The Best Lifting Tempo and Time Under Tension (TUT)

The tempo of repetition is an essential variable in strength training, which refers to the duration of different phases during a single dynamic repetition. The repetition tempo determines the time of a single repetition. It can be expressed in a four-digit way, such as 1-0-2-0, where each digit represents the duration of a specific repetition phase. The first digit refers to the concentric phase, the second digit to the isometric phase following the concentric phase, the third digit to the eccentric phase, and the fourth digit to the isometric phase following the eccentric phase (Pearson et al., 2021).

The importance of tempo of repetition has been argued with Time Under Tension. TUT is when a muscle is placed under load during a given exercise. This can be determined by multiplying the number of reps performed by the duration of each repetition, including both the concentric and eccentric phases. Research has suggested that TUT is essential in promoting muscle growth, with longer TUT associated with greater hypertrophy. This is because longer TUT may result in more muscle damage and metabolic stress, which can stimulate protein synthesis and promote muscle growth. However, it should be noted that the optimal TUT for hypertrophy may vary depending on various factors, such as exercise selection, intensity, and training status.

There is still a lack of research evidence to draw clear conclusions on the optimal repetition tempo for muscle growth. However, some studies have found that widely varying repetition durations ranging from 0.5-8 seconds can lead to similar muscle growth responses when performed to concentric failure (Schoenfeld et al., 2015). Conversely, hypertrophic responses are worse when a repetition is stretched beyond 10 seconds.

A recent Pearson and colleagues (2021) study investigated the effect of tempo variation in single-joint movement on muscle growth and strength in trained men. The results showed that muscle growth was similar between the fast and slow paces. However, the fast-tempo subjects had slightly better muscle growth in the distal part of the quadriceps (i.e., the straight and middle thigh muscles). Another study also found that tempo variation affects regional hypertrophy of the quadriceps (Diniz et al., 2020).

It has been well established that regular resistance training is an effective means to increase skeletal muscle mass. Findings from previous research suggest that a wide range of movement tempos can be used during resistance training to stimulate muscular hypertrophy. (Wilk et al., 2021) 

For beginners, adjusting the tempo during movement may benefit the most, as a predetermined tempo can increase muscle activity in the target muscle (Headley et al., 2011). For example, it may be justified to perform the concentric steps of repetitions at a tempo of 1-3 seconds and the eccentric steps at a tempo of at least 2 seconds to enhance muscle growth (Schoenfeld, 2021). It is also possible that combining different repetition durations may positively affect muscle growth. Therefore, individuals should work with a qualified trainer to determine the best repetition tempo for their specific needs and goals.

References:

Diniz, R. C., Vechin, F. C., de Oliveira, L. F., & Libardi, C. A. (2020). Tempo of resistance exercise impacts muscle adaptations: a systematic review of longitudinal studies. The European Journal of Applied Physiology, 120(3), 505-517.

Headley, S. A., Henry, K., Nindl, B. C., Thompson, B. A., Kraemer, W. J., & Jones, M. T. (2011). Effects of lifting tempo on one repetition maximum and hormonal responses to a bench press protocol. The Journal of Strength & Conditioning Research, 25(2), 406-413.

Hackett, D. A., Johnson, N. A., & Chow, C. M. (2018). Training practices and ergogenic aids used by male bodybuilders. Journal of Strength and Conditioning Research, 32(6), 1677-1686.

Pearson, S. N., Moore, J. M., Shepherd, S. O., & Hamilton, D. L. (2021). The effect of tempo variation on muscle growth and strength in resistance-trained men. European Journal of Applied Physiology, 121(5), 1495-1507.

Wilk, M., Zajac, A., & Tufano, J. J. (2021). The influence of movement tempo during resistance training on muscular strength and hypertrophy responses: a review. Sports medicine, 51(8), 1629-1650.