Time under tension (TUT) is an expression that pops up from time to time in discussions about strength training. Charles Poliquin, an influential Canadian strength coach, coined this term in his eponymously-titled book The Poliquin Principles.
Before I explain the basic premise of time under tension, allow me to define a few terms.
Tension is the force used to contract a muscle. In this context, we’re referring to the force needed to move the weight used during exercise. Time is the period during a set when muscle(s) are under tension – the eccentric and concentric portions of the lift; it does not include the rest time at the top and bottom of the lift.
Coach Poliquin makes the claim that different training objectives – pure strength, hypertrophy, or strength endurance – are stimulated optimally by a different time under tension. For instance, hypertrophy is best achieved with a TUT of 30 to 70 seconds duration. The ideal time varies depending on the ratio of slow-twitch to fast-twitch muscle fibers and other factors.
| Pure Strength | Hypertrophy | Strength Endurance |
| 1-30 seconds | 30-70 seconds | 70-100 seconds |
As an example, consider a set of 10 reps of biceps curls. If the concentric and eccentric movements both take 2 seconds, the total time under tension for a single rep is 4 seconds. A set of 10 reps works out to a TUT of 40 seconds (although the total time per set is longer because of the tension-free pause between reps).
So, Charles Poliquin claims that the rep range is important, but so is the time spent actively contracting muscles during a set. Therefore, reps performed ballistically, instead of with a slow, controlled pace, are sub-optimal.
Whether this is, in fact, true, is unproven. What’s clear is that beginners should concentrate on proper form and progression, leaving concerns about TUT for later when progress begins to stall.
{ 2 comments… read them below or add one }
time under tension goes way back before poliquin try charles atlas
Charles Atlas hyped the concept of “dynamic tension”. This is somewhat different than “time under tension”. Atlas’ theory applies to isometric exercise while TUT applies to resistance training through a range of motion.
Since I’d love to expand this article and make it more useful for readers, I hope you’ll correct me if there’s something I’m failing to understand about Charles Atlas’ contributions to exercise theory. Thanks for the comment.