Time under Tension and Blood Lactate Response during Four Different Resistance Training Methods

Abstract

Mechanical stimuli have often been suggested to be the major determinant of resistance training adaptations; however, some studies suggested that metabolic changes also play an important role in the gains of muscle size and strength. Several resistance training methods (RTM) have been employed with the purpose of manipulating mechanical and metabolic stimuli; however, information about their physiological effects are scarce. The objective of this study was to compare the time under tension (TUT) and blood lactate responses among four different RTM reported in the literature. The four RTM were performed in a knee extension machine at 10 repetition maximum (RM) load by 12 recreationally trained young men. The RTM tested were: 10RM, super-slow (SL-subjects performed one 60-second repetition with 30 seconds for eccentric and 30 seconds for concentric phase), functional isometrics (FI-in each repetition, a five-second maximal isometric contraction was executed with the knees fully extended) and adapted vascular occlusion (VO-subjects performed a 20-second maximal isometric contraction with the knees fully extended and immediately proceeded to normal isoinertial lifts). According to the results, all RTM produced significant increases in blood lactate levels. However, blood lactate responses during FI (4.48Ϯ1.57 mM) and VO (4.23Ϯ1.66 mM) methods were higher than the SL method (3.41Ϯ1.14 mM). The TUT for SL (60 s), FI (56.33Ϯ6.46 s), and VO (53.08Ϯ4.76 s) methods were higher than TUT for 10RM (42.08Ϯ3.18 s). Additionally, TUT for the SL method was higher than TUT during the VO method. Therefore, the SL method may not be recommended if one wants to provide a high metabolic stimulus. The FI method appeared to be especially effective in promoting both type of stimuli.

Determination and comparison of time under tension required to perform 8, 10 and 12-RM loads in the bench press exercise

“…Gentil et al [13] compared four different strength training methods using the same overload in the exercise leg extension. In the method with the traditional protocol of 10-RM, the speed of 2 s for the concentric phase and 2 s for the eccentric, there was a TUT total of 42.08 ± 3.18 s. This differs from the present study that found a much lower TUT.…”

“…These results can be justified because the execution speed was different between studies, which is as fast as possible and held in multi-joint exercise for the upper limbs. Gentil et al [13] also found that the speed of different execution protocols changes the number of repetitions performed, thus interfering directly with the TUT, holding the number of repetitions and the results, as there were found higher lactate levels in a smaller number of repetitions, but a higher TUT was generated compared to the traditional protocol. These results also suggest that the same number of repetitions may generate different TUT for different exercises and muscle groups.…”

“…Thus, there is a need for further studies to examine the muscular responses in the control of strength training variables, in particular, the prescription of exercise intensity from the time under tension [13,15,32]. However, there is still a lack of evidence about the TUT required to perform 8, 10 and 12-RM testing.…”

Training in the functional movement circle to promote strength and mobility-related activities in older adults: a randomized controlled trial

“…All integrated exercises must be defined in aspects of movement velocity, range of motion and trained muscle groups to attain-specific effects. For example, existing resistance training methods (e.g., hypertrophy, inter-muscular coordination, maximum strength) trigger different acute physiologic and metabolic effects (GarciaManso et al 2012;Gentil et al 2006). At the point when the physiological systems have adapted to a given stimulus, higher challenges (difficulty, load intensity, volume) are required to achieve further improvements.…”

Análise eletromiográfica da pré-ativação muscular induzida por exercício monoarticular

“…The 10-MR sets evaluated in experiments of Augustsson et al 5 and Gentil et al 5 represented intensities significantly superior to sets performed at 30% and 60% of 1-MR 25 . This heavy overload induces a larger production of metabolites 18,26 and, therefore, causes a greater activation of muscular receptors sensible to biochemical disturbances, such as the afferent groups III and IV, the muscle spindles and the Golgi tendon organ [27][28][29] . Taking into account that these structures generate a sensorial feedback that reduces the recruitment capacity of the motor units 30 , it is possible that the low amplitude values of the electromyographic signal recorded during the multi-joint exercises analyzed by Augustsson et al 5 and Gentil et al 5 were due to inhibitory mechanisms initiated in the single-joint exercises.…”