d.wk(-1), which incorporated the use of variable free weights and high repetitions in a group setting. The CG group continued its customary aerobic training for 1 hour 3 d.wk(-1). Five skinfold and 7 muscular strength measures were determined pretraining and after 12 weeks of training. Sum of skinfolds decreased (-17 mm; p < 0.004) and muscular strength increased (+57.4 kg; p < 0.004) in the RT group. Effect sizes for individual skinfold sites and strength measures were "medium" and "high," respectively. Bodymax is an effective resistance-training program for reducing skinfold thickness and increasing muscular strength in active women. Therefore, women with a similar or lower-activity status should consider incorporating such training into their regular fitness programs.
The reliability and validity of short-distance sprint performance assessed on a nonmotorized treadmillThis study examined the interday and intraday reliabilities and validities of various sprint performance variables on a nonmotorized treadmill (NMT) over distances of 10, 20, and 30 metres.