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

Abstract

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. K E Y W O R D S hormonal, Physical training, power, soldiers, strength Correction Statement: Correction added on 12 May 2020 after first online publication: Figure 1 has been amended in this version.

High precision but systematic offset in a standing bioelectrical impedance analysis (BIA) compared with dual-energy X-ray absorptiometry (DXA)

“…The InBody system has already been used extensively in male military conscript training studies in Finland. [45][46][47] CONCLUSIONS More than 25 years after the 1994 NIH Consensus Committee recommendations on research gaps in BIA technology for body composition applications, the technology is proving to be more reliable and useful for field research and in weight management programmes. At least one commercial system (InBody 770) provides body composition predictions that are comparable with a longstanding laboratory BIA device (RJL System), with devices and algorithms that both predict criterion measures based on the DXA system.…”

“…This is important in physical training programmes and perhaps even for physical employment standards for jobs requiring at least a minimum threshold of lean mass for safe and effective task performance. The InBody system has already been used extensively in male military conscript training studies in Finland 45–47…”

Combat tasks and physical readiness of military personnel: a systematic review

“…Traditional military physical training sessions last around an hour and the weekly frequency varies between three and five times a week. Their methodological approach ignores the planning, organization, and structuring of training loads, known as periodization, and the physical training sessions are composed of calisthenic exercises, long-distance and low-intensity running, and sporting activities (collective games and ball sports) [4][5][6] . Although they are related with maintaining health and individual well-being, these activities contribute little to increasing or maintaining the troop's readiness levels 6 .…”

“…Countries such as the United States, Finland, and Australia have discussed the implementation of training programs guided according to the actions that will be used in the battlefield [7][8][9] . These actions -known as combat tasks -can be defined as a set of critical physical techniques, skills, and performance for the employment of an operational function and measurement of a troop's readiness states 10 .…”

Impact of 12 weeks of basic military training on testosterone and cortisol responses

“…Circulating levels of cortisol and testosterone, and the testosterone:cortisol (T:C) ratio, which represents the balance between anabolic and catabolic activity, have been touted as markers of excessive training stress and inadequate recovery in non-military populations 2 3. Basal cortisol and testosterone concentrations are also sensitive to various forms of military training including BMT, trade-specific training and field training 1 4 7–15. However, these military training activities differed in length (1–44 weeks), type of training (eg, BMT, trade-specific training, field training, special forces selection course) and the military population (recruits, qualified soldiers, special forces candidates) making comparison difficult.…”