Many people's exercise regimes are a combination of both strength and endurance activities. This is referred to as "concurrent training" and it is useful for many reasons. Not only does this type of training optimise cardiovascular and neuromuscular fitness at the same time, and have effectiveness for both weight loss and muscle building, but doing two types of workout in one session can be convenient, and many people find the variety keeps things interesting.
Although the majority of people doing concurrent training will knock over the more focus and muscle intensive strength training before zoning out to cardio, it's the rare person who has given a lot of thought to the order in which the exercises are performed. Exercise order seems inconsequential, but are we doing ourselves a disservice by not taking it into consideration?
A group of researchers saw this as a problem worthy of investigation, and decided to look into whether or not exercise order has any bearing on the post-exercise hormone profile. Fourteen men were recruited into this study, and were randomly allocated to one of two groups. One group took the more conventional route and knocked over their strength training before moving on to endurance (SE) while the other performed endurance exercise before strength (ES). Levels of various anabolic hormones were measured before and after these training sessions.
The scientists saw some clear cut results. Testosterone levels were up, on average, 52%, and levels of IGFBP-1 up 17% in the ES group, while the SE group did not register any significant changes in levels of these hormones after training. Levels of Cortisol and Growth Hormone rose significantly in both groups after exercise. These increases were statistically indistinguishable.
This presents some enlightening new information. People who are using concurrent training to put on muscle mass may be able to optimise their gains by strength training at the end of their session. This will then leave their body in an anabolic state during recovery, during which time the athlete has the opportunity to feed the muscles with a fast acting protein, like hydrolysed whey, to make the most out of their body's natural hormone spike.
Rosa C, Vilaça-Alves J, Fernandes HM, Saavedra FJ, Pinto RS, Machado Dos Reis V. Order effects of combined strength and endurance training on testosterone,cortisol, growth hormone and IGFBP-3 in concurrent-trained men. J Strength Cond Res. 2014 Jul 15.