Doctors, trainers, and coaches prescribe exercise protocols to increase performance within many disciplines (i.e. diabetes control, post-operative exercise). Exercise protocols can be a litany of modalities stemming from endurance, strength, hypertrophy, or power. The outcome goal for individuals or team elucidates the specific programming of modality needed. Concurrent training is one such modality that incorporates endurance and strength training.
Concurrent training brings controversy as to whether both modalities can coexist and do not interfere with each training adaptation. Fyfe, Bishop, and Stepto (2014) reviewed the current literature which suggests that combining both training methods will attenuate gains in muscle mass, strength, and power compared to undertaking resistance training alone. In a meta-analysis by Wilson et al. (2012), effect sizes were compared for strength, hypertrophy, endurance, power, and concurrent training modalities. Interference effects of aerobic training are primarily body part specific because decrements were found in lower, but not upper body exercises (Wilson et al., 2012). There are a plethora of variables that should be considered if concurrent training prescription is to be utilized.
The participant’s training status is one variable that is considered when implementing concurrent training programming. An untrained or sedentary individual will presumably see larger benefits from concurrent training. As a trainer, two common goals that I deal with in this population is reduced body fat and increased strength. Running concurrent training exhibited larger effect sizes compared to cycling concurrent training and strength training alone (Wilson et al., 2012). Well-trained individuals can be affected by concurrent training prescription. Rhea et al. (2008) revealed that concurrent training effects power adaptations in NCAA Division 1 baseball players. Sixteen male Division 1 baseball players were randomly assigned to one of two in-season programs—SPT group or END group. Each group participated in 2-3 d·wk resistance training. Differences between groups were the metabolic training performed, SPT performed repeated maximal sprints ranging from 15-to 60 meters and the END group performed moderate- to high-intensity aerobic exercise (Rhea et al., 2008). Results showed that SPT group improved power (i.e. watts) compared to END group. It can be speculated that the further components are apart in the fitness continuum the less compatibility (Rhea et al., 2008).
Programming variables are additional considerations when implementing concurrent training. Duration, frequency and volume of endurance training could interfere with strength/hypertrophy adaptations (Jones, Howatson, Russell, & French, 2013). Jones et al. (2013) discovered that larger ratios of strength training combined with endurance training (i.e. 3:1 ratio) increased time to exhaustion and limb girth compared to control and comparable strength and endurance ratios (i.e. 1:1). However, if endurance ratios are greater than strength, hypertrophy, or power training reductions in these various performance adaptations are observed (de Souza et al., 2013).
De Souza et al. (2013) speculate that endurance training may inhibit Akt/mTOR/P70S6k pathway, which is highly correlated to increases in muscle protein synthesis. Molecular signaling is one area that trainers and coaches should consider if working with specialized athletes (e.g. powerlifting, bodybuilding). The molecular level is an area that requires further research on human subjects as most of the literature refers to animal studies.
The concurrent training literature revealed it could be a viable exercise modality for several populations. Recreational athletes or overweight individuals considering workout programs can utilize this training, especially if under time restraints. Lastly, it can be noted that if specialized athletes want to utilize some aerobic training without disrupting resistance training adaptations less volume and utilizing a cycle ergometer are viable alternatives (Alves et al., 2012).
Alves, J., Saavedra, F., Simão, R., Novaes, J., Rhea, M. R., Green, D., & Reis, V. M. (2012). Does Aerobic and Strength Exercise Sequence in the Same Session Affect the Oxygen Uptake During and Postexercise?: Journal of Strength and Conditioning Research, 26(7), 1872–1878. http://doi.org/10.1519/JSC.0b013e318238e852
de Souza, E. O., Tricoli, V., Roschel, H., Brum, P. C., Bacurau, A. V. N., Ferreira, J. C. B., … Ugrinowitsch, C. (2013). Molecular adaptations to concurrent training. International Journal of Sports Medicine, 34(3), 207–213. http://doi.org/10.1055/s-0032-1312627
Jones, T. W., Howatson, G., Russell, M., & French, D. N. (2013). Performance and neuromuscular adaptations following differing ratios of concurrent strength and endurance training. Journal of Strength and Conditioning Research / National Strength & Conditioning Association, 27(12), 3342–3351. http://doi.org/10.1519/JSC.0b013e3181b2cf39
Rhea, M. R., Oliverson, J. R., Marshall, G., Peterson, M. D., Kenn, J. G., & Ayllón, F. N. (2008). Noncompatibility of Power and Endurance Training Among College Baseball Players: Journal of Strength and Conditioning Research, 22(1), 230–234.http://doi.org/10.1519/JSC.0b013e31815fa038
Wilson, J., Marin, P., Rhea, M. R., Wilson, S., Loenneke, J., & Anderson, J. (2012). CONCURRENT TRAINING: A META-ANALYSIS EXAMINING INTERFERENCE OF AEROBIC AND RESISTANCE EXERCISES. Journal of Strength & Conditioning Research (Lippincott Williams & Wilkins), 26(8), 2293–2307.