Pre-Workout Intake of High-Protein Products: Palatability and Gastrointestinal Effects of Milk vs. Yogurt

Background: Muscle mass is a fundamental component for overall health and physical performance. A combination of exercise and protein intake is the best way to enhance protein synthesis and develop muscle mass. In order to promote protein intake, palatability and gastrointestinal symptoms should be considered when evaluating dairy products, such as milk or yogurt, as a viable, convenient and tolerable option before exercise. Objective: To compare the palatability of two protein-rich products before starting resistance exercise and potential gastrointestinal symptoms that may arise during exercise after their consumption. Methods: In a randomized, crossover study, 30 physically active individuals visited the laboratory on two occasions. During each visit, they consumed ≈25 g protein in the form of milk (500 mL) or yogurt (200 mL) and performed a resistance training session. The palatability of the products was assessed after consumption and perceived gastrointestinal symptoms were measured before product intake, after intake, at the middle and at the end of the exercise session. Results: Sweetness was higher for milk (7.73 ± 1.36) than for yogurt (7.13 ± 1.48) (p = 0.034). Overall acceptance was higher for milk as well (7.63 ± 1.09 for yogurt and 7.97 ± 0.85 for milk) (p = 0.048). Regarding GI symptoms, abdominal bloating and belching showed differences between products, being greater with milk, while thick saliva, reflux and nausea showed differences among measurement times. Overall, reported GI symptoms were few, and they were mostly mild for both products. Conclusions: Both products showed good acceptance and tolerance and therefore, can be considered good options for protein intake prior to resistance exercise.