The concept of increasing time under tension has been around since the beginning of training, but with considerable controversy among the scientific community. The article selected today is:
Self-Selected Vs Fixed Repetition Duration: Effects on Number of Repetitions and Muscle Activation in Resistance-Trained Men.
This article looks at the acute response of increasing TUT compared to a repeat of normal duration and then breaks down previous studies that have investigated long-term outcomes.
- In this study, the ability to perform repetitions in the leg press to be performed with repetitions of normal duration was examined compared to a fixed duration per repetition of 2 ” of eccentric phase (lowering) and 2 ” (concentric).
- The duration for the normal rep was an average of 2.6 ‘per rep as a whole.
- The athletes performed more repetitions (more workload) when they chose the duration of the repetition. Therefore, deliberately slowing the contraction rate acutely compromises performance; therefore, normal eccentric speed and maximum concentric speed are recommended.
It was to examine the differences in repetitions performed, time under tension (TUT), and muscle activation between a self-selected repetition cadence (1-0-1-0, 2.6 ” on average) and a fixed cadence (2- 0-2-0, 4 ”) in men trained through 3 sets to failure at 80% of their RM leg press.
The question at hand is: Does deliberately increasing time under tension per rep affect total volume performed and muscle activation compared to a self-selected rep duration?
Subjects of studies and Methodology
The protocol was contemplated by 12 trained men aged 18-30 years. You can see the details in table 1.
The protocol was simple: 3 sets to failure with 80% in the leg press. The researchers evaluated the repetitions performed, the magnitude of EMG in each set, and the time under tension of each series, repetition and the session as a whole.
Repetitions performed and TUT
In graph 1 average, approximately 60% more repetitions per set were performed in the self-selected condition (25.50 ± 6.10 reps) compared to the fixed condition (15.50 ± 4.42 reps), and 11 of 12 subjects performed more repetitions in the self-selected condition.
The average TUT graphic 2 was 2.6 ” in the self-selected group and increased as the series progressed (in other words, it took more time to complete the repetitions in a state of fatigue), and was close to be different (p = 0.06) for the session as a whole. In the 2: 2 fixed group, the TUT was 4 ” in each repetition.
There was a greater EMG amplitude in the self-selected condition (p <0.05) compared to the 2: 2 fixed condition, probably due to the increased concentric velocity. Both conditions tended to produce greater EMG amplitude during the final portion of the series.
Repetitions performed and TUT
The results clearly show two important points:
On the one hand, we observe how we obtain higher TUT in the 2: 2 fixed cadence condition than in the self-selected 2.6 ” condition.
And on the other hand, by intentionally reducing the execution speed to increase the time under tension, we see how we sacrifice repetitions that we could do, damaging the training volume.
So the main question is: Although the total volume of training is clearly related to hypertrophy (2,3) and strength (4) …
Is there a benefit to sacrificing training volume for more TUT?
In short, we don’t think so, but let’s explore the scientific literature on the cadence of execution of both contraction phases (concentric and eccentric).
Pareja-Blanco et al. (2014) reported that using a maximum intentional concentric speed increased 1RM of the squat significantly more than using half of the above speed for squat training for six weeks (5). That study seems particularly applicable, as it had a fast replay run, which, similar to the Pair-White study, was about half the slowest condition. Another publication by González-Badillo et al. (2014), which appears to be from the same Pair-Blanco data collection, reported the findings of the bench press squat (6). Specifically, for six weeks, the group who bench-pressed three times per week with intentional maximum speed increased their 1RM on the bench press and almost exhibited a rate of increases in strength two times higher (+ 18.2%). compared to those who bench pressed with half their maximum intentional speed (+9.7%) (6). Interestingly, González-Badillo also showed that metabolic stress (blood lactate) was similar between groups after an individual session when sets and repetitions were equalized in the squat study. Even if the repetitions were not matched in the González-Badillo study, we would personally still assume that the metabolic derivatives would be similar, since training at maximum speed would result in more repetitions compared to reduced training speed; thus, more repetitions would compensate for the reduced time under tension.
Verdict for speed of concentric contraction: Aim for maximum intentional speed.
The available evidence on the duration of eccentric contraction indicates similar findings as the evidence for concentric cadence. First, in the previously mentioned studies -upper paragraph-, the duration of eccentric action was not controlled, but it can be deduced that it was slower than in the group that used a slower concentric action; It is necessary to slow down the eccentric action to be able to control the myotatic reflex and actually produce a slower concentric contraction. In terms of intentionally controlled eccentric actions, Paddon-Jones et al. (2001) showed minor hypertrophic and strength adaptations in the biceps over a 10-week period when eccentric speed was deliberately slower (7). Although the results of long-term training studies are the most important, it also appears that recovery from an individual training session is prolonged by eccentric actions (8), which means that deliberately slowing down the eccentric portion It could produce a more abundant fatigue that could require more days of recovery, consequently reducing the frequency and volume of training. In contrast, Chapman et al. (2006) compared the chronology of muscle damage between fast eccentric actions vs. slow, equaled the time under tension, which means that the fast eccentric actions condition performed more repetitions (210) compared to the slow condition (30), resulting in more prolonged muscle damage (9). However, under normal training conditions, when the number of sets is equalized (such as the present study), the time under tension is shorter. Thus, when the number of series is equalized, it is more likely that a stable eccentric duration allows to take advantage of the myotatic reflex and maximize the performance of the concentric portion.
Verdict for the duration of eccentric action: An eccentric speed that allows the technique of execution to be correct to optimize the concentric portion of the movement.
Next steps for researchers
In our opinion, although the idea of increasing the TUT has been established in sports training, it would be interesting to see a study that does NOT equalize the volume per series, but rather that they asked the athletes of the slow speed group to perform additional series for the same the volume of the group that performs quickly. Therefore, research should explore what eccentric duration produces a faster concentric action in search of greater athletic performance.
Application and teaching
An intentionally slower 2: 2 rep duration (2 ’’ eccentric – 2 ’concentric) impairs training volume (performing fewer reps) compared to a fast 1: 1 execution speed)
This study and previous studies clearly show that the concentric action of a movement should be performed with maximum intentional speed to maximize hypertrophy and strength.
Although intentionally increasing TUT over long durations is not the goal during sports training, this does not mean that TUT is unimportant. Rather, an athlete should focus on performing the eccentric action with a controlled cadence, which allows him to maximize the muscle reflex, and thus maximize the performance of the concentric action. This does not mean that eccentric action should not be intentionally slow, but it also means that eccentric uncontrolled could inhibit performance.
- Nóbrega, S. R., Barroso, R., Ugrinowitsch, C., da Costa, J. L. F., Alvarez, I. F., Barcelos, C., & Libardi, C. A. (2018). Self-selected vs. Fixed repetition duration: Effects on number of repetitions and muscle activation in resistance-trained men. The Journal of Strength & Conditioning Research, 32 (9), 2419-2424.
- Schoenfeld, B. J., Ogborn, D., & Krieger, J. W. (2017). Dose-response relationship between weekly resistance training volume and increases in muscle mass: A systematic review and meta-analysis. Journal of sports sciences, 35 (11), 1073-1082.
- Klemp, A., Dolan, C., Quiles, J. M., Blanco, R., Zoeller, R. F., Graves, B. S., & Zourdos, M. C. (2016). Volume-equated high-and low-repetition daily undulating programming strategies produce similar hypertrophy and strength adaptations. Applied Physiology, Nutrition, and Metabolism, 41 (7), 699-705.
- Ralston, G. W., Kilgore, L., Wyatt, F. B., & Baker, J. S. (2017). The effect of weekly set volume on strength gain: a meta-analysis. Sports Medicine, 47 (12), 2585-2601.
- Rodríguez-Rosell, D., Franco-Márquez, F., Pareja-Blanco, F., Mora-Custodio, R., Yáñez-García, J. M., González-Suárez, J. M., & González-Badillo, J. J. (2016). Effects of 6 weeks resistance training combined with plyometric and speed exercises on physical performance of pre-peak-height-velocity soccer players. International journal of sports physiology and performance, 11 (2), 240-246.
- González-Badillo, J. J., Rodríguez-Rosell, D., Sánchez-Medina, L., Gorostiaga, E. M., & Pareja-Blanco, F. (2014). Maximal intended velocity training induces greater gains in bench press performance than deliberately slower half-velocity training. European journal of sport science, 14 (8), 772-781.
- Paddon-Jones, D., Leveritt, M., Lonergan, A., & Abernethy, P. (2001). Adaptation to chronic eccentric exercise in humans: the influence of contraction velocity. European journal of applied physiology, 85 (5), 466-471.
- Paddon-Jones, D., Keech, A., Lonergan, A., & Abernethy, P. (2005). Differential expression of muscle damage in humans following acute fast and slow velocity eccentric exercise. Journal of science and medicine in sport, 8 (3), 255-263.
- Chapman, D., Newton, M., Sacco, P., & Nosaka, K. (2006). Greater muscle damage induced by fast versus slow velocity eccentric exercise. International journal of sports medicine, 27 (08), 591-598.
- Tanimoto, M., Sanada, K., Yamamoto, K., Kawano, H., Gando, Y., Tabata, I., … & Miyachi, M. (2008). Effects of whole-body low-intensity resistance training with slow movement and tonic force generation on muscular size and strength in young men. The Journal of Strength & Conditioning Research, 22 (6), 1926-1938.