Many people choose to take a caffeinated, protein-based supplement before working out – and new (often expensive) products are hitting the shelves every day. Previous studies have demonstrated the positive effects of such multi-ingredient pre-workout formulations (PREW) on strength, power output, muscular endurance, and muscle mass. However, a new double-blind, randomised control trial published in the Journal of the International Society of Sports Nutrition has suggested they may not be any more effective than a carbohydrate-only supplement.
What Did the Study Find?
The 43 middle-aged, physically active individuals who completed the study were randomly assigned to one of two groups: the caffeinated, protein-based pre-workout supplement group or the carbohydrate-only supplement group. Each group took 30g of their assigned supplement, mixed with 400ml of water, 15 minutes before each workout session. Measurements of fat and fat-free mass, waist and hip circumferences, muscle thickness, strength, power output, and muscle endurance performance were collected before and after a six-week resistance training programme performed three times per week.
