The aim of this study was to investigate the effects of high-intensity interval running and small-sided game training programs on the physical capacity and the level of soccer-specific technical skills in young soccer players. Twenty male soccer players (U-16) were divided into two groups (running group – RG, small-sided game group – SSGG) and completed two different 8-week training programs. The intervention consisted of two training sessions a week (RG – 5×4 min running, with an active recovery period of 3 min; SSGG–3vs.3 games or 3vs.3 with a neutral player for 5×4 min, with an active recovery period of 3 min). A significant group × time interaction was found in the VO2max (p = 0.025). Moreover, the significant pre to post changes of VO2max were observed in the SSGG (p = 0.032). The differences between the results of shuttle runs and sprint tests were not significant with the exception of 5 m sprint in RG (p = 0.04). An improvement in the peak power and total work capacity was observed in the RG and SSGG. A significant improvement (p = 0.014) in soccer-specific technical skills level was noted only in the SSGG. The results of this study suggest that the small-sided games, compared with interval running, are more highly recommended training drills for the coincident development of physical capacity and technical skills in young soccer players.

The main purpose of this study was to determine the effect of different interval training regimes on the physical capacity and soccer-specific skills of young soccer players. Twenty-two subjects were divided into two groups: small-sided games group (SSGG; age: 15.8 ± 0.63 y, body mass: 61.6 ± 8.97 kg, height: 175.0 ± 6.23 cm) or interval-running group (IRG; age: 15.8 ± 0.55 y, body mass: 62.7 ± 8.69 kg, height: 177.6 ± 6.48 cm). The groups completed two different 8-week training programs. The intervention consisted of two training sessions per week (IRG – 7 × 3 min running where each bout consisted of 15 s of high-intensity running and 15 s of jogging with an active recovery period of 3 min; SSGG – 3 vs. 3 games for 7 × 3 min, with an active recovery period of 3 min). Significant changes over time were found in V̇O2max (p = 0.009, η2 = 0.29) and peak power (p = 0.014, η2 = 0.26). Post-hoc analysis revealed a significant increase in the maximal oxygen uptake only in the SSG group (p = 0.019). No significant improvement in running speed was found. The mean HR at AT increased significantly in both groups. A relevant correlation (group × time) was found for oxygen uptake at the AT intensity (p = 0.015, η2 = 0.26). A significant time effect was also present with respect to this variable (p = 0.000, η2 = 0.61). Post-hoc analysis of the V̇O2/AT index revealed no relevant (p = 0.19) improvements in the IRG (from 44.1 ± 5.72 to 46.0 ± 5.03 ml·kg−1·min−1), but there was a significant (p = 0.000) increase in the SSG (from 40.9 ± 3.51 to 46.0 ± 3.88 ml·kg−1·min−1). The improvement in soccer-specific skills was not significant (3.2 % in IRG and 5.3 % in SSGG). The results of this study show that small-sided games and running can both be efficient training strategies for developing aerobic capacity and soccer-specific skills.

Contact of humans with the earth, either directly (e.g., with bare feet) or using a metal conductor, changes their biochemical parameters. The effects of earthing during physical exercise are unknown. This study was carried out to evaluate selected biochemical parameters in subjects who were earthed during cycling. In a double-blind, crossover study, 42 participants were divided into two groups and earthed during exercise and recovery. One group was earthed in the first week during 30 minutes of cycling exercise and during recovery, and a second group was earthed in the second week. A double-blind technique was applied. Blood samples were obtained before each training session, after 15 and 30 minutes of exercise, and after 40 minutes of recovery. Significantly lower blood urea levels were observed in subjects earthed during exercise and relaxation. These significant differences were noted in both groups earthed at the beginning of exercise (P < 0.0001), after 15 (P < 0.0001) and 30 minutes (P < 0.0001) of exercise, and after 40 minutes of relaxation (P < 0.0001). Creatinine concentrations in earthed subjects during exercise were unchanged. Conclusions. Earthing during exercise lowers blood urea concentrations and may inhibit hepatic protein catabolism or increase renal urea excretion. Exertion under earthing may result in a positive protein balance.

The aim of the study was to assess the anaerobic threshold (lactate threshold LT) changes during winter and summer preparation period in soccer premier league and first division players. It was assumed that the index value varies depending on the stage of a one-year training cycle. Tests were conducted on the premier league and first division soccer players. Physical capacity tests were carried out at the beginning and at the end of the winter and summer preparation period. The tests covered 3 years: 2008-2010. Subjects performed an incremental running test according to Jastrzębski's method. The most important data obtain ed from this test are: running speed (V/LT) and heart rate (HR/LT) at LT.

No abstract