Regular moderate-intensity exercise (e.g. brisk walking) provides health benefits. In the present study, we compared the physiological and metabolic responses of playing the Nintendo Wii Sports tennis, baseball and boxing with self-paced brisk treadmill walking. Ten young-adults (21±1 years; 73.9±12.0 kg; 1.76±0.06 m) played each sport for 10 min with a 5 min rest interval or, in a separate session, walked briskly (6.1±0.6 km·h-1) with an equivalent time order wearing the Cosmed K4b2 metabolic system. In a bout of 10 min, the average values during Nintendo Wii boxing for physiological (i.e. minute ventilation, oxygen uptake and heart rate) and metabolic (i.e. energy expenditure, fat oxidation, carbohydrate oxidation and respiratory exchange ratio) responses were equal to brisk treadmill walking but lower for Nintendo Wii tennis and baseball (P<0.05). It was concluded that the physiological and metabolic responses of Nintendo Wii boxing would allow this game activity to be a viable part of a programme of structured exercise in young-adults to gain health benefits.
Muscle strength and fatigue resistance increases with resistance training. Resistance training adaptations can be enhanced with single-ingredient or dual-ingredient supplementation but less is known about resistance training adaptations by multi-ingredient supplementation. We examined the effects of a commercial multi-ingredient supplement on resistance training adaptations for training-specific and non-training-specific tasks in young males. Male participants (n = 16, age 21±2 years, body mass 74.5±5.9 kg, body height 177±5 cm) had at least 1 year experience with resistance training exercises. Training (7 muscle groups, 4 sessions/week, weekly adjustments) consisted of two 6 weeks blocks with 4 weeks between blocks. During training, participants consumed placebo (i.e. maltodextrin, n = 7) or the sports nutritional supplement Cyclone (Maximuscle Ltd, UK, n = 9) (main ingredients creatine monohydrate, whey protein, glutamine and HMB) twice daily with one intake <15 min following a training session. Unpaired Student's ttest was used for placebo and Cyclone group comparison of percentage changes with p < 0.05. Effect sizes (Cohen's d) were calculated for the Cyclone group. Cyclone did not enhance maximal voluntary isometric force (MVIF) (p = 0.56), time to fatigue at 70% MVIF (p = 0.41) and peak concentric strength (60°·s-1) (p = 0.66) of m.quadriceps femoris (i.e. the non-specific training tasks). For the specific-training tasks, Cyclone did not enhance one-repetition maximum (1-RM) of lateral pull (p = 0.48) but there was a trend and large effect size for 1-RM of bench press (p = 0.07, d = 0.98) and 45° leg press (p = 0.07, d = 1.41). Cyclone resulted in an increase in number of repetitions for 80% pre-training 1-RM for lateral pull (p = 0.02, d = 1.30), bench press (p = 0.03, d = 1.20) with a trend for 45° leg press (p = 0.08, d = 0.96). Cyclone during resistance training enhanced the performance of 1-RM and number of repetitions at 80% of pretraining 1RM of some training-specific tasks, all with large effect sizes. Our observations suggest that Cyclone during resistance training substantially improves the ability to perform training-related tasks.
The aim of the study was to examine whether self-selected walking speed during downhill treadmill walking by older adults would result in muscle injury and changes in physiological responses during level walking. Twenty-six participants (age: 67 ± 4 yrs; height: 1.69 ± 0.09 m; body mass: 74.9 ± 13.1kg) were assigned to level (n = 11, 30 min, 0%) or downhill walking (n=15, 30 min, -10%) at a self-selected walking speed. Self-selected walking speed and exercise intensity were similar for both groups (level: 4.2±0.4 km·hr-1, 42±6% VO2max; downhill: 4.6±0.6 km·hr-1, 44±15% VO2max). After 48-hours, downhill walking had reduced maximal voluntary isometric force of the m. quadriceps femoris (-15%, P<0.001), indicative of muscle injury, but no changes were observed for walking economy, minute ventilation, heart rate and respiratory exchange ratio during level walking. For older adults, downhill walking at a selfselected walking speed causes muscle injury without any detrimental effect on walking economy. Regular downhill walking at a self-selected walking speed by older adults is an eccentric endurance activity that may have the potential to improve cardiovascular fitness and muscle strength.
This study examined in older adults the effects of wearing the Cosmed K4b2 metabolic system with face mask during the 1-mile Rockport Fitness Walking Test (RFWT). A randomised cross-over design was used (13 males, 12 females, age: 67±4 (yrs). Walking time, walking speed and final heart rate were recorded and predicted VO2max calculated. Participants had a constant walking speed during the RFWT (P = 0.24) not influenced by wearing the Cosmed K4b2. Using Bland-Altman analysis, bias for walking time, heart rate and predicted VO2max was not significant. The predicted VO2max wearing the Cosmed K4b2 was within 0.05±0.36 L·min-1. Wearing the Cosmed K4b2 metabolic system with face mask did not influence 1-mile walking performance in older adults. This observation allows the Cosmed K4b2 metabolic system to be used during walking tests in older adults to examine metabolic and physiologic adaptations by controlled exercise interventions.
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