Skeletal Muscle Adaptations and Performance Outcomes Following a Step and Exponential Taper in Strength Athletes

Abstract

Before major athletic events, a taper is often prescribed to facilitate recovery and enhance performance. However, it is unknown which taper model is most effective for peaking maximal strength and positively augmenting skeletal muscle. Thus, the purpose of this study was to compare performance outcomes and skeletal muscle adaptations following a step vs. an exponential taper in strength athletes. Sixteen powerlifters (24.0 ± 4.0 years, 174.4 ± 8.2 cm, 89.8 ± 21.4 kg) participated in a 6-week training program aimed at peaking maximal strength on back squat [initial 1-repetition-maximum (1RM): 174.7 ± 33.4 kg], bench press (118.5 ± 29.9 kg), and deadlift (189.9 ± 41.2 kg). Powerlifters were matched based on relative maximal strength, and randomly assigned to either (a) 1-week overreach and 1-week step taper or (b) 1-week overreach and 3-week exponential taper. Athletes were tested pre- and post-training on measures of body composition, jumping performance, isometric squat, and 1RM. Whole muscle size was assessed at the proximal, middle, and distal vastus lateralis using ultrasonography and microbiopsies at the middle vastus lateralis site. Muscle samples (n = 15) were analyzed for fiber size, fiber type [myosin-heavy chain (MHC)-I, -IIA, -IIX, hybrid-I/IIA] using whole muscle immunohistochemistry and single fiber dot blots, gene expression, and microRNA abundance. There were significant main time effects for 1RM squat (p < 0.001), bench press (p < 0.001), and deadlift, (p = 0.024), powerlifting total (p < 0.001), Wilks Score (p < 0.001), squat jump peak-power scaled to body mass (p = 0.001), body mass (p = 0.005), fat mass (p = 0.002), and fat mass index (p = 0.002). There were significant main time effects for medial whole muscle cross-sectional area (mCSA) (p = 0.006) and averaged sites (p < 0.001). There was also a significant interaction for MHC-IIA fiber cross-sectional area (fCSA) (p = 0.014) with post hoc comparisons revealing increases following the step-taper only (p = 0.002). There were significant main time effects for single-fiber MHC-I% (p = 0.015) and MHC-IIA% (p = 0.033), as well as for MyoD (p = 0.002), MyoG (p = 0.037), and miR-499a (p = 0.033). Overall, increases in whole mCSA, fCSA, MHC-IIA fCSA, and MHC transitions appeared to favor the step taper group. An overreach followed by a step taper appears to produce a myocellular environment that enhances skeletal muscle adaptations, whereas an exponential taper may favor neuromuscular performance.

The Tapering Practices of Competitive Weightlifters

“…Travis et al (33) suggested that given the typically high training loads strength athletes employ (generally $85% 1RM) maintaining or decreasing intensity may be a safer option when constructing a taper for maximal strength. In fact, Travis et al (35) recently demonstrated experimentally that during a taper, training intensity can be reduced by 25% and 1RM performances can be improved in powerlifters. It seems that for weightlifting and athletes in the strength sports, the manipulation of training intensity is quite individualized and may be influenced by a number of variables, including the training load and fatigue going into the taper (15,26), the unique physiological demands (2,7,28,42,44) of the sport, and the associated injury epidemiology (13).…”

Analysis of Competition Performance Leading to Success at the International Powerlifting Federation World Championships Between 2013 and 2019

“…Traditionally, PL research has focused on the exploration of anthropometric characteristics (3,7,8), training (1, 19), and tapering practices (4,15,16,18) of PL athletes. However, there have also been several investigations that have used retrospective results from international and national levels of competition to understand competition outcomes (5,(9)(10)(11)(12)(13)20) better.…”

Two Days Versus Four Days of Training Cessation Following a Step-Taper in Powerlifters

“…Tapering has been extensively examined in relation to endurance sports (8,(16)(17)(18)(22)(23)(24)(25)(26)(27)(28)42) with a growing body of evidence relative to strength sports (3,5,12,21,29,31,32,35,36,38,40,44,45). However, the existing literature examining tapering for maximal strength performance consists primarily of observational research (3,5,12,21,32,35,38,44,45).…”