The Impact of Chocolate Goat's and Cow's Milk on Postresistance Exercise Endocrine Responses and Isometric Mid-Thigh Pull Performance

Abstract

The present investigation examined the effects of chocolate cow's and goat's milk on endocrine responses and isometric mid-thigh pull performance post back squat exercise. Twelve college-aged males volunteered to participate and reported to the lab on four occasions. The first visit included anthropometric measurement, one-repetition back squat (1RM), and familiarization with the isometric mid-thigh pull assessment (IMTP). During the subsequent three visits, five sets of eight repetitions of the back squat exercise at 80% of 1RM were performed. For these trials, the participants performed an IMTP and gave a saliva sample prior to, immediately after, 1 hr and 2 hr post exercise. After exercise, a treatment of low-fat chocolate goat's milk (355 ml, 225 kcal), low-fat chocolate cow's milk (355 ml, 225 kcal), or control (water 355 ml, 0 kcal) was given in a counterbalanced order. Saliva samples were analyzed for testosterone, cortisol, and dehydroepiandrosterone (DHEA). Cortisol and DHEA hormone were unaffected by exercise; however, testosterone values did increase significantly post exercise. For IMTP, there was a significant main effect for time (F = 8.41, p = .007) but no treatment or interactions effects. N changes were noted post supplementation for cortisol or DHEA, but testosterone was found to be significantly reduced in both diary treatments compared to control (F = 4.27, p = .022). Based upon these data, it appears that a single treatment of chocolate goat's or cow's milk results in similar endocrine alterations but both fail to enhance postexercise isometric strength following resistance exercise.

A2 Milk Enhances Dynamic Muscle Function Following Repeated Sprint Exercise, a Possible Ergogenic Aid for A1-Protein Intolerant Athletes?

“…Similar reductions in loss of short-term isotonic power output following EIMD have been observed with beetroot juice ingestion, with no further beneficial effect on isometric strength [ 1 , 68 ]. Likewise, a single treatment of either cows or goats chocolate milk revealed no benefit in 2-h post-resistance exercise isometric strength assessed through mid-thigh pull performance [ 69 ]. Thus, perhaps a dynamic movement involving the stretch-shortening cycle is required to fully elucidate milk’s ability to attenuate EIMD, rather than a non-lengthening muscle contraction.…”