The principle of “specificity of training” describes how your muscles adapt to a specific training imposed on them. Basically, 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, example powerlifter vs marathon runner) and some people utilize both types of training to get better at their particular sport or event (e.g. football).


Concurrent training

Concurrent training is where athletes perform successive resistance and endurance training sessions. Scientific research suggests there are variables occurring when conducting concurrent training, which can prevent the outcome of your desired training goal.

For example, performing resistance exercises 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 (responsible for an increase in muscle size) and in the mitochondria (which enhances mitochondrial biogenesis, hence enhancing the “power plants” of our cell) at the same time.

Nutrient timing

We know that utilizing nutrient timing by consuming high quality protein (i.e. whey protein isolate) around resistance exercises enhances the rate of muscle protein synthesis [3], and increases the strength/muscle size.

In addition, ingesting protein after an endurance exercise can increase mitochondrion-related genes and enhance myofibrillar protein synthesis [4].

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.

Recent research

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 exercises and cycling [5].

enhance training result_2Main findings

• Ingesting whey protein post-exercise 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 that these subjects were more anabolic after a concurrent training session than the control group who didn’t receive the whey protein.

• This research also 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 [6]. Basically, the resistance exercise session still had a positive impact on protein synthesis despite the subsequent bout of endurance exercise.


Findings from this study suggest that 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 long-term studies need to be conducted to gather more evidence.

If your goal is to maximize muscle strength and size; it’s best to separate your resistance and cardio sessions.

• If you are a cross trainer and compete 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.

Connect with WatchFit Expert Dr. Paul C. Henning PhD, CSCS, CISSN


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.

WatchFit Experts change lives!

And they can do the same for you.


Pollyanna Hale Health and Lifestyle coaches
Lost 13 Kg in Total
Mel, 32y Location: London, United Kingdom Working with Pollyanna changed everything. I lost 13kg, got toned and have more energy than ever! Get same results!


Chriz Zaremba Fitness Consultant
Lost 45 Kg in Total
Chris, 50y Location: London, United Kingdom Lost 45kg after the age of 50 and now competes and wins physique competitions and runs marathons Check our weight loss plans