Your Personal Trainer may use elements of Concurrent training in your fitness plan. Concurrent training for the purpose of this article will entail training with the purpose of increasing hypertrophy, strength and general fitness. Other skillsets such as technique, coordination, judgement etc. which may be of significant value to many sports will be beyond the scope of this article.
The idea of being big, strong and fit has long been present in sports such as rugby for many years now. However, with the advent of CrossFit becoming popular amongst the general population, the appreciation of becoming more proficient in all aspects of fitness has gained widespread recognition. We are now seeing more powerlifters and bodybuilders engaging in more aerobic forms of exercise with the intent of improving other aspects of their physical capabilities, as well as marathon runners taking up resistance exercise. In many respects, this concurrent training may reduce injury risk and improve performance in their primary sport (Marques, 2005). Furthermore, it has been shown to have the added benefit from a health perspective with reduced morbidity in a multitude of populations compared to either alone (García-Hermoso and Ramírez-Vélez, 2018; Corso et al., 2016)
So is there a defined outline for how best to go about achieving all these simultaneously? Unfortunately, no. However, the research in the field is progressing and the accumulated anecdotal evidence from high level coaches and athletes has at least shone a light on some principles that we can work with.
It would be prudent to first discuss the interference effect; improving aerobic capacity versus increasing maximal strength require vastly different training modalities in many cases and lead to differing adaptations within skeletal muscle (Kraemer et al., 1995). This conflict can lead to attenuated improvements in both compared to training for either alone. So how do we go about mitigating this physiological tug-of-war? Luckily there is more than a few variables to play with dependent on the context of the individual.
Firstly, if you happen to be an individual who is an avid bodybuilder; resistance training 4-6x/week with significant volume, intensity and progressive overload. It is more likely you are operating near your recovery capabilities and are therefore already dealing with a significant source of physiological stress. Adding in several sessions of endurance training is likely to push you over the edge and limit any improvements or worse cause significant decrements to performance. So when deciding to add in added endurance training it is wise to scale back the resistance training and find the new limits of your recovery capabilities. The same is true in reverse for an endurance athlete taking up resistance training.
Next up is the separation between resistance and endurance training. Where possible training sessions should be separated by at least 6-8 hours where possible to allow a degree of recovery. This is for multiple reasons, already noted is the differing molecular stimuli and adaptations elicited by both forms and these are believed to interfere with each other to some extent (Nader, 2006). Another prominent reason put forward and to many may seem like common sense, is for example if you perform 30 minutes of cardiovascular training followed immediately a heavy lifting session you can’t apply the same intensity of effort as if you had performed it first. This is due to both central and peripheral factors such as central nervous system (CNS) fatigue (which may surprise some, is actually more predominant in lower intensity endurance exercise (Thomas et al., 2016)) and muscle glycogen depletion respectively. That being said, not everyone is willing to train two or more times per day. Fortunately, it has been found the interference effect is relatively localised to the muscles involved (Wilson et al., 2012). This means that if you were to perform an upper body session in the weights room for example, following it immediately with a lower-body predominant endurance exercise such as cycling instead of swimming would reduce the magnitude of the interference effect. That being said, even if may not be optimal it would be better to combine both forms than not do one at all, you aren’t going to lose a great deal of the benefits.
Another salient variable is the modality of endurance exercise. Where significant reductions in strength and hypertrophy have been found during concurrent training it has often been running that has been the form of endurance training used. Whereas, if cycling had been used instead the effect has been much less or even non-existent. Although there have been multiple hypothesised reasons behind this, I believe the most plausible factor to be the repetitive eccentric muscle contraction necessary during running that is not present in the concentric only action found in cycling (Koller et al., 1998). Eccentric muscle contractions have been found to inflict a much greater degree of muscle damage than concentric contraction and thus likely reduce the total volume of productive resistance training that can be performed.
Additionally, the intensity of endurance exercise has also been shown to be a factor. Multiple studies have found that high-intensity endurance training have been shown to have a lesser negative effect and potentially positive on hypertrophy and strength than low-intensity steady state in some instances. The argument is that high-intensity endurance training is a stimuli more similar to that of resistance training than low-intensity training and thus contributes to hypertrophy to a greater degree (Balabinis et al., 2003), it can be more difficult to recover from (Martinmäki et al., 2008). This leaves the door open for the possibility for a program that uses a higher volume of resistance training in combination with low-intensity endurance training or a mixture of both would yield different results. Especially given that both high and low intensity endurance exercise elicit similar adaptations but the molecular events that signal these adaptations have been shown to be somewhat different, thus potentially providing different avenues to improve the end goal (Laursen, 2010). However, setting up a volume standardised program as such would not be the easiest and as such has not been performed as far as I’m aware. It also has the additional downside of requiring significantly more time for potentially no additional benefit.
As you become more advanced and you are diverging further and further from your bodies natural homeostatic set-point, which sadly for those of interested is not that of an elite CrossFit athlete or similar. We have to start utilising more advanced techniques to continue improving down this path. Eventually we will reach a point where performing significant volumes of both aerobic and strength training will lead to a stagnation of improvements in both areas. This is where periodisation becomes of increasing importance. We cannot improve both simultaneously and therefore need to specialise in one facet while holding the other at maintenance. It is much easier to maintain a given level of size, strength and fitness than it is to further improve it. Therefore, if we have a need to further improve our aerobic capacity we must scale back either the volume, intensity or frequency of resistance training to simply maintain size and strength and to open up some of our recovery capacity for additional aerobic work to drive further positive adaptation.
Finally, for those interested in body composition it has been found perhaps paradoxically that higher intensity endurance led to greater decrease in body fat than did lower intensities during studies on concurrent training (Wilson et al., 2012). This again could be due to multiple factors, such as the exponential increases in metabolism after exercise with increasing intensity (Børsheim & Bahr, 2003).
In conclusion, although there are caveats and nuances to many aspects of this article. It is indeed possible to greatly improve hypertrophy, strength and endurance with the principles outlined in this article. For those who wish to learn more about the topic in greater detail, I’d highly recommend the works of Alex Viada founder of Complete Human Performance and author of ‘The Hybrid Athlete’. Similarly Ross Edgley a graduate of Sport & Exercise Science from Loughborough University who has amongst other things swam 2,000 miles around Great Britain in 157 days, ran a marathon pulling a 1.4 tonne vehicle and published ‘The World’s Fittest Book’ which details the principles of his training and others.
If you are seeking to improve or maintian your health, a Personal Trainer may be the perfect solution. Find a Personal Trainer on this platform for free. Simply search for a profile near you and contact the PT direct to begin your fitness journey.
Balabinis, C.P., Psarakis, C.H., Moukas, M., Vassiliou, M.P. and Behrakis, P.K., 2003. Early phase changes by concurrent endurance and strength training. Journal of Strength and Conditioning Research, 17(2), pp.393-401.
Børsheim, E. and Bahr, R., 2003. Effect of exercise intensity, duration and mode on post-exercise oxygen consumption. Sports medicine, 33(14), pp.1037-1060.
Corso, L.M., Macdonald, H.V., Johnson, B.T., Farinatti, P., Livingston, J., Zaleski, A.L., Blanchard, A. and Pescatello, L.S., 2016. Is concurrent training efficacious antihypertensive therapy? A meta-analysis. Medicine & Science in Sports & Exercise, 48(12), pp.2398-2406.
García-Hermoso, A., Ramírez-Vélez, R., Ramírez-Campillo, R., Peterson, M.D. and Martínez-Vizcaíno, V., 2018. Concurrent aerobic plus resistance exercise versus aerobic exercise alone to improve health outcomes in paediatric obesity: a systematic review and meta-analysis. Br J Sports Med, 52(3), pp.161-166.
Kraemer, W.J., Patton, J.F., Gordon, S.E., Harman, E.A., Deschenes, M.R., Reynolds, K.A.T.Y., Newton, R.U., Triplett, N.T. and Dziados, J.E., 1995. Compatibility of high-intensity strength and endurance training on hormonal and skeletal muscle adaptations. Journal of applied physiology, 78(3), pp.976-989.
Laursen, P.B., 2010. Training for intense exercise performance: high‐intensity or high‐volume training?. Scandinavian journal of medicine & science in sports, 20, pp.1-10.
Marques, M.A.C., 2005. Strength training in adult elite tennis players. Strength and Conditioning Journal, 27(5), p.34.
Nader, G.A., 2006. Concurrent strength and endurance training: from molecules to man. Medicine and science in sports and exercise, 38(11), p.1965.
Thomas, K., Elmeua, M., Howatson, G. and Goodall, S., 2016. Intensity-dependent contribution of neuromuscular fatigue after constant-load cycling. Medicine and science in sports and exercise, 48(9), pp.1751-1760.
Wilson, J.M., Marin, P.J., Rhea, M.R., Wilson, S.M., Loenneke, J.P. and Anderson, J.C., 2012. Concurrent training: a meta-analysis examining interference of aerobic and resistance exercises. The Journal of Strength & Conditioning Research, 26(8), pp.2293-2307.