Concurrent Training … the concept of simultaneously training to improve in sports that require very different exercise adaptations.
Classically concurrent training has been defined and studied in terms of resistance and endurance training. In reality many sports incorporate an element of concurrence … from rugby league, where the players must be strong and fast and last an 80 minute game, to CrossFit, where the very definition of the sport is to maximise the ability to do anything over any time domain.
Theoretically you can see how the ‘opposite’ ends of the fitness spectrum could support one another. Say if you are a cyclist … if you weight train your legs you may build more leg muscle strength and power, helping you to power the uphill climbs on the bike.
In practice the situation is a little more murky. It seems we can see an ‘Interference Effect’ from concurrent training. This is where we do not see as great an improvement and gains in each sport as we might see if we were training just one alone.
Why is this, and can anything be done about it?
I guess the short answer is “we only know some of the story, and potentially yes but to what extent is still unknown”. I am not going to dive into all the ‘ifs’ and ‘buts’ in this blog. I am going to give a brief overview of some variables, and then focus on some of the things we think may be important from the nutrition perspective.
As we currently understand it, the following are factors that impact the extent to which interference is likely:
Training status: the more well trained an individual, the more likely it is that an interference effect will be observed.
Training load: the greater the training load, the more likely it is that an interference effect will be observed.
Session spacing: the closer together the training sessions, the more likely it is that an interference effect will be observed.
Particularly focussing on the latter two, this gives some hint that fatigue and recovery may be big factors in the interference effect. And this could certainly be backed up by what we see at the level of the signals we see in muscle cells after concurrent training.
We can think of fatigue and recovery having an effect both on the quality of our subsequent training sessions (fatigue = poorer performance = less effective training stimuli = don’t get as fit / fast / strong) and our adaptation to our training (can’t adapt as well = don’t get as fit / fast / strong).
Indeed, studies have shown that neuromuscular and residual fatigue can reduce training performance in a subsequent session, and we know that under recovery certainly has an impact on adaptations to training.
So what does this mean for nutrition?
A few things to consider, particularly if you are regularly undertaking both types of training on a single day …
Energy Intake: this is critical!! The more you train, the fewer hours you have to eat in and the more calories you need. You need enough energy to maximise your training, to ensure you can recover and adapt AND for your body to still keep doing all it needs to stay healthy (see my recent blog on ‘What does food do’ for the consequences of not achieving this).
Macronutrient Split: there is an emphasis on slightly different macronutrients, depending on the sport you participate in. Consider the sports you do, the recommendations for that sport and then how you can balance the needs of each within your total energy intake.
Meal Timing: concurrent training is likely to be a situation where meal timing becomes of importance. Things like: after a session aim to consume at the very least protein and carbohydrates at a sufficient rate to enable rapid recovery and refuelling for your next session. Consider ensuring protein availability overnight with a pre-bed protein feed to further support overnight recovery. Carefully time fat and fibre intake to avoid gut issues during training. And if you are a fan of Train Low strategies (training with low carbohydrate availability) carefully evaluate whether the potential pros outweigh the potential cons of adding additional stress and periods of low energy availability with the concurrent training load you are undertaking.
So there we have it: concurrent training may support your sport, it may be your sport, and there are factors to consider from a nutrition perspective to help ensure you get the most from it. Oh, and most importantly, there is still a lot to learn so keep your eyes peeled for what new discoveries emerge over the coming years!!
Here is a great podcast from the Institute of Performance Nutrition on the subject, with Dr. Laurent Bannock and Dr. Jackson Fyfe: