Marcelo dos Santos Vaz

Revisiting Tabata's Protocol: Does It Even Exist?

In a recent study, Logan et al. (4) tested the effects of an adaptation of the ‘‘Tabata protocol’’ on the cardiometabolic parameters of low-active male adolescents. The authors stated that the participants performed one to five sets of four repetitions of ‘‘all-out’’ maximum effort exercises lasting 20 s, interspaced with 10 s of passive rest periods. According to the article, participants had the choice of completing the training using different exercises, including cycle ergometers and cross-trainers (a type of elliptical trainer). Although the study yielded interesting results, we would like to make some observations about its methods and practical applications. Twenty years ago, Tabata et al. (8) impressed the scientific community by suggesting that a training protocol lasting 4 min was as, or more, efficient in increasing aerobic power and anaerobic capacity than 1 h of moderately intense activities. Although it is commonly suggested that the original protocol was performed at 170% of V̇O2max (1), the original study used the load necessary to perform seven to nine repetitions of 20 s with a minimum velocity of 85 rpm (8), without reporting any specific intensity. The study that used 170% of V̇O2max used five to six repetitions and was published in 1997 (7). Apparently, both studies were merged to form the recommendations that subsequently become popular. Our laboratories independently tried to replicate the ‘‘Tabata protocol’’ using 170% of the intensity associated with the achievement of maximal oxygen uptake (iV̇O2max) on a cycle ergometer, with most subjects interrupting the exercise by the second or third bout. It appears that using 170% of iV̇O2max is unfeasible, because this intensity is equivalent to running 400 m in 52 s (6). Therefore, it would be unrealistic to propose that it is possible to accumulate 160 s of work at this same rate of intensity by using 20 s:10 s intervals, especially if we consider that cycling elicits a higher peripheral fatigue than running (2). Perhaps due to difficulties in establishing the adequate intensity and consequently replicating the original protocol, there has been an increase in use of the ‘‘Tabata protocols’’ to perform generic forms of ‘‘all-out’’ efforts, as done by Logan et al. (4). Although this has brought interesting results, the physiological responses of these variations do not resemble the original proposition, and they seem to be only feasible in calisthenics, but not replicable on ergometers. When we attempted to use 20 s:10 s with all-out efforts on a cycle ergometer, the participants could barely handle the second bout due to peripheral fatigue and discomfort, even with significant load reduction. In fact, protocols that use 20 s of all-out efforts on cycle ergometers usually use rest intervals of 2 min with only three bouts per session (3). Therefore, given our practical experience and theoretical evidence presented, the inclusion of cycle ergometers in the study of Logan et al. seems to be unrealistic, especially if we consider that the study involved low-active male adolescents. This limitation may also apply to other exercises presented in the study protocol, especially the cross-trainer, because elliptical trainers provide higher stress on the anaerobic metabolism than cycle ergometers (5), which would accentuate peripheral fatigue and discomfort. We think that it is important to address these issues, because other researchers and health professionals may become frustrated when attempting to replicate the study protocol. Moreover, we must use a more critical approach regarding the reproducibility and feasibility of the ‘‘Tabata protocol,’’ and make a special effort to address the undeniable gap that exists between the original protocol and its adaptations.

EFFECTS OF DIFFERENT TRAINING AMPLITUDES ON HEART RATE AND HEART RATE VARIABILITY IN YOUNG ROWERS

Abstract Vaz, MS, Picanço, LM, and Del Vecchio, FB. Effects of different training amplitudes on heart rate and heart rate variability in young rowers. J Strength Cond Res 28(10): 2967–2972, 2014—The aim of this study was to investigate the autonomic nervous system recovery and the psychological response as a result of 3 training amplitudes on heart rate (HR), heart rate variability (HRV), and rate of perceived exertion (RPE) in rowing. Eight young rowers (16.8 ± 1.4 years) performed, in a randomized fashion, 2 sessions of high-intensity interval training, with high and low amplitude and a continuous training (CT) session, with the same exercise duration (10 minutes) and mean intensity (60% of maximal stroke test). The data of HR, HRV, and RPE were collected 5 minutes before, immediately after each session, and 24 hours later. High amplitude promoted higher impact in maximum HR (p ⩽ 0.05) and RPE (p < 0.001) when compared with CT. For the time domain HRV variable, there was a statistically significant difference between moments of rest (pretraining or post 24 hours) and posttraining in all training sessions. Originally, we conclude that training with higher load variation between effort and recovery impacts HRV, HR, and RPE with greater intensity, but the younger rowers were ready for new training sessions 24 hours after either training method. Coaches can use the polarized training method, observing the stimulus nature and time required for recovery, because it may be an adequate strategy for the development of rowers conditioning.