Concurrent training is the amalgamation of two resistance training modalities (Strength + Endurance Training) into a single training cycle/block. Where both are performed concomitantly, which could be training these two modalities within the same day, same week or even every other week. Integrating these two modes of resistance together has been shown to reverse functional incapacities like Sarcopenia and several metabolic conditions like Type 2 Diabetes and Obesity.
Now, why would I say that? Well, whether we Barbell Squat or run 5 miles, at the end of the day our muscles are facing resistance from a variety of forces. May it be the external load of the barbell or the forces placed on ourselves during running. To put it simply, to resist the forces applied during any physical activity, our muscles produce tension to overcome these forces and thus cause movement. Now the intensity & magnitude of tension produced determines the adaptations caused.
The body responds to stimuli by adapting in a way which makes it robust to tackle similar stress stimuli. Acute bouts of resistance training of any kind lead to several molecular signalling responses and gene expressions which leads to protein accretion over time.
We know that strength training with adequate training volume and relative intensity builds muscle as long as we are subjecting those large threshold motor units to produce tension. This tension is sensed by our muscle cells which leads to a downstream cellular effect to cause muscle growth or as we call it hypertrophy, where muscle fibres or myofibrils are added either in parallel or an in a series fashion.
During an endurance training bout, skeletal muscles are subjected to lower intensity and longer duration contractions which do not require sufficient tension production. This provides the body with the required stimulus for it to adapt.
Doesn’t the principle of specificity apply? If we want to increase strength, we should strength train and get stronger by progressing over time with weight, or if we want to get faster and increase endurance, we must stick to just low-intensity aerobic activities.
That’s not true as there are always grey areas to cover. What about a person who has to develop both adaptations? An athlete?
Think American Football Players, Soccer, or even cricket for instance: These sports require the physical demand that revolves around maximizing feats of muscular adaptations like strength/power and endurance adaptations. Thus, aside from just a health perspective, dynamic training sessions including both aerobic and strength training are essential for athletic performance in a variety of sports.
Thus, the following video explains ways in which an athlete can amalgamate two training protocols (strength training + Endurance Training) into one training cycle.