A1 Journal article (refereed)
Effects of Combined Strength and Endurance Training on Body Composition, Physical Fitness, and Serum Hormones During a 6-Month Crisis Management Operation (2022)

Pihlainen, K., Kyröläinen, H., Santtila, M., Ojanen, T., Raitanen, J., & Häkkinen, K. (2022). Effects of Combined Strength and Endurance Training on Body Composition, Physical Fitness, and Serum Hormones During a 6-Month Crisis Management Operation. Journal of Strength and Conditioning Research, 36(9), 2361-2370. https://doi.org/10.1519/JSC.0000000000003902

JYU authors or editors

Publication details

All authors or editorsPihlainen, Kai; Kyröläinen, Heikki; Santtila, Matti; Ojanen, Tommi; Raitanen, Jani; Häkkinen, Keijo

Journal or seriesJournal of Strength and Conditioning Research



Publication year2022


Issue number9

Pages range2361-2370

PublisherLippincott Williams & Wilkins; National Strength and Conditioning Association

Publication countryUnited States

Publication languageEnglish


Publication open accessOpenly available

Publication channel open accessPartially open access channel

Publication is parallel published (JYX)https://jyx.jyu.fi/handle/123456789/73842


Very few studies have examined the impact of training interventions on soldier readiness during an international military operation. Therefore, the present study investigated the effects of combined strength and endurance training on body composition, physical performance, and hormonal status during a 6-month international military deployment consisting of typical peacekeeping tasks, e.g., patrolling, observation, and on-base duties. Soldiers (n = 78) were randomly allocated to a control group (C) or one of 3 combined whole-body strength and endurance training groups with varying strength-to-endurance training emphasis (Es = 25/75%, SE = 50/50% or Se = 75/25% of strength/endurance training). Body composition, physical performance (3000-m run, standing long jump [SLJ], isometric maximal voluntary contraction of the lower [MVC lower] and upper extremities [MVC upper ], muscle endurance tests), and selected serum hormone concentrations were determined prior to training (PRE), and after 9 (MID) and 19 (POST) weeks of training. Within- and between-group changes were analyzed using linear regression models. The average combined strength and endurance training frequency of the total subject group was 3 ± 2 training sessions per week. No changes were observed in physical performance variables in the intervention groups, whereas SLJ decreased by 1.9% in C (p < 0.05). Maximal voluntary contraction lower increased by 12.8% in the combined intervention group (p < 0.05), and this was significantly different to C (p < 0.05). Testosterone-to-cortisol ratio increased in SE and Se (p < 0.05), whereas no change was observed in C. The intervention groups maintained or improved their physical performance during deployment, which is beneficial for operational readiness. However, the high interindividual variation observed in training adaptations highlights the importance of training individualization during prolonged military operations.

Keywordsstrength trainingendurance trainingbody compositionphysical fitnesshormonal effectssoldierspeacekeeping operations

Free keywordsreadiness; performance; soldier; resistance and aerobic training; military

Contributing organizations

Ministry reportingYes

Reporting Year2022

Preliminary JUFO rating1

Last updated on 2024-03-04 at 20:35