TUT and Rep tempo: slower is not better
Tension is the duration of a muscle's load during a sentence. To increase the size, most believe that you need about 60 to 90 seconds of TUT.
Most lifters pay attention to the repetition rate to increase the TUT. For example, they can make a bicep curl, taking 4 seconds to lower onto the bar (the eccentric) and 2 seconds to raise the bar (the concentric) at each repetition. This is a repeat of 6 seconds. Do 10 reps, and you have 60 seconds in tension.
Changing the playback tempo is one way to increase the time under tension. Simply slowing reps does not necessarily mean that you increase the TUT unless you have a predetermined repeating scheme. So, if you make 1
Let's assume , You DO for 60 seconds. You can do 20 reps at 2: 1 or 10 reps at 4: 2, or any combination of reps and reps that equals 60 seconds. However, if you change the repetition rate while maintaining a similar recurrence scheme, the volume load changes.
Back to the Biceps Curl Example: If you perform a set of 10 reps at the 2: 1 repetition rate and you want failure at the 10th repetition, suppose you can use a 30 pound dumbbell , If you run the same set of 10 at a 4: 2 repetition rate until failure, you may only be able to use a 20-pound dumbbell. So you have increased the TUT at the expense of the loading volume.
This makes the study of TUT so difficult. Intensity (load), load volume, repetition speed, total time under tension and training to failure (or not) are all intertwined. When you adjust one setting, the others also fluctuate.
Researchers have been trying to find the best repetition rate with mixed results. This new study compares two different recurrence tempos and their effects on strength and hypertrophy.
Twenty-four male college football players were recruited for the study. They were split into two counterweight groups. Both groups went through a squat workout twice in a row for six weeks.
They made 3 sets to failure at 75% of their 1RM. The only difference was that one group used an eccentric / concentric 2: 2 tempo and the other a 4: 2. Both groups received 25 g of protein in a shake immediately after training.
The volume load was significantly higher in the 2: 2 group than in the 4: 2 group (36% higher). The 2-2 group made more repetitions in each set before each failure.
Concentric TUT was significantly larger in the 2: 2 group compared to 4: 2 groups (resulting due to the greater number of repetitions). Eccentric or negative TUT were significantly larger in the 4: 2 group than in the 2: 2 group. The total time under tension did not differ significantly between the two groups.
On the performance side, the 1RM of the 2: 2 mid-distance group and at the end of the study was significantly larger than the 4: 2 group. The 1RM increased on average in the 2: 2 group by 17.7 kg compared to the pre-post test. The 1RM value in the 4: 2 group increased on average by 10 kg over the pre-post test.
Now on the results of hypertrophy that you have been waiting for. There was no difference between the groups in the cross-sectional area of the thigh. In both groups significant CSA increases were observed at the proximal, middle and distal thighs. The strongest increases were in the distal area (closest to the knee).
What All These Means
The time under tension has to do with the total SET duration, not with the REP duration.
Equivalent to a total TUT duration over several weeks, the greater benefit still seems to come from the group with a larger load volume. Why? Although CSA growth in this study was similar, force gains between groups were not.
The significantly higher total temporal delay in the 4: 2 group did not result in greater hypertrophy. While slower eccentrics and longer repetitions may be useful in certain situations, the evidence for their superiority in muscle growth and muscle strength is lacking.
With time under tension of the same (equivalent total duration) it seems to be more effective to perform more repetitions at a slightly faster pace.
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- Shibata, K, Takizawa, K, Nosaka, K and Mizuno, M. Effects of extending the eccentric phase duration in parallel back-squat training to a short-term failure on the muscle cross-sectional area, a maximum and repetitive squat Performance tests on football players at universities. J Strength Cond Res XX (X): 000- 000, 2018