With chocolate milk suggested as a possible post-workout drink, with both protein and carbohydrate, researchers set out to determine the acute changes in testosterone and isometric strength with some post-exercise chocolate cow’s and goat’s milk.1
Twelve, healthy college-aged men performed a back squat consisting of 5 sets of 8 reps over three separate exercise trials. After each trial, they drank either 1 cup of cow’s milk, 1.5 cups of goat’s milk, or 1.5 cups of water, which was used as the control condition.
Then, they used the isometric mid-thigh pull to test strength, and a salivary test for circulating testosterone levels. They did not find any differences in changes in isometric strength between the condition, but they did with testosterone.
There was little change in the control condition 60- and 120-minutes post-exercise. However, testosterone in both the goat’s milk condition, and the cow’s milk condition was significantly lower than the control group.
So, the authors conclude, “Compared to control, both cow’s and goat’s low-fat chocolate milk resulted in blunted postexercise salivary testosterone.” Which was also found in previous studies that measured testosterone in the blood.
However, it is possible that “the similar decrease in testosterone levels observed in the present investigation for both the chocolate goat’s and cow’s milk might be associated with similar increases in testosterone uptake.”
In other words, we do not know if the milk is lowering testosterone produced after the exercise or if it is promoting more uptake from the saliva and blood.
The premiere review on the subject supports that resistance exercise acutely increases testosterone in men, especially large muscle mass exercises and high volume, but “Carbohydrate/protein supplementation has been shown to limit testosterone response to resistance exercise.”2
As for now, it does not look too good for the use of milk after a weight training, but future research will keep us moooving in the right direction.
- Bellar, D., LeBlanc, N. R., Murphy, K., Moody, K. M., & Buquet, G. (2016). The Impact of Chocolate Goat's and Cow's Milk on Postresistance Exercise Endocrine Responses and Isometric Mid-Thigh Pull Performance. Journal of Dietary Supplements, 13(5), 560-569.
- Kraemer, W. J., & Ratamess, N. A. (2005). Hormonal responses and adaptations to resistance exercise and training. Sports Medicine, 35(4), 339-361.
- Demonstration of Isometric Mid-Thigh Pull - Australian Institute of Sport and Port Adelaide FC. https://www.youtube.com/watch?v=3BimzkoaFis