(12-16-2012) Strength training is a very effective means to increase concentrations of hormones like testosterone and cortisol. These hormones are believed to be one of the important factors responsible for training related adaptations in our muscles. Many athletes are therefore interested in ways to optimise the production of these hormones. A common question is what order of training leads to optimal results? Performing strength training first followed by endurance training or vice versa? Scientists from the University published an article this month investigating the hormonal effects of training order in the Journal of Strength and Conditioning Research. So what is better for muscle growth: Cardio followed by strength training or strength training followed by cardio? Find out below.

What have the researchers done?

The researchers recruited 10 young men who regularly performed strength training. Prior to the study, subjects were tested for maximal strength in four exercises and endurance on an exercise bike. Afterwards all subjects performed two training sessions in random order. To minimise the influence of the previous training session as much as possible the exercise sessions were seperated by seven days. The training sessions differed in order of cardiovascular and strength exercises. Strength training consisted of bench press, squat, lat pulldown and leg extension. The subjects performed tree sets of eight repetitions in each exercise at 75% of 1RM with 90 seconds rest between sets. Cardio training consisted of 30 minutes of cycling on an exercise bike. The intensity of the cardio training was set at 75% of the maximum heart rate. Before and after training and at the transition between strength and cardio training, blood samples were taken. The blood was analysed to determine differences in blood concentrations of testosterone and cortisol.

What were the results?

The effects of different training sequences on testosterone and cortisol are shown in the figures below.

Figure 1: Effects of training order on testosterone production

Figure 2: Effects of training order on cortisol production

Testosterone concentration increased by 41.4% after the cardio-strength sequence, compared to only 3.3% in the strength-cardio sequence. On all other times, no significant differences in testosterone or cortisol concentration in the blood were found between the different exercise orders.

What did the researchers conclude?

Although the researchers are careful with their conclusion, given the small number of subjects, they argue that a training starting with cardiovascular exercise followed by strength training results in a higher concentration of testosterone afterwards. This, according to the researchers in the longer term leads to a greater increase in muscle mass.

What does this mean in for me?

An average amount of cardio performed before strength training has no adverse effects on muscle growth, and may even lead to better results.

Reference:

-Cadore, E. L., Izquierdo, M., dos Santos, M. G. et al. Hormonal Responses to Concurrent Strength and Endurance Exercise Training with Different Orders. Journal of Strength and Conditioning Research, 2012, 26, 12, 3281-3288.