High-intensity cycling training:the effect of work-to-rest intervals on running performance measures

The work-to-rest ratio during cycling-based high-intensity interval training (HIT) could be important in regulating physiological and performance adaptations. We sought to determine the effectiveness of cycling-based HIT with different work-to-rest ratios for long-distance running. Thirty-two long-distance runners (age: 39 ± 8 years; sex: 14 men, 18 women; average weekly running training volume: 25 miles) underwent baseline testing (3-km time-trial, V[Combining Dot Above]O2peak and time to exhaustion, and Wingate test) before a 2-week matched-work cycling HIT of 6 × 10-second sprints with different rest periods (30 seconds [R30], 80 seconds [R80], 120 seconds [R120], or control). Three-kilometer time trial was significantly improved in the R30 group only (3.1 ± 4.0%, p = 0.04), whereas time to exhaustion was significantly increased in the 2 groups with a lower work-to-rest ratio (R30 group 6.4 ± 6.3%, p = 0.003 vs. R80 group 4.4 ± 2.7%, p = 0.03 vs. R120 group 1.9 ± 5.0%, p = 0.2). However, improvements in average power production were significantly greater with a higher work-to-rest ratio (R30 group 0.3 ± 4.1%, p = 0.8 vs. R80 group 4.6 ± 4.2%, p = 0.03 vs. R120 group 5.3 ± 5.9%, p = 0.02), whereas peak power significantly increased only in the R80 group (8.5 ± 8.2%, p = 0.04) but not in the R30 group (4.3 ± 6.1%, p = 0.3) or in the R120 group (7.1 ± 7.9%, p = 0.09). Therefore, cycling-based HIT is an effective way to improve running performance, and the type and magnitude of adaptation is dependent on the work-to-rest ratio

Concurrent training

Many sports require a range of physical qualities including strength, power and aerobic capacity for optimal performance. Subsequently, training is likely to contain periods where concurrent development of fitness components is required and will typically be classified into two training categories, endurance and strength training. In order to optimize training, the interaction of these fitness components should be considered as endurance training may interfere with resistance training sessions via conflicting molecular signaling which may blunt optimal muscular development. At present, there is a range of conflicting recommendations in the literature due to the challenges of comparing different training studies and the variables which impact upon the magnitude of adaptation; including volume, intensity, sequencing, rest and concurrent training goals. Most importantly, the overall training stress should be considered to limit cumulative fatigue and minimize the potential negative effect on strength adaptations via dampened hypertrophic responses. Inter-session rest should be maximized wherever possible to reduce the interaction between competing molecular signaling pathways. Where required, strength training should be completed after aerobic endurance training to ensure overnight recovery facilitates strength based adaptations. Overall, optimal planning during concurrent training is a complex interaction between a range of variables where strength and conditioning professionals should be conscious of a range of factors and select a training regime that minimized the interference effect but also fits with their own training logistics

The effects of complex training on neuromuscular development of the lower limbs in youth netball players

Objective: The high prevalence of injury in netball can be associated with intrinsic or extrinsic factors. Female athletes have an increased risk of injury as they enter into maturity due to increased joint laxity and a reduction in neuromuscular control, resulting in altered landing biomechanics and greater knee joint injury risk. This study sought to investigate whether complex training (CT) could improve neuromuscular strength and landing kinematics, thereby reducing injury risk to the knee. Methods: A within subject, repeated measures design was utilised. Ten youth netball academy players (age, 15.3 ± 0.9, years; height, 169.0 ± 7.0, cm; body mass, 62.2 ± 6.9, kg) participated and attended one familiarisation and two testing sessions (pre- and post-intervention). Participants’ were assessed on: countermovement jump (CMJ), landing error score system (LESS), and single leg countermovement jump (SLCMJ) of both limbs. All participants engaged in a 6 week, one day per week, strength training and plyometric intervention for the lower limbs utilising CT. Results: Significant improvements were evidenced for CMJ height (p = 0.001, d = 1.2 “moderate” effect), CMJ peak power output (PPO) (p = 0.001, d = 0.7 “small” effect), LESS (p = 0.002, d = 1.7 “large” effect), and SLCMJ left height (p = 0.01, d = 1.2 “moderate” effect) following the intervention. Conclusion: Performing one CT session a week over 6 weeks enhanced kinematics and performance of jumping activities both bilaterally and unilaterally, it also brought about reductions in asymmetries in young female athletes

Autoregulation in resistance training : addressing the inconsistencies

Autoregulation is a process that is used to manipulate training based primarily on the measurement of an individual's performance or their perceived capability to perform. Despite being established as a training framework since the 1940s, there has been limited systematic research investigating its broad utility. Instead, researchers have focused on disparate practices that can be considered specific examples of the broader autoregulation training framework. A primary limitation of previous research includes inconsistent use of key terminology (e.g., adaptation, readiness, fatigue, and response) and associated ambiguity of how to implement different autoregulation strategies. Crucially, this ambiguity in terminology and failure to provide a holistic overview of autoregulation limits the synthesis of existing research findings and their dissemination to practitioners working in both performance and health contexts. Therefore, the purpose of the current review was threefold: first, we provide a broad overview of various autoregulation strategies and their development in both research and practice whilst highlighting the inconsistencies in definitions and terminology that currently exist. Second, we present an overarching conceptual framework that can be used to generate operational definitions and contextualise autoregulation within broader training theory. Finally, we show how previous definitions of autoregulation fit within the proposed framework and provide specific examples of how common practices may be viewed, highlighting their individual subtleties

Electromyographic and Kinetic Comparison of the Back Squat and Overhead Squat

The purpose of this study was to compare muscle activity and kinetics during the back squat and overhead squat performed at 3 relative intensities (60, 75, and 90% 3 repetition maximum). Fourteen subjects (age, 26 ± 7 years; height, 182.5 ± 13.5 cm; body mass, 90.5 ± 17.5 kg) performed each exercise using a within-subjects crossover design. In addition, a selection of trunk isolation exercises were included to provide additional comparisons. Squats were performed on a force platform with electromyographic activity of the anterior deltoid, rectus abdominis (RA), external oblique (EO), erector spinae (ES), gluteus maximus, vastus lateralis, biceps femoris, and lateral gastrocnemius recorded throughout. The overhead squat demonstrated significantly greater (p ≤ 0.05) activity in the anterior trunk muscles (RA and EO) during the eccentric phase. However, the magnitudes of the differences were relatively small (approximately 2–7%). In contrast, the back squat displayed significantly greater (p ≤ 0.05) activity in the posterior aspect of the trunk ES and all lower-body muscles during the concentric phase. Kinetic comparisons revealed that significantly greater peak force (p ≤ 0.05) was developed during the back squat. Electromyographic comparisons between the trunk isolation exercises and squat variations demonstrated substantially greater anterior trunk activity during the isolation exercises, whereas the highest activity in the posterior aspect of the trunk was obtained during the squats (p ≤ 0.05). The results of the study do not support the hypothesis that the overhead squat provides a substantially greater stimulus for developing the trunk musculature compared with the back squat

Concurrent Training

For optimal sports performance, many athletes will require a range of physical qualities including strength, power, and aerobic capacity. Subsequently, training is likely to contain periods where concurrent development of fitness components is required and can typically be classified into two simple training paradigms, endurance and strength training. In order to optimise training, the interaction of these fitness components should be considered as endurance training may interfere with strength training sessions via conflicting molecular signaling which may blunt optimal muscular development. At present, there are a range of conflicting recommendations in the literature, due to the challenges of comparing different training studies and the variables which impact upon the magnitude of adaptation; including volume, intensity (load), rest, sequencing, and concurrent training goals. Most importantly, the overall training stress should be considered to reduce cumulative fatigue and minimise the potential negative effect on strength adaptations via dampened hypertrophic responses. Inter-session rest should be maximized wherever possible to reduce the interaction between competing molecular signaling pathways and provide opportunity to refuel as excesive bouts of training when fuel depleted may restrict subsequent training intensities and blunt any potential adapatations. When training sessions must be completed in close proximity, sequencing should consider the desired training adaptations. If strength adaptations are priority, training sessions should be sequenced, strength-endurance to maximise the strength stimulus. Overall, optimal planning during concurrent training is a complex interaction between a range of variables where strength and conditioning professionals should be conscious of a series of factors and select a training regime that minimises the interference effect within the constraints of their own training logistics

The effects of strength and conditioning interventions on sprinting performance in team sport athletes: a systematic review and meta-analysis.

Linear sprinting is a key determinant of athletic performance within team sports. The aims of the review were to quantify and compare the effectiveness of popular strength and conditioning (S&C) training modes to improve sprint performance in team sport athletes, with additional focus on potential moderators and the relationships between improvements in physical factors (e.g. strength, power and jump performance) and improvements in sprint performance. Inclusion was restricted to resistance, plyometric, sprint and combined training interventions comprising team sport athletes. Multi-level, Bayesian meta-analysis and meta-regression models conducted with standardised mean difference effect sizes were used to investigate training modes and potential moderators. Weighted regression models conducted on shrunken estimates from initial Bayesian meta-analyses were used to quantify relationships between improvements in physical factors and improvements in sprint performance. Certainty of evidence was assessed using the Grading of Recommendations Assessment Development and Evaluation (GRADE) approach. Similar improvements in sprint performance were obtained across training modes, with some evidence of the largest effects with resistance training (SMD_(Pre_0.5 )=0.55 [95%CrI:0.36-0.78; very low certainty]). A strong moderating effect of training intensity was identified across all training modes with evidence of greater improvements in sprint performance with high intensity training (β_(Low:High_0.5 )=0.17 [95%CrI:0.01-0.33; very low certainty]). Strong positive relationships were identified between improvements in all physical factors and sprint performance (β_Strength_0.5=0.56 [95%CrI:0.36-0.77; low certainty], β_Power_0.5=0.80 [95%CrI:0.50-1.0; low certainty], β_Jump_0.5=0.78 [95%CrI:0.57-0.97; low certainty]). The findings indicate that focus on developing speed in team sport athletes should be placed on S&C training with high intensities, including the use of resisted sprint training

The predictive validity of individualised load-velocity relationships for predicting 1RM: a systematic review and individual participant data meta-analysis.

Load-velocity relationships are commonly used to estimate one-repetition maximums (1RMs). Proponents suggest these estimates can be obtained at high frequencies and assist with manipulating loads according to session-by-session fluctuations. Given their increasing popularity and development of associated technologies, a range of load-velocity approaches have been investigated. This systematic review and individual participant data (IPD) meta-analysis sought to quantify the predictive validity of individualised load-velocity relationships for the purposes of 1RM prediction. In September 2022, a search of MEDLINE, SPORTDiscus, Web of Science and Scopus was conducted for published research, with Google Scholar, CORE and the British Library's EThOS also searched for unpublished research. Studies were eligible if they were written in English, and directly compared a measured and predicted 1RM using load-velocity relationships in the squat, bench press, deadlift, clean, or snatch. IPD were obtained through requests to primary authors and through digitisation of in-text plots (e.g., Bland-Altman plots). Risk of bias of was assessed using a prediction model risk of bias tool (PROBAST) and the review conducted in accordance with PRISMA-IPD guidelines and an a priori protocol. Absolute and scaled standard error of the estimates (SEE/SEE%) were calculated for two-stage aggregate analyses, with bootstrapping performed for sampling variances. Estimates were pooled using three-level hierarchical models with robust 95% confidence intervals (CIs). One-stage analyses were conducted with random intercepts to account for systematic differences across studies and prediction residuals calculated in the absolute scale (kg) and as a percentage of the measured 1RM. Moderator analyses were conducted by including a priori defined categorical variables as fixed effects. One hundred and thirty-four models from 26 studies were included, with each identified as having low, unclear or high risk of bias. Twenty studies comprising 434 participants provided sufficient data for meta-analyses, with raw data obtained for 8 (32%) studies. Two-stage analyses identified moderate predictive validity (SEE% = 9.8 [95% CI: 7.4 to 12.3%]), with moderator analyses demonstrating limited differences based on the number of loads (ß2Loads:>2Loads= 0.01, [95% CI: -1.5 to 1.5%]) or the use of individual or group data to determine 1RM velocity thresholds (ßGroup:Individualised= -0.4 [95% CI: -1.9 to 1.1%]). One-stage analyses identified that predictions tended to be overestimations (4.3 [95% CI: 1.4 to 7.3 kg]), which expressed as a percentage of measured 1RM was equal to 3.6 [95% CI: 0.44 to 6.8%1RM]. Moderator analyses were consistent with those conducted for two-stage analyses. Load-velocity relationships tend to overestimate 1RMs irrespective of the modelling approach selected. Based on the findings from this review, practitioners should incorporate direct assessment of 1RM wherever possible. However, load-velocity relationships may still prove useful for general monitoring purposes (e.g. assessing trends across a training cycle), by providing high frequency estimates of 1RM when direct assessment may not be logistically feasible. Given limited differences in predictions across popular load-velocity approaches, it is recommended that practitioners opting to incorporate this practice select the modelling approach that best suits their practical requirements

The Effects of Sprint Interval Training on Physical Performance: A Systematic Review and Meta-Analysis

The present study aimed to synthesize findings from published research and through meta-analysis quantify the effect of sprint interval training (SIT) and potential moderators on physical performance outcomes (categorized as aerobic, anaerobic, mixed aerobic-anaerobic, or muscular force) with healthy adults, in addition to assessing the methodological quality of included studies and the existence of small study effects. Fifty-five studies were included (50% moderate methodological quality, 42% low methodological quality), with 58% comprising an intervention duration of ≤4 weeks and an array of different training protocols. Bayesian’s meta-analysis of standardized mean differences (SMD) identified a medium effect of improved physical performance with SIT (ES0.5 = 0.52; 95% credible intervals [CrI]: 0.42–0.62). Moderator analyses identified overlap between outcome types with the largest effects estimated for anaerobic outcomes (ES0.5 = 0.61; 95% CrI: 0.48–0.75). Moderator effects were identified for intervention duration, sprint length, and number of sprints performed per session, with larger effects obtained for greater values of each moderator. A substantive number of very large effect sizes (41 SMDs > 2) were identified with additional evidence of extensive small study effects. This meta-analysis demonstrates that short-term SIT interventions are effective for developing moderate improvements in physical performance outcomes. However, extensive small study effects, likely influenced by researchers analyzing many outcomes, suggest potential overestimation of reported effects. Future research should analyze fewer a priori selected outcomes and investigate models to progress SIT interventions for longer-term performance improvements

Effect of Ability and Style of Ascent on Psychophysiological Responses to Difficult On-sight Rock Climbing

Peer-reviewed abstract at a conferenc