Changes in strength and power performance and serum hormone concentrations during 12 weeks of task-specific or strength training in conscripts

The purpose of this study was to investigate the effects of two different training programs on strength and power performance and serum hormone concentrations. A total of 104 male soldiers volunteered and took part in the 12-week training period with baseline, mid-, and post-measurements of body composition, muscle strength, lower and upper body power, and blood samples to determine serum hormone concentrations. The mean (+/- SD) age of subjects was 20 +/- 1 years, height 180 +/- 6 cm and body mass 72.4 +/- 8.8 kg. The subjects were divided into three different training groups: soldier task-specific training (TS), strength training (ST), and control (CON). Each group had a total of 18 training sessions during the 12-week study. In the muscle strength tests, most improvements could be observed in the TS and ST groups, especially, during the first weeks of the training period. Maximal isometric leg extension force increased significantly by 7.9 +/- 12.2% (p < .05) in the TS and 7.1 +/- 12.6% (p < .05) in the ST groups between the PRE and MID, as well as between the PRE and POST measurements by 8.1 +/- 12.4% (p < .05) in TS and 12.3 +/- 15.3% (p < .01) in ST. Serum TES concentration increased significantly in TS between the PRE and MID (16.8 +/- 33.9%) and PRE and POST (11.2 +/- 16.7%) measurements. Serum COR concentrations decreased in TS between the MID and POST (-7.8 +/- 10.9%) and PRE and POST (-11.0 +/- 14.3%) measurements. Although the differences observed were rather minor in magnitude, training in the TS and ST groups led to greater improvements in muscle strength and power performance compared to the training in the CON group. The development of strength and/or power of the lower and upper body was greater in the TS and ST groups, which is crucial for warfighter's performance. Therefore, it is important to have a structured resistance-training program during military training to optimize the strength, power, and military-specific performance.