Time Under Tension: Effective or a Myth?
TUT is a strength training term that refers to the total amount of time that a muscle or muscle group is under tension. Time Under Tension (TUT) is a term that I have heard discussed since the beginning of my formal coaching experience, especially from the late Charles Poliquin. Charles was a strength coach way ahead of his time, but like the rest of us, he wasn’t right about everything. Before we dive deep into the weeds with TUT, let’s look at what the term means.
- What is Time Under Tension (TUT)
– TUT Training
- Is Time Under Tension a Myth?
- Is TUT Effective?
– TUT for the Concentric Contraction
– TUT for the Eccentric Contraction
– Time Under Tension App
- Hypertrophy and Time Under Tension
- Time Under Tension Workout
– Maximizing Hypertrophy
– Maximizing Strength and Athletic Performance
- Comparing TUT to Other Methods
– Is Time Under Tension better than Reps?
– Time Under Tension or Heavy Weight Training?
– Time Under Tension vs. Explosive Training
– Time Under Tension vs. Failure
What is Time Under Tension (TUT)
Time Under Tension (TUT) is written in a few different ways within the literature, but most coaches will prescribe TUT in the following manner, 4:2:1:1. The 4 refers to the eccentric portion of the lift or the lowering. The 2 refers to a pause in the lengthened position (think about pausing the barbell on one’s chest during the bench press). The first 1 refers to an explosive concentric contraction (muscle shortening), and the second 1 refers to a one second pause at the top of the contraction (the lockout position in a bench press).
Whether you are trying to add muscle or get a bit stronger, there are a few variables that one must consider. Particularly, a coach or athlete needs to track total volume, which consists of a load (the amount of weight on the bar) and total repetitions performed with that load for all the exercises related to a particular muscle group. In my article, Muscle Hypertophy: From Theory to Application, I explained why the main determination of hypertrophy is mechanical tension. In the simplest of terms, the heavier the load that one lifts creates maximum tension. The more repetitions that an athlete can perform with loads that place maximum tension on the muscle will lead to proportionally bigger gains in hypertrophy. The question is, should TUT be a consideration as well?
Proponents for TUT training make their inferences based on the force-velocity relationship that states, for maximal force to occur a slower velocity must be used to allow for maximum myosin-actin crossbridges. Remember, maximum mechanical tension is created by a slower repetition velocity. However, is mechanical tension maximized by artificially slowing down the tempo of a repetition with a submaximal load? You can look deeper into repetition velocity here: Repetition Velocity: The Adaptation is in the Speed.
The problem is another scientific principle, The Size Principle. This principle states that motor units are recruited in order of size. That means low threshold motor units(LTMUs) are recruited to perform submaximal loads, and high threshold motor units(HTMUs) are recruited to overcome maximum loads with maximum effort. Therefore, submaximal loads performed at slower tempos aren’t going to recruit HTMUs until the load being used becomes maximal requiring a maximum effort and a slow tempo that is maximal.
Maximum hypertrophy and maximum force production of skeletal muscle requires:
- Maximum effort recruiting the high threshold motor units, which can be defined as the maximum possible velocity for a given load.
- A slow velocity to enable a maximum number of cross bridges, so experiencing near failure in a given set of repetitions maximizing effort.
There’s no way around it. Without performing repetitions with a maximum velocity and effort that naturally leads to slower repetition velocities, hypertrophy and strength won’t be optimized. However, TUT is a way of creating fatigue with submaximal loads with a less requirement of repetitions as long as the athlete performs the repetitions to near failure resulting in a tempo that is naturally lower versus artificially controlled.
Is Time Under Tension a Myth?
TUT isn’t a myth at all. It simply might not be effective in the way that it has been used by bodybuilders in the past. It’s still important to be aware of the eccentric contraction rate, the isometric rates, and the concentric rates. There’s even a case for implementing TUT or tempo training for athletes just getting started to develop coordination before jumping into maximum velocities. The 1×20 Strength Training Program is a great way for athletes to learn functional movement patterns, which is an indirect way of increasing the athlete’s TUT by increasing the number of repetitions. The neuromuscular system needs to understand the movement pattern before it can efficiently perform at a high rate.
It’s also important to understand an athlete’s current concentric and eccentric rates to monitor improvement. If an athlete performs a 182kg/400lb back squat, it’s important to monitor the rate of the concentric contraction for signs of improvement. If the concentric contraction takes 3 seconds to complete and in a few weeks it only takes 2 seconds to perform the same load, the athlete has improved their rate of recruiting motor units. The same can be said for the eccentric contraction. If an athlete lowers the same 182kg/400lb in 3 seconds and in a few weeks can control it for 4 seconds, their eccentric force production has improved.
If you think about it, velocity is a look at time under tension. Velocity is simply distance/time which is another way of looking at the rate/time. Both GymAware RS and FLEX units measure both the concentric and eccentric velocities and rates, so GymAware has you covered on TUT. Whether TUT is effective or not, like anything else, is all in how you use it.
Is TUT Effective?
This question is answered with an affirmative or negative depending upon the application. Is time under tension important? That’s another question that depends on the application. Below we are going to explain a few ways that TUT is effective and important. It might not be the way that people have framed TUT as important in the past, but nevertheless, the time an athlete keeps his or her muscles under tension is very important. Let’s start with some ways that TUT might be effective and important.
TUT for the Concentric Contraction
Besides the passive forces that are generated from the stretch shortening cycle (SSC) and elasticity during the amortization phase that occurs at the end of the eccentric contraction, the concentric contraction rates are determined by that athlete’s ability to recruit high threshold motor units, the rate of that recruitment, and the synchronization /coordination of the recruitment. All of these adaptations are important for athletic performance. If you think about a vertical leap or broad jump, the importance becomes clear. Therefore, instead of purposely moving at a slow rate (the typical way TUT is used), try to decrease the time under tension to stimulate adaptations leading to improved performance. The adaptation truly is in the speed of the contraction.
TUT for the Eccentric Contraction
Here’s where it gets fun for me, and hopefully you will agree. Yes, TUT is important and effective especially if you are considering accentuated eccentric loading (AEL). At the Australian Strength and Conditioning Association conference, I was able to hear a presentation from Dr. Tim Suchomel on this very topic. Here are some quick pointers for maximizing the gains from AEL:
- Measure an athlete’s typical eccentric contraction rate with heavy loads along with their concentric contraction rate with 70-80%
- Eccentric phase with a supramaximal 110%-120% of the athlete’s 1RM paired with 70-80% during the concentric phase
- Of course weight releasers were used
- Eccentric rates at or faster than normal rates along with supramaximal loads are required for maximum strength, RFD, SSC efficiency, hypertrophy, power output, muscle fiber, and architectual adaptations.
- The key is monitoring the concentric and eccentric rates and/or velocities.
In summary, the first step is to measure the individual athlete’s typical eccentric contraction rate. Then to maximize the adaptations from AEL, use supramaximal loads for the eccentric portion between 110-120%, and monitor the eccentric rate to ensure that the athlete is moving at their typical rate or slightly faster 1-2 seconds at most. You must also measure their concentric contraction to ensure the concentric rates are increasing for rate coding enhancements.
Time Under Tension App
If you are reading this and thinking that there is no way that you plan on standing by each of your athletes with a stopwatch, I want you to take a deep breath and know that I have a solution. Whether you are using the GymAware RS APP on an IPAD or you are grinding in your garage with the GymAware FLEX APP on your IPhone, your total TUT, eccentric rate, and of course the eccentric and concentric velocities are measured, recorded, and stored for you automatically.
Hypertrophy and Time Under Tension
The problem with TUT principles of the past where an athlete picks an arbitrary tempo of say 6-seconds for the eccentric phase, 2 seconds paused in the bottom, and a 4-second concentric rate with a weight that is submaximal to accommodate for the longer TUT is the size principle states that HTMUs aren’t recruited until there’s a resistance high enough to require the bigger motor units. Mechanical tension is the primary mechanism required for muscle hypertrophy. Maximum hypertrophy requires the following:
- Maximum effort into the bar or machine
- Maximum velocity for the given load
- Getting as close to failure as possible to require maximum HTMUs (Size Principle)
- Barbell must slow down due this near failure effort allowing for maximum myosin and actin crossbridges (Force-Velocity relationship)
Artificially lowering the rate of repetition won’t allow for an effort requiring HTMUs. However, if an athlete continues with enough of these artificially slower repetitions until enough fatigue is reached rendering the repetition rate near maximal, then the above four principles are met triggering hypertrophy. However, based on a recent meta-analysis by Schoenfeld et al. , longer TUT failed to render more hypertrophy than traditional training. Therefore, based on the work of Suchomel et al. , if you want to maximize strength and athletic performance, long duration TUT might not be the solution.
Instead of thinking about artificially increasing an athlete’s TUT for muscle hypertrophy, the better solution is to monitor eccentric and concentric velocities and/or rates to ensure maximum effort and velocity are being achieved. Another way to monitor TUT in a way that will render maximum hypertrophy is to monitor velocity loss or to ensure that the rates of contraction are slowing due to an increase in fatigue. All of these parameters are measured for you on the GymAware iPad and FLEX Stronger Apps. If getting jacked is your primary concern, I recommend that you take a look at my Hypertrophy Article where I break it down completely and give you suggestions for maximizing your gains.
Time Under Tension Workout
Whether you are trying to gain muscle, get stronger, or increase athletic performance, I recommend starting with measuring your typical eccentric and concentric contraction rates at various loads. Once again, velocity (distance/time) is already looking at these variables if you own a GymAware RS or FLEX unit. Once you have these variables, here are some suggestions.
For loads above 80%, each and every repetition requires an effort and repetition velocity that will stimulate hypertrophy. The key will be to maximize the number of total repetitions per body part to optimize hypertrophy. It appears that ten sets per body part is optimal for maximum hypertrophy. If you choose to use lighter loads, a tempo similar to your typical repetition tempo at 80%+ is still required to maximize hypertrophy. I will add that an artificial rate caused from a preset tempo rate won’t create the mechanical tension necessary to stimulate maximum hypertrophy.
A simpler way of looking at this is with velocity. A typical velocity for the back squat for someone at an ~height of 5’9” with a load of 80% is 0.5m/s. Therefore, if you start with 60% at 0.85m/s, you will need to rep out until you are at or below 0.5m/s for as many repetitions as possible. If you read Chris Beardsley’s work, you will find that there are about 5 hypertrophy stimulating repetitions per set. If you follow all the recommendations or 10 sets per body part with a maximum of 5 hypertrophy stimulating repetitions, then you will need to perform enough sets regardless of load that equate to a total of 50 repetitions per body part.
Therefore, whether you want to perform low loads with high repetitions or heavy loads at fewer repetitions, you are still working towards the same goal. One suggestion I have is that you monitor total velocity loss. Some bodybuilders will work to a velocity loss of 40-60%, which is basically failure or really close. You can gain almost as much hypertrophy at 25% velocity loss without a lot of the negative adaptations that come with extreme velocity loss. Plus, 25% is easier to recover from making frequency a bit more attainable. If you don’t have a GymAware Unit, you can still manage this with a stopwatch, but of course the accuracy will be hit or miss and depending on the number of athletes, this could be a lot of work.
Maximizing Strength and Athletic Performance
After reading Dr. Suchomel’s work on AEL, I would invest in some weight releasers which aren’t expensive. I would measure the athlete’s typical eccentric and concentric contractions, and then I would implement AEL. I would add between 105-120% with weight releasers making the optimal load whatever slightly increased the rate of the athlete’s eccentric contraction by an ~1 second paired with 70-80% for repetitions between 3-5. Yes, only the first repetition will have the accentuated eccentric load, but Dr. Suchomel’s research has shown that the following reps are enhanced as well from potentiation. The key is to also ensure that the concentric rates are enhanced as well for maximum athletic adaptations especially in the first 2-3 reps.
Based on Dr. Suchomel’s findings, I would not worry so much about an arbitrary tempo, but instead, base the prescriptions on the individual’s repetition rate. Otherwise, if an athlete sways too far from their normal mechanics, the neuromuscular coordination and synchronization is compromised too greatly. If this sounds too time consuming, remember that both the GymAware RS and FLEX Units have an App that will do it for you. The FLEX Stronger App will store this information for the individual, and the GymAware Cloud stores this information for an entire team or teams.
Comparing TUT to Other Methods
Let’s take a look at TUT as compared to a few other popular methods:
Is Time Under Tension better than Reps?
By now we have shown that TUT in the traditional sense isn’t any better than traditional repetitions to near failure. Regardless if you are using a tempo or simply busting out reps of a particular load, you are required to use maximum effort, maximum velocity, reach near failure, and use a max effort repetition speed that slowed down due to fatigue. These four requirements will maximize HTMU recruitment along with myosin-actin crossbridges. Therefore, if you use a tempo that artificially creates a longer TUT, you must stick with that tempo until the repetition rate isn’t artificial but instead maximal. The total volume will need to be somewhere around 10 sets of 5 hypertrophy stimulating repetitions per body part.
Time Under Tension or Heavy Weight Training?
This depends on the goal of course. If your goal is to get jacked, TUT taken to near failure will equal a similar gain in hypertrophy as long as the volume of hypertrophy stimulating repetitions is equal. However, if your goal is strength and athletic performance, heavy weight is going to maximize strength, power, SSC efficiency, and neuromuscular synchronization. If strength and athletic performance was my goal, I would take a look at Dr. Suchomel’s work on AEL pairing supramaximal eccentric loads with submaximal concentric loads (105-120% eccentric paired with 70-80% concentric).
Time Under Tension vs. Explosive Training
Once again, if strength and athletic performance is the goal, maximum velocity in each contraction is the goal for recruiting HTMUs at the highest possible rate. If I am trying to look good on the beach, a slower tempo with TUT training will do the trick. Of course, it will require enough repetitions for the tempo to become maximal in effort.
Time Under Tension vs. Failure
TUT evolved from the bodybuilding community to maximize hypertrophy with submaximal loads. TUT and tempo are synonymous with each other as TUT is in reference to a slower overall tempo. Regardless, a slower tempo not taken to at least near failure is probably wasting time. A slow tempo not taken to near failure isn’t gaining any athletic performance or strength adaptations. Since hypertrophy requires a maximum effort and velocity along with a slower repetition velocity due to fatigue, TUT not taken to near failure isn’t going to create much of an adaptation at all.
Even though the method of time under tension that was created in the bodybuilding world probably doesn’t render the maximum hypertrophy that the creators thought, there is still a place for looking at TUT. A better use of TUT is taking a look at an individual’s typical eccentric and concentric rates, and then using other methods like AEL or accommodating resistance to improve those rates or the loads that are handled at those rates. Tempo is important, but artificially lowering an athlete’s tempo isn’t optimal for gaining muscle mass, strength, or athletic performance traits. I hope this article opened your eyes to a whole new way of looking at TUT.
Coach Travis Mash, MSc
P.S. As always, email me at Travis@GymAware.com with any questions or suggestions for future topics.
- Douglas J, Pearson S, Ross A, McGuigan M. Chronic Adaptations to Eccentric Training: A Systematic Review. Sports Med. 2017 May;47(5):917-941. doi: 10.1007/s40279-016-0628-4. PMID: 27647157.
- Suchomel TJ, Wagle JP, Douglas J, Taber CB, Harden M, Haff GG, Stone MH. Implementing Eccentric Resistance Training—Part 1: A Brief Review of Existing Methods. Journal of Functional Morphology and Kinesiology. 2019; 4(2):38. https://doi.org/10.3390/jfmk4020038
- Suchomel TJ, Wagle JP, Douglas J, Taber CB, Harden M, Haff GG, Stone MH. Implementing Eccentric Resistance Training—Part 2: Practical Recommendations. Journal of Functional Morphology and Kinesiology. 2019; 4(3):55. https://doi.org/10.3390/jfmk4030055
- Schoenfeld BJ, Ogborn DI, Krieger JW. Effect of repetition duration during resistance training on muscle hypertrophy: a systematic review and meta-analysis. Sports Med. 2015 Apr;45(4):577-85. doi: 10.1007/s40279-015-0304-0. PMID: 25601394.
Being a World Champion in powerlifting, Travis competed at a world-class level in Olympic weightlifting and has coached professional Olympic weightlifters alongside Don McCauley and Glenn Pendlay at Team MDUSA. Now Travis coaches the most successful weightlifting team in the USA.