TUT simply refers to the amount of time the muscle is resisting weight per set of an exercises. For optimal hypertrophy (muscle gain) it is suggested that we need between 40 – 70 seconds TUT in each set. In my experience many weight trainers aren’t hitting anywhere near that, instead sets usually last between 15 and 30 seconds. All that would be required is that these individuals simply slow down on the eccentric phase of the exercise (while the muscle is contracting and lengthening at same time). A good example would be the barbell bench press, start by taking the weight off the rack then slowly lowering the bar for 3 seconds (eccentric phase), hold just above the chest for 1 second and then press back up for 1 second, the total TUT of this rep would be 5 seconds. Complete 10 reps at this tempo and you achieve 50 ‘muscle building seconds’, time under tension, in this set.