Is time dead under tension? New research shows the best rep tempo for muscle growth

The study discusses the repetition tempo of two to eight seconds as a recommended range for maximizing muscle hypertrophy during resistance training. The researchers emphasize that while several studies suggest including both eccentric (lengthening) and concentric (shortening) phases in each repetition, the specific duration of each phase is less important as long as the total repetition duration is in the range of two to eight seconds.

Overall, the studies discussed in the paper suggest that:

• Hypertrophy can be achieved with rep durations between two and eight seconds.
• There is no clear evidence to support the notion that extending the eccentric or concentric repetition phases beyond this two to eight second range would result in greater hypertrophy.
• Both faster concentric and slower eccentric phases may contribute slightly to greater muscle growth, but there is no concrete evidence for a specific duration of each individual phase.

One of the researchers, Jeff Nippard, explains: “Each repetition you do should last two to eight seconds.” This means you can do anything from a positive second for a second and a negative second to a positive second for a second and a negative second of seven seconds. The specific tempo doesn’t seem to be that important, just controlling the negative and not just letting the weight fall freely. And cheat reps seem like a bad idea, but there’s no study comparing ego lifting to strict form lifting yet. That’s the study we’re going to do next.”

What does this mean for us?

As long as a total rep time of two to eight seconds is maintained, muscle growth is more likely to occur – so there is no need to sweat over exact tempo durations to achieve muscle growth. The most important thing is that you adapt it to your needs and goals. You can check out our guide on speed here.

Different exercises are better suited to different repetition durations. For example, a shorter eccentric tends to be suitable for traditional deadlifts, while a longer eccentric is suitable for Romanian deadlifts. If your goal is to gain strength and athleticism, shorter concentric and eccentric phases may be preferable to longer duration reps. Heavier weights are also more manageable with shorter rep times, so this also needs to be taken into account.

But what about time under tension?

Research colleague Dr. Milo Wolf points out that time under tension may be more overrated than previously thought, but admits there is some truth to it. “If you ignore the time under tension or the total duration of your set, you might conclude that a one-rep set is a great way to build muscle,” says Wolf. However, he emphasizes that the benefits of focusing on time under tension end there, citing evidence that has analyzed which rep ranges are most effective for muscle growth. “The conclusion they have come to is that sets of around 5 to 50 repetitions are equally effective for building muscle, provided you complete that set close to failure.” “Beating failure seems to be more important than the pure maximization of time under tension.”

Citing other work on rep tempo, it concluded that while a slightly more controlled eccentric or lowering phase and a slightly more explosive concentric or lifting phase might optimize hypertrophy based on some preliminary evidence, most evidence suggests that one A wide variety of repetition tempos are equally effective for building muscle. “In fact, for hypertrophy, they recommend a set duration or time under tension per set of 20 to 70 seconds,” says Wolf.

Wolf concludes, “I guarantee you that if you do between five and 50 reps, you’ll be within that range unless you’re doing incredibly fast.” There’s no need to focus on time under tension and slowing things down a ton. Just use a reasonable rep range – usually 5 to 12, with some higher rep numbers in your program for completeness… As for rep tempo, take at least a few seconds on the way down and be explosive during concentrism. Congratulations, you should never have to worry about keeping time under pressure again.’

The conclusion

For muscle growth, given the currently available evidence, the following techniques and principles seem to be the best to focus on:

• Work in full range of motion and utilize the stretched position of the reps.
• Perform each of these repetitions lasting two to eight seconds.
• Complete each of these sets lasting 20-70 seconds.
• Use a rep and set range and weight selection that ensures you’re working close to failure at the end of your sets.
• Make sure your programming utilizes progressive overload, which increases the demands on the muscles over time as they adapt.

Kate is a fitness writer for Men’s Health UK where she contributes regular workouts, training tips and nutritional advice. She has a postgraduate diploma in sports performance nutrition and, prior to working at Men’s Health, was a nutritionist, fitness writer and personal trainer with over 5,000 hours of gym coaching under her belt. Kate has a keen interest in volunteering at animal shelters, and when she’s not lifting weights in her garden, she walks her rescue dog.