No abstract

The objectives of this study were to examine the effects of a moderate intensity strength training on changes in critical velocity (CV), anaerobic running distance (D'), sprint performance and Yo-Yo intermittent running test (Yo-Yo IR1) performances. Methods: two recreational soccer teams were divided in a soccer training only group (SO; n = 13) and a strength and soccer training group (ST; n = 13). Both groups were tested for values of CV, D', Yo-Yo IR1 distance and 30-m sprint time on two separate occasions (pre and post intervention). The ST group performed a concurrent 6-week upper and lower body strength and soccer training, whilst the SO group performed a soccer only training. Results: after the re-test of all variables, the ST demonstrated significant improvements for both, YoYo IR1 distance (p = 0.002) and CV values (p<0.001) with no significant changes in the SO group. 30-m sprint performance were slightly improved in the ST group with significantly decreased performance times identified in the SO group (p<0.001). Values for D' were slightly reduced in both groups (ST -44.5 m, 95% CI = -90.6 to 1.6; SO -42.6 m, 95% CI = -88.7 to 3.5). Conclusions: combining a 6-week moderate strength training with soccer training significantly improves CV, Yo-Yo IR1 whilst moderately improving 30-m sprint performances in non-previously resistance trained male soccer players. Critical Velocity can be recommended to coaches as an additional valid testing tool in soccer.

Background: High-intensity interval training (HIIT) is a well-established training modality to improve aerobic and anaerobic capacity. However, sex-specific aspects of different HIIT protocols are incompletely understood. This study aimed to compare two HIIT protocols with different recovery periods in moderately trained females and males and to investigate whether sex affects high-intensity running speed and speed decrement. Methods: Fifty moderately trained participants (30 females and 20 males) performed an exercise field test and were randomized by lactate threshold (LT) to one of two time-and workload-matched training groups. Participants performed a 4-week HIIT intervention with two exercise sessions/week: Group 1 (4 × 30,180 HIIT), 30-s all-out runs, 180-s active recovery and Group 2 (4 × 30,30 HIIT), 30-s all-out runs, 30-s active recovery. High-intensity runs were recorded, and speed per running bout, average speed per session, and speed decrement were determined. Blood lactate measurements were performed at baseline and follow-up at rest and immediately post-exercise. Results: Females and males differed in running speed at LT and maximal running speed determined during exercise field test (speed at LT, females: 10.65 ± 0.84 km h −1 , males: 12.41 ± 0.98 km h −1 , p < 0.0001; maximal speed, females: 14.55 ± 1.05 km h −1 , males: 17.41 ± 0.68 km h −1 , p < 0.0001). Estimated maximal oxygen uptake was ~52.5 ml kg −1 min −1 for females and 62.6 ml kg −1 min −1 for males (p < 0.0001). Analysis of HIIT protocols revealed an effect of sex on change in speed decrement (baseline vs. follow-up) in that females showed significant improvements only in the 4 × 30:30 HIIT group (p = 0.0038). Moreover, females performing the 4 × 30:30 protocol presented increased speed per bout and average speed per session at follow-up (all p ≤ 0.0204), while no effect was detected for females performing the 4 × 30:180 protocol. Peak blood lactate levels increased in all HIIT groups (all p < 0.05, baseline vs. follow-up), but males performing the 4 × 30:180 protocol showed no difference in lactate levels. Conclusions: If not matched for physical performance, females, but not males, performing a 4 × 30 HIIT protocol with shorter recovery periods (30 s) present increased average Schmitz et al.

by three TTE and three TT efforts interspersed by a 60-min recovery between efforts. 29Oxygen uptake was measured during all trials. The mean response time (MRT) was 30 calculated as a description of the overall ܸ ሶ O 2 kinetic response from the onset to 2 min of 31 exercise. Results: TTE determined CP was 279 ± 52W and TT determined CP was 276 32 ± 50W (P = 0.237). Values of W′ were 14.3 ± 3.4 kJ (TTE W′) and 16.5± 4.2 kJ (TT W′) 33 (P = 0.028). Whilst a high level of agreement (-12 to 17 W) and a low prediction error of 34 2.7% was established for CP, for W′ limits of agreements were markedly lower (-8 to 3.7 35 kJ) with a prediction error of 18.8%. The mean standard error for TTE CP values was 36 significantly higher than that for TT CP values (2.4 ± 1.9% vs. 1.2 ± 0.7% W). The 37 standard error for TTE W′ and TT W′ were 11.2 ± 8.1% and 5.6 ± 3.6%, respectively. 38The ܸ ሶ O 2 response was significantly faster during TT (~22 s) than TTE (~28 s).

No abstract