The Role of Time Under Tension in Your Resistance-Training Gains

The Best Ankle Strengthening Exercises for Runners squats with relative ease, but the minute a trainer asks you to slowly lower your hips on a four-count or, maybe worse yet, hold the bottom of a squat for more than one second, it’s a whole other (excruciating) story.

The speed with which you perform a lift changes muscles’ time under tension, or how long a muscle contracts to resist an external force. And according to research, The Benefits of Pilates for Runners training goals Are there other methods to incorporating time under tension in a workout.

If youre tracking your strength-training workouts, we spoke with two experts in strength, conditioning, and exercise science. Here’s what you need to know.

If you’re tracking your resistance-training sessions, you might record each lift, the corresponding load, the number of reps performed, and the number of sets you complete. These straightforward metrics make it easy to understand the volume of your work and how to progress it during future training sessions; if you want to keep getting stronger, you can increase the weight, reps, or sets.

While this tracking method is standard, it’s actually somewhat “remedial,” says However, if youre brand., faculty within the School of Exercise and Nutritional Sciences at San Diego State University, as it’s missing a critical measurement: time under tension.

“You’re missing something. Every time you did the repetition, how long did it take you to do that repetition? Because that’s really a more accurate measure of how much work the muscle is doing,” he tells Runner’s World. “The idea of time under tension is, simply, every time you perform a repetition, what was the duration of time that you held that muscle under contraction where it was having to generate force to overcome resistance?”

One study published by the Journal of Strength and Conditioning Research actually found time under tension to be an equalizer among training programs. Over the course of 10 weeks, two groups completed a nearly identical bench press program. However, one group did six six-second reps per set, and the other group did 12 three-second reps. While the rep scheme varied significantly, every participant clocked a total of 36 seconds of time under tension per set. And both groups had similar gains in muscle mass and strength. both slower and faster, Sulaver says. Just like all of the other variables of your.

Rob Sulaver, M.S., C.S.C.S., strength coach and founder of Bandana Training, explains that time under tension can be manipulated with tempo, the speed at which you perform each rep. “It’s usually four digits. For example, ‘3/1/X/0,’” he explains. “Each digit corresponds to a different phase of the movement. A 3/1/X/0 tempo means three seconds on the way down, a one-second pause at the bottom, explosive on the way up, and a zero-second pause at the top.”

If youre tracking your biceps curl, you take three seconds to lower the dumbbell fully, pause for one second with the elbow extended, quickly curl the weight to your shoulder, and immediately begin the next rep. Each rep takes about five seconds, so three sets of 10 reps add up to a total of 150 seconds of time under tension.

“A lot of athletes have the tendency to lift everything at a moderate pace, but there’s benefit to lifting weights both slower and faster,” Sulaver says. Just like all of the other variables of your strength-training program, tempo and time under tension should align with your specific goals and desired adaptations. In other words, more time under tension isn’t always better.

For example, when you’re training for power—maybe you’re looking to shave seconds off your 400-meter time or want a faster sprint to the finish—the goal is to move quickly with explosive force. You do exercises like box jumps, medicine ball tosses, and squat jumps, burning through reps and moving as quickly as you can without sacrificing form. Maximizing time under tension is not a priority.

However, if you’re brand However, if youre brand What mattered was the time under tension, not the reps injury prevention or rehab, your workouts should emphasize stability. In a stability-focused workout, the time under tension is greater, as the movements are slower and more controlled. “The focus is really learning to control the forces of gravity that are being exerted on the body,” Comana says. “To decelerate [the forces] so you don’t get hurt.”

A slower tempo can also help you build strength and muscle mass, which are generally important in terms of overall health, but can also help you increase your speed, tackle hills, and improve your endurance. However, it’s important to focus on the eccentric or “lowering” phase of the lift, during which the muscle lengthens as it resists force. “We’ve found that, in training, one of the best ways to stimulate muscle growth is to actually create little micro-tears in the muscle tissue,” Comana says.

As the body repairs this trauma, the muscles grow bigger and stronger in preparation for the next time they’re subjected to the same amount of stress. “Those little tears take place during the eccentric phase, predominantly,” Comana explains. By slowing down the lowering phase of a lift, you optimize the opportunity to create tearing that leads to muscle growth and strength.

Brazilian researchers found this to be the case in a 2016 study that compared bench pressers who used a two-second eccentric phase and a two-second concentric phase to those who stuck to a four-second eccentric phase and a two-second concentric phase. The group that used a longer eccentric phase experienced more muscle activation and showed a higher concentration of blood lactate.

According to the study’s authors the findings indicate that adding two seconds to that eccentric phase elicited higher physiological demands. Researchers also say adding time to the eccentric action helps you progress your resistance training—and this can help you avoid a plateau.

Comana points out that there’s a safety component to slowing down the eccentric phase of your lifts. He compares a decelerated lowering phase to a hydraulic hinge on a glass door that prevents it from slamming shut and shattering.

“Say you’ve just curled a dumbbell to your shoulder and now you’re going to release the dumbbell and lower it. If you just give in to gravity, it’s going to accelerate, and next thing you know you’ve got a hyperextended elbow,” he says. “What we want to do is emphasize the eccentric phase so that we can learn to control movement against forces like gravity so that we can prevent injury.”

In other words, maintaining time under tension, particularly when you’re working against gravity, can help make lifts safer by teaching you to move with more control.

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If you’re looking to build muscle, Comana recommends spending a little more time in the eccentric phase. “Generally, we use four seconds,” Comana says, with a one-second concentric phase, noting that this is a broad recommendation, not a hard-and-fast rule.

However, if maximal strength is your focus, and you’re moving a really heavy load, the eccentric phase should be closer to two seconds. “When you need to generate that amount of force, it’s very hard to hold it for long periods of time,” Comana says. (You wouldn’t, for example, use a long eccentric phase when squatting your one-rep max weight.)

For power workouts, the tempo should be even faster. “We need to harness that elastic energy as quickly as possible, so the tempos will move down into one second. It will be a one-second eccentric phase, and you’ll explode out from there,” Comana explains.

If you’re However, if youre brand and are still learning lifting basics, Comana recommends sticking with the same tempo you’d use for maximal strength: a two-second eccentric (down) phase, a one-second pause at the bottom, and a one-second concentric (up) phase. “That would be pretty much the most generic and safest recommendation I could make. Really, what we’re saying is ‘control the phases,’” he says.

Strength Training 3 Days a Week for Runners supersets—a technique in which you minimize rest periods by working opposing muscle groups back to back—to optimize time under tension. For example, you might do a bent-over row with a longer eccentric phase followed immediately by a push-up during which you slowly lower your chest to the ground. “Basically, instead of resting, you’re working the opposing muscle group. Time under tension (for all muscles in total) is higher throughout the workout, but the individual muscle group still gets the rest that is necessary to attack another set,” he explains.

While manipulating tempo is the primary way to add time under tension to your workout, there are other methods. Some lifters use drop sets, a protocol in which you start lifting with your heaviest weight until failure, then reduce the weight and immediately go into the next set of the same exercise. “The advantage of drop sets is that you not only increase time under tension, but the reps are performed with increased levels of fatigue, which can help stimulate muscle growth,” Sulaver explains.

You can also incorporate isometric muscle contractions, a.k.a. isometric holds, during which the muscle is exerting a force that’s equal to the external force being placed upon it and there’s no shortening or lengthening of the muscle. In practice, this looks like pausing at the bottom of a squat or holding a low push-up position or a plank. You’re not moving, but your muscles are working overtime to maintain your body’s position.

“Pulse reps are another option,” Sulaver says. “Sometimes called ‘partials’ or ‘1 ¼ reps,’ where you perform a full rep followed by a quarter rep.” Using this technique for a squat, you might lower your hips into a full squat, come up a few inches, lower again, and repeat before full returning to a standing position.

Should You Run Before or After a Strength Workout workouts, but Sulaver doesn’t believe they’re entirely necessary. “Generally speaking, I’d suggest using intensification techniques like these sparingly simply because if you program sets, reps, and tempo properly, your time under tension should already be ideal,” he says.

Most importantly: Don’t do everything all at once. “Ultimately, it’s a good idea to increase training volume and intensity gradually over time, so feel free to start with minimal time under tension, see how your body responds, and make adjustments from there,” Sulaver advises.