During the Gaspari SuperPump trial, subjects ingested one serving of the bodybuilding supplement 30-minutes before starting the workout. During the placebo trial, subjects drank water. The workout consisted of 10 sets: 5 sets for the biceps and 5 sets for the triceps. All weights, reps and rest periods were tightly controlled and kept the same from one trial to the next. That way, any differences seen would be due to the supplement. Changes in lean mass (muscle) and body fat were measured with “gold standard” and one of the most sensitive tools available: dual-energy x-ray absorptiometry (DEXA).