This study examined whether ground reaction force (GRF) asymmetry of 2-legged countermovement jumps (CMJ) is related to 1-legged CMJ asymmetry. The GRF asymmetry of a 2-legged CMJ has been suggested as a preferred test to the 1-legged CMJ for functional strength and power deficit assessment. Twenty-eight men and 30 women performed 5 trials each of a 1-legged CMJ with the right limband the left limb, and a 2-legged CMJ. Vertical GRFs were collected from each lower limb using 2 force platforms. Although several GRF variables were calculated, vertical impulse correlated most strongly with jump height in all conditions (p < 0.05), and they were used in subsequent analyses. A moderate correlation was found for impulse asymmetry between the 1- and 2-legged CMJs for women (r = 0.45, p < 0.05), but not for men (r = 0.06, p = 0.76). In contrast, cross-tabulation analyses of subjects presented with the same dominant characteristics in the 1- and 2-legged CMJs revealed poor associations for both men (Freeman-Halton exact p = 0.61) and women (Freeman-Halton exact p = 0.19). Only 11 women recorded the same dominant limb for both 1- and 2-legged CMJs. This suggests that impulse asymmetries found in the 1- and 2-legged CMJ were unrelated. As the 1-legged CMJ relies on the extension forces generated entirely from 1 limb, variations in jump heights and GRF impulses by left and right limbs separately were more indicative of functional strength differences between sides. Hence, it is recommended that the 1-legged CMJ is used when examining functional strength asymmetry in the lower limbs. In contrast, factors causing asymmetry in GRF impulses during 2-legged CMJs are more complicated and require further investigation.

This study examined the relationships between the performances of a swimming grab start and each of countermovement jump for distance, countermovement jump for height, squat jump for distance, and squat jump for height. Nine elite and 7 recreational female swimmers performed 6 trials in each of the 4 jumping techniques and six 25-m freestyle sprints after a grab start. Elite participants performed significantly better in the start performances, and this was attributed to the greater horizontal impulse. Correlations in the elite group revealed that grab-start performance was not related to performance of any jumps. This suggests that the grab start is independent of the jumping techniques for this group, and performance of one skill might not translate to performance in the other. Significant correlations were found between performance of the grab start and the 4 jumps in the recreational group, possibly because of adoption of an "incorrect" motor pattern that might be similar to those of the jumps. This study highlighted the importance of practicing the start as a whole skill during training.

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Six 9-, 11-, and 13-year-old, anthropometrically matched males and females were towed on the water surface via a mechanical winch at 1.3 to 2.5 ms−1 in increments of 0.3 ms−1 during a prone streamlined glide. Passive drag force of the 13-year age group was significantly larger than that of the 9-year age group at 1.9, 2.2, and 2.5 ms−1, but not at 1.3-1.6 ms−1. While anthropometry did not feature in any regression equation at any age for passive drag at velocities of 1.3 and 1.6 ms−1, body mass was the best predictor of drag at 1.9 and 2.5 ms−1.

Purpose: To investigate the effects of 8 weeks of upright water-based exercise training in people with type 2 diabetes.Methods: Thirteen participants with type 2 diabetes (54% male; 60.9 ± 9.6 years, mean ± standard deviation) completed eight weeks of upright water-based exercise training at a moderate intensity (60-80% of exercise test-derived maximum heart rate), for one hour, three times a week (TG). Fourteen participants (64% male; 63.9 ± 9.8 years) acted as a control group (CG) who maintained their usual activities. Pre-and post-intervention, participants performed cardiopulmonary exercise testing to determine VO2peak and one-repetition maximum testing to assess muscular strength. Blood profiles were assessed with standard assays. Body mass index and waist:hip ratio were employed as measures of anthropometry.Endothelium dependent (brachial artery flow mediated dilation (FMD)) and independent (GTN mediated) function were assessed using vascular ultrasound. Results:Water-based training increased VO2peak (18.5 ± 4.3 to 21.5 ± 5.4 ml.kg-1.min-1) (p=0.002), overall muscle strength (123 ± 44 to 139 ± 43kg) and leg strength (92 ± 28 to 104 ± 29kg), compared with the CG (p=0.001). The effect on pectoral strength (31 ± 17 to 35 ± 16kg) was not significantly different to the CG (24 ± 12 to 26 ± 14kg) (p=0.08). No change was observed in anthropometry, blood profiles, or GTN mediated vascular function. FMD was increased following training (6.1 ± 2.4 to 6.5 ± 3.0%), compared with controls who demonstrated a slight decrease (6.2 ± 1.6 to 5.4 ± 1.6%) (p=0.002). Conclusion:Water-based circuit training was well tolerated and appears to be an effective exercise modality for improving aerobic fitness, strength and vascular function in people with type 2 diabetes.