Skeletal muscle adapts to the specific training imposed on the muscle. Therefore the mode, volume and intensity of exercise dictate the adaptions that occur in our muscles.
For example, different muscle adaptations occur whether one conducts endurance or resistance exercise on a regular basis. Some individuals focus on either one or the other (resistance vs endurance training) and some incorporate both types of training to get better at their sport or event.
Concurrent training is where athletes perform successive resistance and endurance training sessions. The scientific research suggests there are factors due to concurrent training that can prevent the outcome of interest. For example, performing resistance exercise following a tough cardio session may limit the strength and muscle gains over time [1, 2].
The cellular/molecular response (i.e. protein synthesis) to an acute concurrent training session hasn’t clearly been established by scientific research; hence the possibility exists that a concurrent training session may promote both myofibrillar and mitochondrial protein synthesis.
Basically, we don’t know if concurrent training can stimulate both protein synthesis in the skeletal muscle (causing increase in muscle size) and in the mitochondria (enhancing mitochondrial biogenesis, hence enhancing the “power plants” of our cells) at the same time.
We know that utilizing nutrient timing by consuming high quality protein (i.e. whey protein isolate) around resistance exercise enhances rates of muscle protein synthesis , and increases strength/muscle size. In addition, protein ingestion after endurance exercise can increase mitochondrion-related genes and enhance myofibrillar protein synthesis .
Of course, this is what we do as part of the metabolic precision nutrient timing around intense exercise. Until recently, there hasn’t been any research that investigated the effect of protein ingestion after a concurrent training session on the acute myofibrillar and mitochondrial protein synthesis rates in skeletal muscle.
A recent study examined the acute effects of whey protein ingestion on rates of myofibrillar and mitochondrial protein synthesis after a bout of consecutive resistance exercise and cycling .
- Postexercise whey protein ingestion decreases the expression of markers of muscle catabolism after a concurrent training session. These are markers that are elevated when we are in a catabolic (i.e., muscle breakdown) condition. Being catabolic is definitely not a good thing if we want to add lean muscle tissue and enhance our metabolism. Decreasing these catabolic markers from nutrient timing of whey protein is a really good thing because it shows these subjects were more anabolic after a concurrent training session than the control group who didn’t receive the whey protein.
- This research indicates that resistance exercise seems to generate a sufficient signal (i.e. response) to stimulate myofibrillar protein synthesis despite a subsequent bout of endurance exercise. This increase is similar to previous maximal levels observed when whey protein is ingested after resistance exercise only . Basically, the resistance exercise session still had a positive impact on protein synthesis despite the subsequent bout of endurance exerciser.
Findings from this study suggest consuming whey protein can be beneficial after successive resistance and endurance (concurrent) exercise by promoting myofibrillar protein synthesis and enhancing anabolism in muscle. It’s also suggested that postexercise whey protein ingestion may have potential to lessen the “interference” of endurance exercise on muscle hypertrophy and represents and important nutritional strategy for concurrent training. This research adds further scientific evidence on the power of utilizing nutrient timing as part of your metabolic precision eating plan.
Implications of this research
- Although this research demonstrated an acute benefit of nutrient timing by consuming whey protein after concurrent training; keep in mind this was an acute study and more research needs to be done over a long-term bases to gather more evidence. If your goal is to maximize muscle strength and size; it’s best to separate your FIRE and ICE sessions.
- If you or a client is a cross trainer and competes in events that inherently have strength and endurance tasks (e.g. Spartan races), they may conduct concurrent training to maximize their training time. It is crucial to utilize the power of nutrient timing immediately after a concurrent training session in order to maximize the training response from these sessions.
1. Wilson, J.M., et al., Concurrent training: a meta-analysis examining interference of aerobic and resistance exercises. J Strength Cond Res, 2012. 26(8): p. 2293-307.
2. Coffey, V.G., et al., Consecutive bouts of diverse contractile activity alter acute responses in human skeletal muscle. J Appl Physiol (1985), 2009. 106(4): p. 1187-97.
3. Koopman, R., et al., Protein ingestion further augments S6K1 phosphorylation in skeletal muscle following resistance type exercise in males. J Nutr, 2007. 137(8): p. 1880-6.
4. Breen, L., et al., The influence of carbohydrate-protein co-ingestion following endurance exercise on myofibrillar and mitochondrial protein synthesis. J Physiol, 2011. 589(Pt 16): p. 4011-25.
5. Camera, D.M., et al., Protein ingestion increases myofibrillar protein synthesis after concurrent exercise. Med Sci Sports Exerc, 2015. 47(1): p. 82-91.
6. Moore, D.R., et al., Differential stimulation of myofibrillar and sarcoplasmic protein synthesis with protein ingestion at rest and after resistance exercise. J Physiol, 2009. 587(Pt 4): p. 897-904.