In the realm of athletic pursuits, the convergence of strength and endurance training has long posed a challenge for those seeking to push their physical limits. For individuals who aspire to excel both in the weight room and on the race track, the concept of concurrent training emerges as a fascinating and multifaceted approach. Striking a harmonious balance between the demands of strength building and the requirements of endurance sports is a pursuit that demands careful planning, strategic programming, and a nuanced understanding of the physiological intricacies involved. In this exploration of concurrent training, we delve into the art of synergizing these seemingly disparate realms, uncovering the science behind the approach, the potential benefits, and the vital considerations essential to those aiming to embrace the duality of strength and endurance in their athletic journey.

Concurrent Training involves combining aerobic exercise with resistance training, and is a widely researched and controversial topic in exercise science. Numerous studies have explored the effects of concurrent training on various fitness outcomes, such as strength, hypertrophy, power, and endurance. The complexity of concurrent training lies in balancing the potentially conflicting adaptations and optimizing training protocols to achieve desired outcomes.

Will Endurance Training Negatively Impact Resistance Training?

Before jumping in, we would like to share a systematic review and meta-analysis from Petre et al. (2021) that explores the effects of concurrent training on strength gains in trained and untrained lifters. This research is appropriate and relevant because she is not considered a trained lifter. This extensive study found that concurrent training leads to smaller lower-body strength gains (but not that significant) than solely performing resistance training only among trained lifters. However, the results suggest that concurrent training does not hinder gains in moderately trained or untrained lifters.

One notable finding from the study is that even for trained lifters, concurrent training may not hinder gains as long as endurance training and strength training are conducted in separate training sessions, with a minimum separation of three hours between the two. This might mean that careful programming and scheduling of training sessions can potentially mitigate the adverse effects of concurrent training on strength gains in trained individuals. Also, the authors mention that although the impairment was present among trained participants, the impairment was moderate.

One potential explanation for the disparity between untrained and trained individuals could be that trained individuals have already experienced significant adaptations and require more targeted training to achieve further performance improvements. Another explanation might be that a trained athlete is likely pushing the intensity in both their endurance and resistance training sessions. We might suspect that a new lifter will not push their sessions as hard, and we know a higher overall workload may increase the risk of prolonged catabolic* states. It could negatively impact muscle adaptations, mainly if endurance and resistance training sessions are performed near each other.

*Catabolic state is when our body is breaking down nutrients or stored energy. This could be the break down of body fat, muscle, bone or nutrient reserves.*

Should I Do Endurance Training Right After Resistance Training?

This finding is consistent with recommendations from Tomiya et al. (2017). This study compared two groups of training approaches, one group performed cardio immediately after strength training and the other performed cardio on separate days. Both groups achieved similar gains in strength. However, the group that performed cardio on separate days experienced more than two times greater hypertrophy* than the group that performed cardio immediately following their lifting sessions. If we want to program cardiovascular exercises with strength training, we recommend scheduling them on separate days if possible. Again, this is a relevant study because it included untrained lifters. We may still make gains if we complete both in one session, but this study suggests that progress may come at a slower rate compared to separating cardio and lifting days.

*Hypertrophy refers to an increase in muscular size achieved through exercise.*

These findings are also consistent with the study from Sabag et al. (2014), which examined the effects of concurrent training, and results showed that concurrent training did not significantly impact upper body strength or hypertrophy when compared to resistance training alone. We can confidently recommend that individuals engaging in concurrent training can likely counteract potential adverse effects on lower body strength and hypertrophy by separating cardio and lifting into different sessions.

How Does Endurance Training Impact Hypertrophy?

Additional research from Schumann et al. (2012) investigated the differences between concurrent training and resistance training in hypertrophy and strength gains. The findings revealed no significant differences in hypertrophy and strength between the two training methods. However, it was observed that explosive strength (power), which involves rapid force production, was negatively affected by concurrent training. This is consistent with more recent findings and suggests that individuals focusing on developing explosive strength may need to consider the potential impact of concurrent training on their performance (Dragutinovic et al., 2022). If we are focused on power goals, aerobic exercise may negatively impact this. It sounds like this is not the case, as she is interested in hypertrophy.

When prioritizing hypertrophy as a primary goal, research suggests that High-Intensity Interval Training (HIIT) may be more favorable than moderate or low-intensity cardio (Sabag et al., 2018). However, it is essential to note that HIIT can be more demanding in terms of recovery. This becomes particularly relevant when planning a high-volume hypertrophy-focused training block, as adequate recovery becomes crucial. 

Conclusions:

So, while aerobic exercise can potentially attenuate hypertrophy and strength gains, the extent of this interference is influenced by various factors such as timing, overall dosage, and your individual training status. However, it is essential to note that this interference should not be a cause for excessive concern. We can still make significant gains with running and lifting. And by taking precautionary measures, we can minimize any potential adverse outcomes.

We can reduce interference by:

1. Separating cardio and lifting sessions by 24 hours, and if not possible, at least by 3-6 hours (newer research suggests 3).
2. Complete resistance training first if performed on the same day.
3. Managing overall dosage of lifting volume and cardio.
4. If preparing for an endurance competition, tapering resistance training appropriately (or vice versa).
5. Allowing for 1-2 days for complete recovery per week.

 

References: 

Dragutinovic, B., Feuerbacher, J. F., Jacobs, M. W., Bloch, W., & Schumann, M. (2022). Acute effects of concurrent high-intensity interval cycling and bench-press loading on upper- and lower-body explosive strength performance. International Journal of Sports Physiology and Performance, 17(7), 1077–1084. https://doi.org/10.1123/ijspp.2021-0571

 

Petré, H., Hemmingsson, E., Rosdahl, H., & Psilander, N. (2021). Development of maximal dynamic strength during concurrent resistance and endurance training in untrained, moderately trained, and trained individuals: A systematic review and meta-analysis. Sports Medicine (Auckland, N.Z.), 51(5), 991–1010. https://doi.org/10.1007/s40279-021-01426-9

 

Sabag, A., Najafi, A., Michael, S., Esgin, T., Halaki, M., & Hackett, D. (2018). The compatibility of concurrent high intensity interval training and resistance training for muscular strength and hypertrophy: a systematic review and meta-analysis. Journal of Sports Sciences, 36(21), 2472–2483. https://doi.org/10.1080/02640414.2018.1464636

 

Schumann, M., Feuerbacher, J. F., Sünkeler, M., Freitag, N., Rønnestad, B. R., Doma, K., & Lundberg, T. R. (2022). Compatibility of concurrent aerobic and strength training for skeletal muscle size and function: An updated systematic review and Meta-analysis. Sports Medicine (Auckland, N.Z.), 52(3), 601–612. https://doi.org/10.1007/s40279-021-01587-7

 

Tomiya, S., Kikuchi, N., & Nakazato, K. (2017). Moderate intensity cycling exercise after upper extremity resistance training interferes response to muscle hypertrophy but not strength gains. Journal of Sports Science & Medicine, 16(3), 391–395.