Fitness vocab: time under tension

TERM: Time under tension

DEFINITION: Time under tension, or TUT, refers to how long muscle fibers work against resistance during a given exercise, explains New York City-based PROJECT by Equinox instructor Patrick McGrath, who created the new Equinox Band Burn class. All about increasing muscles’ time under tension, Band Burn will help you build a toned and lean body.

“Research has shown that muscle strength and endurance don’t happen based on just how much weight a person lifts, but also the total amount of time someone is working against that load, says Leah Friedlander, New York City-based manager of group fitness programming at Equinox.

By lengthening the amount of time your muscles work during any given exercise, you “completely fatigue the muscle,” McGrath says. You increase the structural damage to the worked muscle fibers and therefore, your body’s response to repair and strengthen them.

For example, if you’re doing resistance-band rows and you're just ripping the band towards your body and then letting it immediately snap back to its resting length, you can get in a lot of reps, meaning you move a lot of total resistance. But your TUT for that exercise is still low. However, by slowly rowing the band to your torso, pausing for a few seconds, and then inching the band back to start, you can increase your time under tension—and results—even if it means you can perform fewer reps. Similarly, knocking out 10 reps in 90 seconds will score you far more muscle-building results than performing 10 in 30 seconds. Adding in some partial-range-of-motion pulses can also increase how long you can keep your muscles working before they completely give out.

TRY IT: Increase your body’s time under tension with these four exercises, demonstrated by Daigi-Ann Thompson a group fitness instructor at Equinox in New York City, which are staples in Band Burn. Do them as a circuit, twice through on each side, with 60 seconds of rest in between. You’ll need a Theraband CLX and set of gliders.


Get down on all fours with your palms flat on the floor, shoulder-width apart, and a Theraband CLX looped around the base of your right foot and right forearm. From here, extend your right leg and left arm out away from you until they’re parallel to the floor. Keep your torso stationary as you do so, and eyes fixed on your moving hand. Pause, then crunch your arm and leg back to start. Perform for 60 seconds at a slow, controlled pace. Then hold isometrically at the top and pulse for 30 seconds for a final burnout. Switch sides.

Triple Lateral Lunge Shift

Stand with your feet double shoulder-width apart and hold one end of a Theraband CLX in each hand. Extend both arms straight out to your sides so you are pinching through your shoulder blades and the band is taut. From here, bend your left knee to lower into a quarter side lunge, simultaneously reaching your right hand toward your left foot and your left hand raising  overhead. Maintain tension in the band. Immediately switch sides. Perform for 3 minutes at a controlled pace.

Curtsy sweep + breaststroke

Stand with your right foot on the middle of a Theraband CLX and slightly bend your knee and hip for stability. Cross the ends over your foot and loop them around the backs of your hands, in front of you at waist height. Place your left foot on top of a glider, and extend it in front of you. From here, sweep your left foot in a wide circular motion behind you and to the side as far as possible. Simultaneously pull your arms out to the sides and slightly behind your body. Pause, then return to start. Repeat, performing for 90 seconds at a slow, controlled pace. Switch sides and repeat.

Army Crawl

Get into a low plank position on your forearms with the balls of your feet on a glider. Brace your core so that your body forms a straight line from head to heels. From here, maintaining a strong plank position, walk one forearm, then the other, forward, dragging your feet behind you on the glider. Walk your arms back to return to start. Perform for 60 seconds at a slow, controlled pace.

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