This study used transcranial magnetic stimulation to measure the corticospinal responses following 8 weeks of unilateral leg strength training. Eighteen healthy, non-strength trained participants (14 male, 4 female; 18-35 years of age) were matched for age, gender, and pre-training strength; and assigned to a training or control group. The trained group participated in unilateral horizontal leg press strength training, progressively overloaded and wave periodised, thrice per week for 8 weeks. Testing occurred prior to the intervention, at the end of 4 weeks and at the completion of training at 8 weeks. Participants were tested in both legs for one repetition maximum strength, muscle thickness, maximal electromyography (EMG) activity, and corticospinal excitability and inhibition. No changes were observed in muscle thickness in either leg. The trained leg showed an increase in strength of 21.2% (P = 0.001) and 29.0% (P = 0.007, compared to pre-testing) whilst the untrained contralateral leg showed 17.4% (P = 0.01) and 20.4% (P = 0.004, compared to pre-testing) increases in strength at 4 and 8 weeks, respectively. EMG and corticospinal excitability did not change; however, corticospinal inhibition was significantly reduced by 17.7 ms (P = 0.003) and 17.3 ms (P = 0.001) at 4 and 8 weeks, respectively, in the trained leg, and 25.1 ms (P = 0.001) and 20.8 ms (P = 0.001) at 4 and 8 weeks, respectively, in the contralateral untrained leg. This data support the theory of corticospinal adaptations underpinning cross-education gains in the lower limbs following unilateral strength training.

BackgroundCluster sets (CSs) are a popular resistance training (RT) strategy categorised by short rest periods implemented between single or groups of repetitions. However, evidence supporting the effectiveness of CSs on acute intra-session neuromuscular performance is still equivocal.ObjectiveThe objective of this investigation was to determine the efficacy of a single session of CSs to attenuate losses in force, velocity and power compared to traditional set (TS) training.MethodsScreening consisted of a systematic search of EMBASE, Google Scholar, PubMed, Scopus and SPORTDiscus. Inclusion criteria were (1) measured one or more of mean/peak force, velocity or power; (2) implemented CSs in comparison to TSs; (3) an acute design, or part thereof; and (4) published in an English-language, peer-reviewed journal. Raw data (mean ± standard deviation) were extracted from included studies and converted into standardised mean differences (SMDs) and ± 95% confidence intervals (CIs).ResultsTwenty-five studies were used to calculate SMD ± 95% CI. Peak (SMD = 0.815, 95% CI 0.105–1.524, p = 0.024) and mean (SMD = 0.863, 95% CI 0.319–1.406, p = 0.002) velocity, peak (SMD = 0.356, 95% CI 0.057–0.655, p = 0.019) and mean (SMD = 0.692, 95% CI 0.395–0.990, p < 0.001) power, and peak force (SMD = 0.306, 95% CI − 0.028 to 0.584, p = 0.031) favoured CS. Subgroup analyses demonstrated an overall effect for CS across loads (SMD = 0.702, 95% CI 0.548–0.856, p < 0.001), included exercises (SMD = 0.664, 95% CI 0.413–0.916, p < 0.001), experience levels (SMD = 0.790, 95% CI 0.500–1.080, p < 0.001) and CS structures (SMD = 0.731, 95% CI 0.567–0.894, p < 0.001) with no difference within subgroups.ConclusionCSs are a useful strategy to attenuate the loss in velocity, power and peak force during RT and should be used to maintain neuromuscular performance, especially when kinetic outcomes are emphasised. However, it remains unclear if the benefits translate to improved performance across all RT exercises, between sexes and across the lifespan.Electronic supplementary materialThe online version of this article (10.1007/s40279-019-01172-z) contains supplementary material, which is available to authorized users.

Our results suggest that: (1) the acute behaviour of neurophysiological measures is similar between HST and HYT; and (2) the increase in corticospinal excitability may be a compensatory response to attenuate peripheral fatigue.

Latella, C, Teo, W-P, Spathis, J, and van den Hoek, D. Long-term strength adaptation: A 15-year analysis of powerlifting athletes. J Strength Cond Res 34(9): 2412–2418, 2020—Strength is a fundamental component of athletic performance and development. This investigation examined the long-term strength development of powerlifting (PL) athletes. The rate of strength gain/day was assessed in 1897 PL athletes (F = 626, M = 1,271) over a 15-year period (2003–2018). Independent T-tests explored sex differences in baseline absolute (kg) and relative strength (kg·body mass −1 [bm]) recorded from the first competition, and strength gain/day (kg·d −1 ). Analyses based on initial strength quartiles were conducted using one-way analysis of variances with significance set at p < 0.05. Bivariate correlational analysis tested for relationships between strength gain/day and baseline strength, the number of competitions, and mean days between competitions. Males had greater absolute (M: 513.3 ± 99.8 kg, F: 289.4 ± 55.7 kg, p < 0.001) and relative (M: 5.89 ± 1.04 kg·bm −1 , F: 4.27 ± 0.85 kg·bm −1 , p < 0.001) strength at baseline. Overall, strength gain/day (F: 0.12 ± 0.69 kg·d −1 , M: 0.15 ± 0.44 kg·d −1 , p = 0.318) was similar between sexes. However, the strongest males showed a lower rate of strength improvement (0.102 kg·d −1 ) compared with least strong males (0.211 kg·d −1 ), p = 0.010. No differences were observed across quartiles for females. Correlational analyses revealed significant but weak negative relationships between strength gain/day and the mean days between competitions for females ( r 2 = −0.120, p = 0.003) and males ( r 2 = −0.190, p < 0.001). Similar relationships were observed for baseline strength ( r 2 = −0.073, p = 0.009) and the number of competitions ( r 2 = −0.111, p < 0.001) for males. The results suggest similar strength adaptation between sexes. The strongest males improve more slowly, possibly due to a ceiling effect. Collectively, the findings provide novel evidence of real-world long-term strength adaptations that may be particularly useful to understand athlete development, to aid periodized programming, and to benchmark strength over time.

The ongoing global pandemic brought about by Coronavirus II (SARS-Cov-2 or COVID-19) has caused an ongoing cessation of sporting competitions and training facility closures. This is a fundamental challenge for amateur and elite sporting professionals. Although recommendations have been provided for team-sport athletes to maintain general and sport-specific conditioning, these methods are often not optimal for strength athletes (i.e., powerlifting (PL) and weightlifting (WL)) due to the unique and narrow set of performance requirements posed by these sports. The purpose of this review is to provide evidence-based information and recommendations and highlight potential strategies and approaches that may be used by strength (PL and WL) athletes during the current global crisis. Collectively, we provide evidence from resistance training literature regarding the loss of muscle strength, power and mass, minimum training frequencies required to attenuate such losses and training re-adaptation. Additionally, we suggest that time off training and competition caused by ongoing restrictions may be used for other purposes, such as overcoming injury and improving movement quality and/or mobility, goal setting, psychological development and emphasizing strength sports for health. These suggestions are intended to be useful for coaches, strength athletes and organizations where existing training strategies and recommendations are not suitable or no longer feasible.

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Powerlifting (PL) is characterised by the ability to generate maximal force. However, an understanding of the factors affecting strength in PL athletes is poorly understood. Therefore, competition data was analysed from 1368 individuals during 2017. Relative strength was compared for the squat (SQ), bench press (BP) and deadlift (DL) between age groups (subjunior [SJ], junior [JU], open [OP], and masters' I-IV [M1-M4]), weight classes (females; 47kg, 52kg, 57kg, 63kg, 72kg, 84kg and +84kg and males; 59kg, 66kg, 74kg, 83kg, 93kg, 105kg, 120kg, +120kg) and between sexes. The results showed that relative strength was greater for males across all lifts (P < 0.001). Relative strength tended to decrease with increasing body mass for males; (SQ, BP and DL: P<0.001, R 2 = 0.9306-0.9763) and females; (SQ, BP and DL: P<0.001, R 2 = 0.9485-0.9802), and with increasing age for males

Objective: The current understanding of acute neurophysiological responses to resistance training remains unclear. Therefore, we aimed to compare the time-course of acute corticospinal responses following a single-session heavy strength training (HST) of the biceps brachii (BB) muscle and provide quantifiable evidence based on the super-compensation model in an applied setting.Methods: Fourteen participants completed a counter-balanced, cross-over study that consisted of a single HST session (5 sets × 3 repetition maximum [RM]) of the BB and a control session (CON). Single- and paired-pulse transcranial magnetic stimulation (TMS) was used to measure changes in motor-evoked potential (MEP) amplitude, intra-cortical facilitation (ICF), short-interval intra-cortical inhibition (SICI) and long-interval intra-cortical inhibition (LICI). Additionally, maximal muscle compound wave (MMAX) and maximal voluntary isometric contraction (MVIC) of the BB were taken. All measures were taken at baseline, immediately post and at 10, 20, 30 min and 1, 2, 6, 24, 48 and 72 h post-training.Results: A significant reduction in MEP amplitude was observed immediately post training (P = 0.001), while MVIC (P < 0.001) and MMAX (P = 0.047) were reduced for up to 30 min post-training. An increase in MVIC (p < 0.001) and MMAX (p = 0.047) was observed at 6 h, while an increase in MEP amplitude (p = 0.014) was only observed at 48 and 72 h. No changes in SICI, ICF and LICI were observed.Conclusion: Our results suggest that: (1) acute changes in corticospinal measures returned to baseline in a shorter timeframe than the current super-compensation model (24–48 h) and (2) changes in corticospinal excitability post-HST may be modulated “downstream” of the primary motor cortex (M1).