Despite playing a pivotal role in building muscle, time under stress and how it affects muscle growth rarely gets the recognition it deserves.
While the likes of high-intensity interval training (HIIT), heavy lifting and protein-rich foods may steal the spotlight, this effective, luxurious training principle has underpinned strength training since the day the first free weight was made. And it is still important in modern home exercises such as using Best adjustable dumbbells (Opens in a new tab).
But what does time under stress mean? In short, it’s the total time your muscles work during the exercise, and this is determined by the number of repetitions you complete in each set as well as the speed at which you complete them.
The difference in time under tension can alter your workout stimulus, helping you target different aspects of fitness such as muscular endurance, Enlargement of the cells (Opens in a new tab) Or muscular strength, says Jinger Gottschall, director of applied research at Wahoo Sports Science (Opens in a new tab).
We spoke to Gottschall at length and examined relevant studies to explore how you can manipulate time under stress to get the most out of your workouts.
Jinger S. Gottschall received her Ph.D. in integrative physiology from the University of Colorado at Boulder and continued her academic career as a Postdoctoral Fellow in Neurophysiology at Emory College of Medicine. She has been an associate professor at Penn State University studying the effectiveness of different exercise regimes for 12 years. For the past 25 years, I have trained running players and endured triathlons from the recreational to the professional level. Most importantly, Ginger has a passion for physical activity and values the paramount importance of promoting balanced, quality training programs.
What time is under stress
Time under tension is simply the amount of time a muscle is stretched during exercise.
This includes both the eccentric and concentric parts of the lift; Lengthening and shortening of working muscles. For example, while the bulk of your effort is used to push the barbell up and away from your chest (the concentric phase), your pectoral muscles will still be under pressure as they control the descent of the bar (the eccentric phase).
Some time manipulations under tension (or rhythm training) may also use isometric contraction. This is where muscle length does not change during contraction – eg, sitting at a wall, where you remain stationary but the muscles in your legs are still under stress.
Does time under stress build muscle?
For anyone who wants to discover How to gain muscle (Opens in a new tab)it is no exaggeration to say that without some time under tension, muscle gain (or Enlargement of the cells (Opens in a new tab)) in adults would be almost impossible.
“Muscle hypertrophy occurs when muscle protein synthesis exceeds muscle protein breakdown and results in a positive net protein balance in cumulative periods,” summarizing a 2019 study published in International Journal of Environmental Research and Public Health (Opens in a new tab). “This can be achieved through resistance training and protein ingestion, which stimulates muscle protein synthesis and leads to a decrease in muscle protein breakdown.”
In other words, you need to do resistance training in some form (like lifting weights or using some of the… The best resistance bands (Opens in a new tab)And eat enough protein if you want to grow muscle. And during this resistance training, your muscles will need to tense for a while.
How does time under stress affect performance?
In gyms around the world, people follow these rough tips:
- Do heavy sets of four to six reps to gain strength.
- Complete 8 to 12 reps at a moderate weight to build muscle.
- Do 12 or more reps at a lighter weight to improve muscular endurance.
Time under tension is the principle behind it. Think:
- If you perform four biceps turns with a 2-second eccentric (down) phase and one second concentric (up) phase, your biceps will be under pressure for 12 seconds.
- If you perform 12 biceps exercises with the same rhythm, then this number increases up to 36 seconds.
Ignore this as a “bro flag” at your own risk though.
“It’s critical to overload the muscles in a way that challenges them toward your goal,” Gottschall says.
But she adds that the cadence and repetition scheme at which you lift (both critical factors in determining your total time under tension) will determine which aspect of fitness your training targets.
“If you want to gain muscular endurance, use lighter weights for more repetitions at a slower speed until voluntary fatigue – in this case, voluntary fatigue is the inability to sustain due to muscular endurance. If you want to gain muscle strength, use heavier weights For fewer repetitions completed more quickly until volitional fatigue.”
So lifting lighter weights for more repetitions to create a longer time under tension can help build muscular endurance, or the ability of a muscle to exert force repeatedly against a prolonged load.
Meanwhile, lifting heavy weights for fewer repetitions to create less time under tension overall can help increase an athlete’s muscular strength — the ability to produce explosive force for a short period of time.
How long under pressure to inflate?
The above two examples focus on lifting light weights at a slower pace to improve muscular endurance or lifting heavy weights at a faster pace to build muscle strength. To gain muscle, a happy medium must be found between these two factors. Gotschall recommends adding weight or repetitions to your regular exercises.
You can also offer cadence training, where you can time the eccentric, isometric and concentric phases of your lifts, to challenge your muscles with new stimuli.
“Spending more time in the eccentric phase of movement increases time under tension,” Gottschall says. “Several studies have reported that training with low loads results in a similar hypertrophy to training with medium and high loads when training to voluntary fatigue.”
However, Gottschall says it is difficult to derive an exact figure for the optimal duration of time under tension for muscle growth from the existing literature.
A 2011 study was published in Journal of Physiology (Opens in a new tab) I found that the leg stretches were completed at a slow pace (six seconds eccentric and center phase) and performed until fatigue produced a greater increase in muscle protein synthesis than the same movement performed quickly. After a 2015 study published in sports medicine (Opens in a new tab) The journal contrasts this, concluding that the muscle hypertrophy observed was similar in a study group when training with different reps lasted anywhere from 0.5 seconds to eight seconds.
So, what type of exercise should you target if inflation is your goal? A 2019 systematic review was published in International Journal of Environmental Research and Public Health (Opens in a new tab) Anyone who wants to increase muscle growth is recommended to perform 3-6 sets of the exercise, each set consisting of 6-12 repetitions. Groups should be divided at 60-second intervals. Put on light weights – you should aim for a moderate intensity of 60 to 80% of your 1RM.
Want to continue to grow? Then increase the training volume by 12-28 sets per muscle, every week.