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Purpose: To examine the effect of fast- versus slow-speed eccentric-muscle-action resistance training on lower-body strength, vertical jump height, sprint speed, and change-of-direction performance in elite soccer players during a competitive season. Methods: Twenty-two elite soccer players, from a single team, were randomly assigned to groups that undertook either 1- (fast speed) or 4-second (slow speed) eccentric resistance training during the in-season period. A 5-week program was conducted during an elite top-division European League soccer season. Performance measures including predicted 1-repetition-maximum back squat, countermovement jump, 20-m sprint, and change of direction were tested before and after the intervention period. Total match and training running distance and muscle soreness were also recorded during each week of the intervention. Results: An analysis of covariance showed significant group effects (P = .01) for countermovement jump with a greater jump height in the 1-second fast-speed group postintervention (95% CI, 1.1–6.9 cm). Despite an overall increase in 1-repetition maximum pretraining to posttraining (95% CI, 10.0–15.3 kg, effect size 0.69), there were no significant differences (P > .05) between groups after the intervention. Similarly, there were no differences between groups for change of direction, 20-m sprint, or muscle soreness. Conclusion: Faster eccentric muscle actions may be superior for increasing movements in elite soccer players in-season.

Longitudinal changes in anthropometric and physical performance characteristics of International female rugby union players were evaluated across 5-seasons, according to field position. Sixty-eight international female rugby union players from a top 2 ranked international team, undertook anthropometric and physical performance measurements across five seasons. Anthropometric and physical performance changes occurred, with skinfolds decreasing between 2015 and 2017 and body mass increasing between 2017 and 2019. Single-leg isometric squat (SL ISO), 0-10 m momentum (0-10 Mom) and 20-30 m momentum (20-30Mom) were higher in 2018 and 2019 than all years. Front-row players were characterised by greater SL ISO and 1-RM bench press than inside and outside backs, with higher skinfolds and lower endurance levels than all positions. Between 2017 and 2019, front-row players had larger decreases and increases in endurance and one repetition maximum (1-RM) bench press, respectively, compared to all other positions. Forwards had the highest 0-10Mom and 20-30Mom, and scrum-half the lowest, while outside backs had faster 0-10, 30-40, and 40 m (TT40 m) times, and greater peak velocity (Vmax) compared to forward positions. These longitudinal findings show that physical performance has increased, with anthropometric and performance characteristics becoming more distinctive between positions, among elite female rugby union players.

The aim of this investigation was to determine if acute or repeated applications of ischemic preconditioning (IPC) could enhance the recovery process, following exercise induced muscle damage (EIMD).Randomized control trial.Twenty-three healthy males were familiarised with the muscle damaging protocol (five sets of 20 drop jumps from a 0.6 m box) and randomly allocated to one of three groups: SHAM (3 × 5 min at 20 mmHg), Acute IPC (3 × 5 min at 220 mmHg) and Repeated IPC (3 days x 3 × 5 min at 220 mmHg). The indices of muscle damage measured included creatine kinase concentration ([CK]), thigh swelling, delayed onset muscle soreness, counter movement jumps (CMJ) and maximal voluntary isometric contraction (MVIC).Both acute and repeated IPC improved recovery in MVIC versus SHAM. Repeated IPC led to a faster MVIC recovery at 48 h (101.5%) relative to acute IPC (92.6%) and SHAM (84.4%) (P 0.05). Less swelling was found for both acute and repeated IPC vs. SHAM (P 0.05) but no group effects were found for CMJ, soreness or [CK] responses (P 0.05).Taken together, repeated IPC can enhance recovery time of MVIC more than an acute application, and both reduce swelling following EIMD, relative to a SHAM condition.

Lovegrove, S, Hughes, L, Mansfield, S, Read, P, Price, P, and Patterson, SD. Repetitions in reserve is a reliable tool for prescribing resistance training load. J Strength Cond Res 36(10): 2696-2700, 2022-This study investigated the reliability of repetitions in reserve (RIR) as a method for prescribing resistance training load for the deadlift and bench press exercises. Fifteen novice trained men (age: 17.3 ± 0.9 years, height: 176.0 ± 8.8 cm, body mass: 71.3 ± 10.7 kg) were assessed for 1 repetition maximum (1RM) for deadlift (118.1 ± 27.3 kg) and bench press (58.2 ± 18.6 kg). Subsequently, they completed 3 identical sessions (one familiarization session and 2 testing sessions) comprising sets of 3, 5, and 8 repetitions. For each repetition scheme, the load was progressively increased in successive sets until subjects felt they reached 1-RIR at the end of the set. Test-retest reliability of load prescription between the 2 testing sessions was determined using intraclass correlation coefficient (ICC) and coefficient of variation (CV). A 2-way analysis of variance with repeated measures was used for each exercise to assess differences in the load corresponding to 1-RIR within each repetition scheme. All test-retest comparisons demonstrated a high level of reliability (deadlift: ICC = 0.95-0.99, CV = 2.7-5.7% and bench press: ICC = 0.97-0.99, CV = 3.8-6.2%). Although there were no differences between time points, there was a difference for load corresponding to 1-RIR across the 3 repetition schemes (deadlift: 88.2, 84.3, and 79.2% 1RM; bench press: 93.0, 87.3, and 79.6% 1RM for the 3-, 5-, and 8-repetition sets, respectively). These results suggest that RIR is a reliable tool for load prescription in a young novice population. Furthermore, the between-repetition scheme differences highlight that practitioners can effectively manipulate load and volume (repetitions in a set) throughout a training program to target specific resistance training adaptations.

Uddin, N, Jeffries, O, Read, P, Howe, L, Patterson, S, and Waldron, M. Physiological responses to linear and nonlinear soccer-specific match simulations and their effects on lower-limb muscle fatigue. J Strength Cond Res 34(11): 3232-3240, 2020-The aims of this study were to: (a) investigate the effects of linear and nonlinear soccer simulations on lower-limb muscle function and physiological responses and (b) evaluate the relationship between match-running demands and changes in lower-limb muscle function. In a repeated-measures cross-over design, 8 participants completed either a linear or nonlinear adapted Loughborough Intermittent Shuttle Test (LIST) on 2 occasions. The movement of players was tracked with a global positioning system, while lower-limb muscle function tests and physiological measurements were performed before and every 15 minutes during the simulation. There were no differences in distance covered, yet high-speed running (p = 0.007), accelerations (p = 0.008), and decelerations (p = 0.015) were higher in the linear LIST. Mean heart rate (p = 0.001) and ratings of perceived exertion (p = 0.013) were higher in the nonlinear LIST. Peak landing forces (p = 0.017) and jump height (p = 0.001) were reduced between baseline and 90 minutes but were not different between conditions. Changes in peak landing forces from baseline to half-time (r = -0.57, n = 16, p = 0.022) and full-time (r = -0.58, n = 16, p = 0.019) were related to high-speed running. Hamstring force was unaffected by time (p = 0.448) but was reduced in the linear LIST (p = 0.044). Protocols posing different external and internal demands elicited similar levels of fatigue across simulations. Hamstring function was not an effective indicator of fatigue, but our results highlight the greater demands placed on this muscle group when higher-speed running is performed.

\ud Objective – There is a high incidence of concussion and frequent utilization of Rapid Weight Loss (RWL) methods among combat sport athletes, yet the apparent similarity in symptoms experienced as a result of a concussion or RWL has not been investigated. This study surveyed combat sports athletes to investigate the differences in symptom-onset and recovery between combat sports and evaluated the relationships between concussion and RWL symptoms.\ud Design – Cross-Sectional Study\ud Setting – Data were collected via an online survey.\ud Participants – 132 (male 115, female 17) combat sport athletes.\ud Interventions – Modified Sport Concussion Assessment Tool (SCAT) symptom checklist and weight-cutting questionnaire.\ud Main Outcome Measures – Survey items included combat sport discipline, weight loss, and medical history, weight-cutting questionnaire, and concussion & weight-cutting symptom checklists.\ud Results – Strong associations (rs = 0.6 – 0.7, p < 0.05) were observed between concussion and RWL symptoms. The most frequently reported symptom resolution times were 24 - 48 h for a weight-cut (WC; 59%) and 3 - 5 days for a concussion (43%), with 60 - 70% of athletes reporting a deterioration and lengthening of concussion symptoms when undergoing a WC. The majority of athletes (65%) also reported at least one WC in their career to ‘not go according to plan’, resulting in a lack of energy (83%) and strength/power (70%).\ud Conclusions – RWL and concussion symptoms are strongly associated, with the majority of athletes reporting a deterioration of concussion symptoms during a WC. The results indicate that concussion symptoms should be monitored alongside hydration status to avoid any compound effects of prior RWL on the interpretation of concussion assessments and to avoid potential misdiagnoses among combat athletes.

Ischaemic preconditioning (IPC) has emerged as a potential non-invasive ergogenic aid to enhance exercise performance. Repeated application of IPC has demonstrated clinical efficacy, therefore our aims were to investigate its effect on endurance cycling performance and muscle efficiency. Twenty participants undertook 7-d repeated bilateral lower limb occlusion (4 x 5-min) of IPC (220 mmHg) or sham (20 mmHg). Prior to and 72-h following the intervention, participants performed submaximal cycling at 70, 80 and 90% of ventilatory threshold (VT) followed by an incremental exercise test. IPC had no effect on

Explosive actions are integral to soccer performance and highly influenced by the ability to generate maximal power. The purpose of this study was to investigate the relationship between force-velocity profile, jump performance, acceleration and maximal sprint speed in elite female soccer players. Thirty-nine international female soccer players (24.3±4.7 years) performed 40-m sprints, maximal countermovement jumps and five loaded squat jumps at increasing loads to determine individual force-velocity profiles. Theoretical maximal velocity, theoretical maximal force, maximal power output, one repetition maximal back squat and one repetition maximal back squat relative to body mass were determined using the force-velocity profile. Counter movement jump, squat jump and maximal power output demonstrated moderate to large correlation with acceleration and maximal sprint speed (r=− 0.32 to −0.44 and −0.32 to −0.67 respectively, p0.05). Vertical force-velocity profiling and maximal strength can provide valuable insight into the neuromuscular qualities of an athlete to individualize training, but the ability to produce force, maximal power, and further transference into sprint performance, must be central to program design.

Objectives This study aimed to evaluate changes in rugby union physical match characteristics across five seasons of International female competition, according to position and opposition quality. Design & methods Global positional systems and performance analysis data from 78 female rugby union players (minimum of five international appearances) were analysed between 2015 and 2019. Mixed-linear-modelling was used to investigate the effects of season, opposition and position during 969 individual match performances from 53 International matches. Results Running demands increased between 2015 and 2017 (World Cup year) and plateaued thereafter, except for sprints among the outside backs, which declined between 2017 and 2019, and accelerations and decelerations >3 m s2 which increased between 2017 and 2019. Collisions were higher in forwards than backs, and highest against stronger opposition. Running demands were greater against weaker opposition, but the ‘most intense periods’ of running were greater against stronger opposition in 2017. Conclusions Match demands increased between 2015 and the 2017 World Cup year, which was underpinned by increased sprinting and greater running during maximum intensity periods against top 5 opposition. The increase in accelerations and decelerations in the latter years, alongside the maintenance of average running demands and collision counts, is consistent with the reported continuous playing style of female rugby, thus placing specific demands on players and requiring tailored training methods. Some positions (Forwards and Scrum-halves) appear to be important for this adopted style, demonstrating concomitantly high relative collision and running intensities.

Context: Neuromuscular electrical stimulation (NMES) combined with blood flow restriction (BFR) has been shown to improve muscular strength and size better than NMES alone. However, previous studies used varied methodologies not recommended by previous NMES or BFR research. Objective: The present study investigated the acute effects of NMES combined with varying degrees of BFR using research-recommended procedures to enhance understanding and the clinical applicability of this combination. Design: Randomized crossover. Setting: Physiology laboratory. Participants: A total of 20 healthy adults (age 27 [4] y; height 177 [8] cm; body mass 77 [13] kg). Interventions: Six sessions separated by at least 7 days. The first 2 visits served as familiarization, with the experimental conditions performed in the final 4 sessions: NMES alone, NMES 40% BFR, NMES 60% BFR, and NMES 80% BFR. Main Outcome Measures: Maximal voluntary isometric contraction, muscle thickness, blood pressure, heart rate, rating of perceived exertion, and pain were all recorded before and after each condition. Results: The NMES 80% BFR caused greater maximal voluntary isometric contraction decline than any other condition (−38.9 [22.3] N·m, P P P Conclusion: The NMES combined with 80% BFR caused greater acute force decrement than the other conditions. However, greater perceptual ratings of pain and ratings of perceived exertion were observed with NMES 80% BFR. These acute observations must be investigated during chronic interventions to corroborate any relationship to changes in muscle strength and size in clinical populations.

Taurine is central to many physiological processes, some of which are augmented by exogenous supply and have the potential to facilitate endurance performance; however, its independent effects on performance have not been systematically analysed. To evaluate the effects of isolated oral taurine ingestion on endurance performance and to assess the contribution of (1) the dose and (2) the supplementation period to the ergogenic effect. A search was performed using various databases in September 2017. The studies were screened using search criteria for eligibility. Ten peer-reviewed articles were identified for inclusion. A sub-analysis of time-to-exhaustion (TTE) trials (n = 7) was also performed. The effects of (1) dose and (2) the acute (single dose) or chronic (> 1 day) supplementation periods were assessed using meta-regression. The doses of taurine ranged from 1 to 6 g/day and were provided in single doses and for up to 2 weeks among a range of subjects. Taurine ingestion improved overall endurance performance (Hedges’ g = 0.40, 95% CI 0.12–0.67, P = 0.004), which was similar in TTE trials (Hedges’ g = 0.43, 95% CI 0.12–0.75, P = 0.007). There were no differences between acute or chronic supplementation for the full sample (P = 0.897) or the TTE group (P = 0.896). The dose of taurine did not moderate its effect on endurance performance (P > 0.05). Human endurance performance can be improved by orally ingesting a single dose of taurine in varying amounts (1–6 g).

Purpose:To investigate the effects of caffeine (C), taurine (T), caffeine and taurine coingestion (C +T), or placebo (P) on repeated Wingate cycling performance and associated physiological responses.Methods:Seven male team-sport players participated in a randomized, single-blind, crossover study, where they completed 3 Wingate tests, each separated by 2 min, an hour after ingesting: C (5 mg/kg body mass [BM]), T (50 mg/kg BM), C +T (5 mg/kg BM + 50 mg/kg BM), or P (5 mg/kg BM) in a gelatin capsule. Performance was measured on an ergometer, and blood lactate, perceived exertion, heart rate (HR), mean arterial pressure (MAP), and rate pressure product (RPP) were measured at rest (presupplement), baseline (1 h postsupplement), and during and after exercise.Results:Magnitude-based inferences revealed that all of the supplements increased (smalltomoderate, likely to very likely) mean peak power (MPP), peak power (PP), and mean power (MP) compared to P, with greater MPP, PP, and MP in T compared to C (small, possible). Intrasprint fatigue index (%FIIntra) was greater in T compared to P and C (moderate, likely), and %FIInterwas lower in T compared to C (small, possible). C and C +T increased HR, MAP, and RPP compared to P and T at baseline (moderate tovery large, likely to most likely); however, these only remained higher in C compared to all conditions in the final sprint.Conclusions:T elicited greater improvements in performance compared to P, C, or C +T while reducing the typical chronotropic and pressor effects of C.

he aims of the study were to investigate: 1) fluctuations in kinematic and locomotor-based metabolic power estimates during elite-level under-21 soccer matches and 2) the relationship between temporary fatigue during matches and heart rate (HR) responses to the YO-YO intermittent recovery test 1 (YO-YO IR1). High speed running (HSR), high metabolic load (HML) distances and average metabolic power (AMP) data were collected from 13 elite soccer players during six matches using global positioning systems. Indices of heart rate recovery (HRR60s; HR60s; %HRR60s) were assessed after a submaximal (YO-YO IR1). The peak 5-min period of matches was higher than both the subsequent 5-min period and the match average for all physical variables (P < 0.001). HML distance was greater (P < 0.001) in peak, post-peak and mean 5-min periods compared to HSR. Peak intensity HML distance was related to %HRR60s (r = -0.331) but not AMP (r = -0.273) or HSR distance (r = -0.224). HML distance should be used to monitor fluctuations in intensity during soccer matches. HRR measured after a submaximal YO-YO IR1 has limited potential, in the assessment of the match specific fitness of players.

Blood flow restriction (BFR) has been shown to produce beneficial adaptations to skeletal muscle. These adaptations have been documented in the civilian and military populations. BFR therapy may provide patients a safe method to begin strength training at earlier stages of rehabilitation to allow for earlier and more effective return to activity and improved military readiness. The purpose was to review BFR therapy physiology, complications, side effects, standardized treatment algorithms, and long-term patient outcomes.

We implemented a blood flow restriction resistance training (BFR-RT) intervention during an 8-week rehabilitation programme in anterior cruciate ligament reconstruction (ACLR) patients within a National Health Service setting. To compare the effectiveness of BFR-RT and standard-care traditional heavy-load resistance training (HL-RT) at improving skeletal muscle hypertrophy and strength, physical function, pain and effusion in ACLR patients following surgery. 28 patients scheduled for unilateral ACLR surgery with hamstring autograft were recruited for this parallel-group, two-arm, single-assessor blinded, randomised clinical trial following appropriate power analysis. Following surgery, a criteria-driven approach to rehabilitation was utilised and participants were block randomised to either HL-RT at 70% repetition maximum (1RM) (n = 14) or BFR-RT (n = 14) at 30% 1RM. Participants completed 8 weeks of biweekly unilateral leg press training on both limbs, totalling 16 sessions, alongside standard hospital rehabilitation. Resistance exercise protocols were designed consistent with standard recommended protocols for each type of exercise. Scaled maximal isotonic strength (10RM), muscle morphology of the vastus lateralis of the injured limb, self-reported function, Y-balance test performance and knee joint pain, effusion and range of motion (ROM) were assessed at pre-surgery, post-surgery, mid-training and post-training. Knee joint laxity and scaled maximal isokinetic knee extension and flexion strength at 60°/s, 150°/s and 300°/s were measured at pre-surgery and post-training. Four participants were lost, with 24 participants completing the study (12 per group). There were no adverse events or differences between groups for any baseline anthropometric variable or pre- to post-surgery change in any outcome measure. Scaled 10RM strength significantly increased in the injured limb (104 ± 30% and 106 ± 43%) and non-injured limb (33 ± 13% and 39 ± 17%) with BFR-RT and HL-RT, respectively, with no group differences. Significant increases in knee extension and flexion peak torque were observed at all speeds in the non-injured limb with no group differences. Significantly greater attenuation of knee extensor peak torque loss at 150°/s and 300°/s and knee flexor torque loss at all speeds was observed with BFR-RT. No group differences in knee extensor peak torque loss were found at 60°/s. Significant and comparable increases in muscle thickness (5.8 ± 0.2% and 6.7 ± 0.3%) and pennation angle (4.1 ± 0.3% and 3.4 ± 0.1%) were observed with BFR-RT and HL-RT, respectively, with no group differences. No significant changes in fascicle length were observed. Significantly greater and clinically important increases in several measures of self-reported function (50-218 ± 48% vs. 35-152 ± 56%), Y-balance performance (18-59 ± 22% vs. 18-33 ± 19%), ROM (78 ± 22% vs. 48 ± 13%) and reductions in knee joint pain (67 ± 15% vs. 39 ± 12%) and effusion (6 ± 2% vs. 2 ± 2%) were observed with BFR-RT compared to HL-RT, respectively. BFR-RT can improve skeletal muscle hypertrophy and strength to a similar extent to HL-RT with a greater reduction in knee joint pain and effusion, leading to greater overall improvements in physical function. Therefore, BFR-RT may be more appropriate for early rehabilitation in ACLR patient populations within the National Health Service.

Examine the comfort and pain experienced with blow flow restriction resistance training (BFR-RT) compared to standard care heavy load resistance training (HL-RT) during anterior cruciate ligament reconstruction (ACLR) patient rehabilitation. Randomised controlled trial. United Kingdom National Health Service. Twenty eight patients undergoing unilateral ACLR surgery with hamstring autograft were recruited. Following surgery participants were block randomised to either HL-RT at 70% repetition maximum (1RM) (n = 14) or BFR-RT (n = 14) at 30% 1RM and completed 8 weeks of twice weekly unilateral leg press training on both limbs. Perceived knee pain, muscle pain and rating of perceived exertion (RPE) were assessed using Borg's (1998) RPE and pain scales during training. Knee pain was also assessed 24 h post-training. There were no adverse events. Knee pain was lower with BFR-RT during (p 0.05) for both BFR-RT and HL-RT. ACLR patients experienced less knee joint pain and reported similar ratings of perceived exertion during and following leg press exercise with BFR-RT compared to traditional HL-RT. BFR-RT may be more advantageous during the early phases of post-surgery ACLR rehabilitation. [Abstract copyright: Copyright © 2019. Published by Elsevier Ltd.]

Waddingham, DP, Millyard, A, Patterson, SD, and Hill, J. Effect of ballistic potentiation protocols on elite sprint swimming: optimizing performance. J Strength Cond Res 35(10): 2833-2838, 2021-Warming-up before an athletic event is important for performance; however, in some competition scenarios, there is a long wait between completing the warm-up and the event. Thus, potentiation protocols are becoming increasingly popular in a competition environment. The aim of the study was to determine the effects of practical potentiation protocols on 15-m start performance in national level swimmers. Eleven national level swimmers participated in the study. Using a randomized cross-over design, subjects completed a 15-m swimming start following 4 different experimental conditions (swim-specific control, resisted band squat, weighted countermovement jumps, and drop jumps from a 45-cm box), each separated by at least 48 hours. A repeated-measures analysis of variance showed a significant difference in 15-m swimming start performance following different warm-up protocols (F(1.646, 14.810) = 6.968, p = 0.01). A post hoc Bonferroni test indicated that 15-m start time was significantly quicker with the band squat protocol compared with the swim-specific protocol (6.65 ± 0.43 vs. 6.78 ± 0.43 seconds, respectively, p = 0.04). The results conclude that practical potentiation protocols are able to enhance 15-m swim start performance when combined with a swim-specific warm-up and supports the use of postactivation potentiation during competitive swimming environments.

Madison, G, Patterson, SD, Read, P, Howe, L, and Waldron, M. Effects of small-sided game variation on changes in hamstring strength. J Strength Cond Res 33(3): 839-845, 2019-Small-sided games (SSGs) are commonly used by soccer practitioners to condition players. This form of exercise can result in fatigue, potentially exposing the muscle to injury risk. The purpose of this study was to determine the effects of SSG variations on hamstring torque in semiprofessional soccer players. In a counterbalanced cross-over design, 10 male semiprofessional soccer players took part in both small relative area (3 vs. 3; 300 m) and large relative area (4 vs. 4; 1000 m) SSGs. The games comprised 6 × 4-minute bouts, with 90-second recovery. Both movement and heart rate responses were monitored by global positioning systems (GPS) and hamstring isometric torque was measured pre-training and post-training using a NordBord. There were differences (p < 0.05) between the small and large relative area games for peak hamstring force decrement (5.78 N and -13.62 N, respectively) and mean hamstring force decrement at 90° (11.11 N and -4.78 N, respectively). The number of accelerations was related to (r = 0.46, p = 0.039) reduced hamstring peak torque at 90°. In conclusion, larger relative area SSGs elicited the greatest internal and external loads, resulting in decrements in hamstring force. The number of accelerations performed in the session increases the likelihood of hamstring fatigue and can be controlled with the relative pitch area.

This study investigated the effects of a mentally-fatiguing test on physical tasks among elite cricketers. In a cross-over design, ten elite male cricket players from a professional club performed a cricket run-two test, a Batak-lite reaction time test and a Yo-Yo-Intermittent Recovery Level 1 (Yo-Yo-IR1) test, providing a rating of perceived exertion (RPE) after completing a 30-min Stroop test (mental fatigue condition) or 30-min control condition. Perceived fatigue was assessed before and after the two conditions and motivation was measured before testing. There were post-treatment differences in the perception of mental fatigue (P < 0.001; d = -7.82, 95% CIs = -9.05 to 6.66; most likely). Cricket run-two (P = 0.002; d = -0.51, 95% CIs = -0.72 to 0.30; very likely), Yo-Yo-IR1 distance (P = 0.023; d = 0.39, 95% CIs = 0.14 to 0.64; likely) and RPE (P = 0.001; d = -1.82, 95% CIs = -2.49 to 1.14; most likely) were negatively affected by mental fatigue. The Batak lite test was not affected (P = 0.137), yet a moderate (d = 0.41, 95% CIs = -0.05 to 0.87) change was likely. Mental fatigue, induced by an app-based Stroop test, negatively affected cricket-relevant performance.

Purpose: Recovery from lower limb fracture, surgery or injury often requires a period of immobilisation, which leads to significant declines in muscular strength and size, ranging from 0.3–4.2% per day. A common technique used to attenuate muscle atrophy during immobilisation is neuromuscular electrical stimulation (NMES). However, a more recently utilised intervention is blood flow restriction (BFR). During immobilisation, isolated NMES and BFR have both been shown to reduce muscular atrophy, but not strength declines. Recently, NMES combined with BFR has been investigated and led to increased muscular strength and size in healthy participants and those with spinal cord injuries, compared with NMES and BFR alone. The mechanisms and safety of NMES combined with BFR is currently unknown. The aim of the present study was to discover the acute effects of NMES combined with varying degrees of BFR on muscular, cardiovascular and perceptual variables.

Jeffries, O, Simmons, R, Patterson, SD, and Waldron, M. Functional threshold power is not equivalent to lactate parameters in trained cyclists. J Strength Cond Res 35(10): 2790-2794, 2021-Functional threshold power (FTP) is derived from a maximal self-paced 20-minute cycling time trial whereby the average power output is scaled by 95%. However, the physiological basis of the FTP concept is unclear. Therefore, we evaluated the relationship of FTP with a range of laboratory-based blood lactate parameters derived from a submaximal threshold test. Twenty competitive male cyclists completed a maximal 20-minute time trial and an incremental exercise test to establish a range of blood lactate parameters. Functional threshold power (266 ± 42 W) was strongly correlated (r = 0.88, p0.001) with the power output associated with a fixed blood lactate concentration 4.0 mmol·L-1 (LT4.0) (268 ± 30 W) and not significantly different (p0.05). While mean bias was 2.9 ± 24.6 W, there were large limits of agreement (LOA) between FTP and LT4.0 (-45 to 51 W). All other lactate parameters, lactate threshold (LT) (236 ± 32 W), individual anaerobic threshold (244 ± 33 W), and LT thresholds determined using the Dmax method (221 ± 25 W) and modified Dmax method (238 ± 32 W) were significantly different from FTP (p0.05). While FTP strongly correlated with LT4.0, the large LOA refutes any equivalence as a measure with physiological basis. Therefore, we would encourage athletes and coaches to use alternative field-based methods to predict cycling performance.

La validite du dispositif TritonWear® pour mesurer les performances en natation a ete etudiee avec un objectif analytique predetermine de 6 %. Vingt jeunes nageurs ont realise une epreuve de 100 m dans une piscine de 25 m, ® en brasse ou en nage libre en portant le dispositif TritonWear, tout en etant filmes au-dessus et en dessous de l’eau avec trois cameras. Les limites de concordance a 95 % (LoA a 95 %) et le coefficient de variation (CV %) ont ete utilises pour calculer l’erreur. Des biais systematiques (p < 0,05) ont ete trouves entre les deux systemes uniquement pour la distance parcourue par coup de bras en brasse. La concordance des metriques en nage libre variait entre 1,06 % et 10,40 % du CV, sauf pour la distance par coup de bras (CV = 14,64 %) et le temps passe sous l’eau (CV = 18,15 %). Les valeurs pour la brasse variaient entre 0,95 % et 13,74% du CV, sauf pour le temps passe sous l’eau (CV = 25,76 %). Les plus petites erreurs ont ete trouvees pour les temps intermediaires, la vitesse, le nombre de coups de bras et la frequence des coups de bras, pour les deux nages (tous < 5 % de CV). Le TritonWear® peut etre utilise pour les mesures de performance de base, telles que le temps intermediaire et la vitesse, mais l’erreur sur des parametres plus complexes, telles que la duree d’immersion ou les temps de virage, ne permet pas d’identifier des modifications de ces parametres.

BACKGROUND The aim of this study was to compare the effect of local and remote ischemic preconditioning (IPC) on repeated sprint exercise. METHODS Twelve males (age 22±2 years; stature 1.79±0.07 m; body mass 77.8±8.4 kg; mean±SD) completed four trials consisting of remote (arm) and local (leg) IPC and SHAM interventions prior to repeated sprint exercise (3x[6x15+15-m] shuttle sprints), in a double-blind, randomized, crossover designed study. These tests were immediately preceded by IPC (4x5-minute intervals at 220 mmHg bilateral occlusion) or SHAM treatment (4x5-minute intervals at 20 mmHg bilateral occlusion). Sprint performance and percentage decrement score alongside measurement of Tissue Saturation Index, blood lactate and RPE were measured throughout the intervention. RESULTS During the IPC/SHAM intervention there was a large decrease in TSI for IPC-arm in comparison to IPC-leg (P

Objectives\ud To compare the acute perceptual and blood pressure responses to: 1) light load blood flow restriction resistance exercise (BFR-RE) in non-injured individuals and anterior cruciate ligament reconstruction (ACLR) patients; and 2) light load BFR-RE and heavy load RE (HL-RE) in ACLR patients.\ud \ud Design\ud Between-subjects, partially-randomised.\ud \ud Methods\ud This study comprised 3 groups: non-injured BFR-RE (NI-BFR); ACLR patients BFR-RE (ACLR-BFR); ACLR patients HL-RE (ACLR-HL). NI-BFR and ACLR-BFR performed 4 sets (30, 15, 15, 15 reps, total=75 reps, 30s inter-set rest) of unilateral leg press exercise at 30% 1RM with continuous BFR at 80% limb occlusive pressure. ACLR-HL performed 3 x 10 reps (Total=30 reps, 30s inter-set rest) of unilateral leg press exercise at 70% 1RM. Perceived exertion (RPE), muscle pain, knee pain and pre- and 5-min post-exercise blood pressure were measured.\ud \ud Results\ud RPE was higher in ACLR-BFR compared to NI-BFR (p

Nevin, JP, Smith, P, Waldron, M, Patterson, S, Price, M, Hunt, A, and Blagrove, R. Efficacy of an 8-week concurrent strength and endurance training program on hand cycling performance. J Strength Cond Res 32(7): 1861-1868, 2018-The aim of this study was to investigate the effects of an 8-week concurrent strength and endurance training program in comparison with endurance training only on several key determinants of hand cycling performance. Five H4 and 5 H3 classified hand cyclists with at least 1 year's hand cycling training history consented to participate in the study. Subjects underwent a battery of tests to establish body mass, body composition, V[Combining Dot Above]O2peak, maximum aerobic power, gross mechanical efficiency (GME), maximal upper-body strength, and 30-km time-trial performance. Subjects were matched into pairs based on 30-km time-trial performance and randomly allocated to either a concurrent strength and endurance or endurance training only, intervention group. After an 8-week training program based on a conjugated block periodization model, subjects completed a second battery of tests. A mixed model, 2-way analysis of variance revealed no significant changes between groups. However, the calculation of effect sizes (ESs) revealed that both groups demonstrated a positive improvement in most physiological and performance measures with subjects in the concurrent group demonstrating a greater magnitude of improvement in body composition (ES -0.80 vs. -0.22), maximal aerobic power (ES 0.97 vs. 0.28), GME (ES 0.87 vs. 0.63), bench press 1 repetition maximum (1RM) (ES 0.53 vs. 0.33), seated row 1RM (ES 1.42 vs. 0.43), and 30-km time-trial performance (ES -0.66 vs. -0.30). In comparison with endurance training only, an 8-week concurrent training intervention based on a conjugated block periodization model seems to be a more effective training regime for improving the performance capabilities of hand cyclists.

To determine the effect of performing depth jumps (DJ) pre-exercise on running economy (RE) and time to exhaustion (TTE) at the speed associated with maximal oxygen uptake (sV˙O ) in a group of high-performing junior middle-distance runners. Randomized crossover study. Seventeen national- and international-standard male distance runners (17.6±1.2years, 63.4±6.3kg, 1.76±0.06m, 70.7±5.2mLkg min ) completed two trials. Following a 5min warm-up at 60% V˙O , participants performed a 5min run at 20%Δ below oxygen uptake corresponding with lactate turn-point to determine pre-intervention RE. Participants then completed either six DJ from a box equivalent to their best counter-movement jump (CMJ) or a control condition (C) involving body weight quarter squats. After a 10min passive recovery, another 5min sub-maximal run was performed followed by a run to exhaustion at sV˙O . Compared to the C trial, DJ produced moderate improvements (-3.7%, 95% confidence interval for effect size: 0.25-1.09) in RE, which within the context of minimal detectable change is considered possibly beneficial. Differences in TTE and other physiological variables were most likely trivial (ES

Jeffries, O, Hill, J, Patterson, SD, and Waldron, M. Energy drink doses of caffeine and taurine have a null or negative effect on sprint performance. J Strength Cond Res 34(12): 3475-3481, 2020-This study investigated the effects of caffeine and taurine coingestion on repeat-sprint cycling performance and associated physiological and perceptual responses. In a double-blind, cross-over, repeated measures study, 11 male subjects (age 21 ± 2 years; stature 178 ± 7 cm; body mass 80 ± 13 kg) completed 10 × 6-second sprints on a cycle ergometer, each separated by 24 seconds, one hour after ingesting: caffeine (80 mg) and taurine (1 g), equivalent to the amount observed in popular commercial energy drinks, or placebo (maltodextrin ∼1 g) in a gelatine capsule. Performance was measured on a cycle ergometer, whereas blood lactate concentration (B[la]), rating of perceived exertion (RPE), and heart rate (HR) were measured at baseline (pre-exercise) and after sprints 5 and 10. Magnitude-based inferences revealed likely, trivial differences in peak power and unclear, trivial intersprint fatigue index after ingestion of the caffeine and taurine supplement. Intrasprint fatigue was greater in the caffeine and taurine condition at sprint 10 (likely, small) and possibly smaller in sprints 6-9. The caffeine and taurine supplement had a likely large effect on HR at baseline (effect size = 0.94) and increases in B[la] after sprints 5 (likely small) and 10 (possibly small). There was no effect of the supplement on RPE (unclear, trivial). Administration of caffeine and taurine at doses equivalent to commercial energy drinks did not improve repeat-sprint cycling performance and seemed to induce greater fatigue within selected sprints, particularly at the end of the trial. This undesirable performance effect occurs in parallel with increased HR and glycolytic metabolic bi-products.

This study tested the hypothesis that ischemic preconditioning (IPC) would increase critical power (CP) during a 3 minute all-out cycling test. Twelve males completed two 3 minute all-out cycling tests, in a crossover design, separated by 7 days. These tests were preceded by IPC (4 x 5 minute intervals at 220 mmHg bilateral leg occlusion) or SHAM treatment (4 x 5 minute intervals at 20 mmHg bilateral leg occlusion). CP was calculated as the mean power output during the final 30 s of the 3 minute test with W' taken as the total work done above CP. Muscle oxygenation was measured throughout the exercise period. There was a 15.3 ± 0.3% decrease in muscle oxygenation (TSI; [Tissue saturation index]) during the IPC stimulus, relative to SHAM. CP was significantly increased (241 ± 65 W vs. 234 ± 67 W), whereas W' (18.4 ± 3.8 vs 17.9 ± 3.7 kJ) and total work done (TWD) were not different (61.1 ± 12.7 vs 60.8 ± 12.7 kJ), between the IPC and SHAM trials. IPC enhanced CP during a 3 minute all-out cycling test without impacting W' or TWD. The improved CP after IPC might contribute towards the effect of IPC on endurance performance.

Strength training forms a pivotal part of rehabilitation. Heavy-load strength training (60%–70% one-repetition maximum (1RM)) has been traditionally prescribed to improve muscle strength, body mass and function,1 but may be unattainable and/or confer increased risk of adverse consequences in individuals with a musculoskeletal (MSK) impairment. The challenge faced by clinical practitioners is how to effectively and safely adapt training loads throughout rehabilitation. In the past decade, research has proven that blood flow restriction (BFR) during light-load training (eg, 20%–30% 1RM) can produce significant gains in muscle strength and size in healthy populations, in contrast to non-BFR load-matched controls.2 In this novel training method, limb blood flow is restricted via a cuff throughout the contraction cycle and rest period. This results in partial restriction of arterial inflow to muscle, but, most significantly restricts venous outflow from muscle. Given the light-load nature and strengthening capacity …

The aim of this study was to investigate the effects of caffeine supplementation on peak anaerobic power output (Wmax). Using a counterbalanced, randomised, double-blind, placebo-controlled design, 14 well-trained men completed three trials of a protocol consisting of a series of 6-s cycle ergometer sprints, separated by 5-min passive recovery periods. Sprints were performed at progressively increasing torque factors to determine the peak power/torque relationship and Wmax. Apart from Trial 1 (familiarisation), participants ingested a capsule containing 5 mg·kg(-1) of caffeine or placebo, one hour before each trial. The effects of caffeine on blood lactate were investigated using capillary samples taken after each sprint. The torque factor which produced Wmax was not significantly different (p ≥ 0.05) between the caffeine (1.15 ± 0.08 N·m·kg(-1)) and placebo (1.13 ± 0.10 N·m·kg(-1)) trials. There was, however, a significant effect (p < 0.05) of supplementation on Wmax, with caffeine producing a higher value (1885 ± 303 W) than placebo (1835 ± 290 W). Analysis of the blood lactate data revealed a significant (p < 0.05) torque factor × supplement interaction with values being significantly higher from the sixth sprint (torque factor 1.0 N·m·kg(-1)) onwards following caffeine supplementation. The results of this study confirm previous reports that caffeine supplementation significantly increases blood lactate and Wmax. These findings may explain why the majority of previous studies, which have used fixed-torque factors of around 0.75 N·m·kg(-1) and thereby failing to elicit Wmax, have failed to find an effect of caffeine on sprinting performance.

Background and objective: Low-load exercise training\ud with blood flow restriction (BFR) can increase muscle\ud strength and may offer an effective clinical musculoskeletal\ud (MSK) rehabilitation tool. The aim of this review\ud was to systematically analyse the evidence regarding the\ud effectiveness of this novel training modality in clinical\ud MSK rehabilitation.\ud Design: This is a systematic review and meta-analysis\ud of peer-reviewed literature examining BFR training\ud in clinical MSK rehabilitation (Research Registry;\ud researchregistry91).\ud Data sources: A literature search was conducted across\ud SPORTDiscus (EBSCO), PubMed and Science Direct\ud databases, including the reference lists of relevant papers.\ud Two independent reviewers extracted study characteristics\ud and MSK and functional outcome measures. Study\ud quality and reporting was assessed using the Tool for the\ud assEssment of Study qualiTy and reporting in EXercise.\ud Eligibility: Search results were limited to exercise\ud training studies investigating BFR training in clinical MSK\ud rehabilitation, published in a scientific peer-reviewed\ud journal in English.\ud Results: Twenty studies were eligible, including ACL\ud reconstruction (n=3), knee osteoarthritis (n=3), older\ud adults at risk of sarcopenia (n=13) and patients with\ud sporadic inclusion body myositis (n=1). Analysis of\ud pooled data indicated low-load BFR training had\ud a moderate effect on increasing strength (Hedges’\ud g=0.523, 95%CI 0.263 to 0.784, p

The purpose of the study was to examine the health effects of 8 weeks of recreational badminton in \ud untrained women. Participants were matched for maximal oxygen uptake (V̇ O2max) and body fat \ud percentage and assigned to either a badminton (n = 14), running (n = 14) or control group (n = 8). \ud Assessments were conducted pre- and post-intervention with physiological, anthropometric, \ud motivation to exercise and physical self-esteem data collected. Post-intervention, V̇ O2max increased \ud (P < 0.05) by 16% and 14% in the badminton and running groups, respectively, and time to \ud exhaustion increased (P < 0.05) by 19% for both interventions. Maximal power output was \ud increased (P < 0.05) by 13% in the badminton group only. Blood pressure, resting heart rate and \ud heart rate during submaximal running were lower (P < 0.05) in both interventions. Perceptions of \ud physical conditioning increased (P < 0.05) in both interventions. There were increases (P < 0.05) in \ud enjoyment and ill health motives in the running group only, whilst affiliation motives were higher \ud (P < 0.05) for the badminton group only. Findings suggest that badminton should be considered a \ud strategy to improving the health and wellbeing of untrained females who are currently not meeting \ud physical activity guidelines

Objectives The purpose of this investigation was to examine the effectiveness of intermittent lower limb occlusion in augmenting recovery from exercise induced muscle damage (EIMD) in physically active males. Design Randomized controlled trial, double blind. Methods Sixteen healthy recreationally active male participants were randomly assigned to an intermittent occlusion (OCC; n = 8) or control (SHAM; n = 8) group. The EIMD protocol comprised of 100 drop-jumps, from a 0.6 m box. Indices of muscle damage were creatine kinase (CK), thigh-circumference (TC), muscle soreness (DOMS), counter-movement jump (CMJ) and maximal isometric voluntary contraction (MIVC). Measurements were assessed pre, 24 h, 48 h and 72 h following exercise. Results There was a significant time effect for all indices of muscle damage suggesting EIMD was present following the exercise protocol. The decrease in MIVC was significantly attenuated in the OCC group compared to the SHAM group at 24 (90.4 ± 10.7 vs. 81.5 ± 6.7%), 48 (96.2 ± 6.1 vs. 84.5 ± 7.1%) and 72 h (101.1 ± 4.2 vs. 89.7 ± 7.5%). The CK response was reduced in the OCC group at 24 (335 ± 87 vs. 636 ± 300 IU) and 48 h (244 ± 70 vs. 393 ± 248 IU), compared to the SHAM group. DOMS was significantly lower in the OCC compared to the SHAM group at 24, 48 and 72 h post EIMD. There was no effect of OCC on CMJ or TC. Conclusions This investigation shows that intermittent lower limb occlusion administered after a damaging bout of exercise reduces indices of muscle damage and accelerates the recovery in physically active males.

Purpose: Ischemic preconditioning enhances exercise performance. We tested the hypothesis that ischemic preconditioning would improve intermittent exercise in the form of a repeated sprint test during cycling ergometry. Methods: In a single-blind, crossover study, fourteen recreationally-active males (mean ± SD; age 22.9 ± 3.7 years, height 1.80 ± 0.07 m, mass 77.3 ± 9.2 kg) performed twelve 6 s sprints following four 5 min periods of bilateral limb occlusion at 220 mmHg (ischemic preconditioning) or 20 mmHg (placebo). Results: Ischemic preconditioning resulted in a 2.4 ± 2.2, 2.6 ± 2.7 and 3.7 ± 2.4% substantial increase in peak power for sprints 1, 2 and 3 respectively, relative to placebo, with no further changes between trials observed for any other sprint. Similar findings were observed in the first three sprints for mean power output following ischemic preconditioning (2.8 ± 2.5, 2.6 ± 2.5 and 3.4 ± 2.1%, for sprints 1, 2 and 3 respectively), relative to placebo. Fatigue index was not substantially different between trials. At rest tissue saturation index was not different between trials. During the ischemic preconditioning / placebo stimulus there was a -19.7 ± 3.6% decrease in tissue saturation index in the ischemic preconditioning trial, relative to placebo. During exercise there was a 5.4 ± 4.8% greater maintenance of tissue saturation index in the ischemic preconditioning trial, relative to placebo. There were no substantial differences between trials for blood lactate, electromyography (EMG) median frequency, oxygen uptake or rating of perceived exertion (RPE) at any time points. Conclusion: Ischemic preconditioning improved peak and mean power output during the early stages of repeated sprint cycling and may be beneficial for sprint sports.\ud Key Words: Ischemia, occlusion, power output, multiple sprint, fatigue

The aim of this study was to examine the acute supplementation effects of dietary nitrate, caffeine, and their combination on 20-km cycling time trial performance. Using a randomized, counterbalanced, double-blind Latin-square design, 14 competitive female cyclists (age: 31 ± 7 years; height: 1.69 ± 0.07 m; body mass: 61.6 ± 6.0 kg) completed four 20-km time trials on a racing bicycle fitted to a turbo trainer. Approximately 2.5 hours before each trial, subjects consumed a 70-ml dose of concentrated beetroot juice containing either 0.45 g of dietary nitrate or with the nitrate content removed (placebo). One hour before each trial, subjects consumed a capsule containing either 5 mg·kg of caffeine or maltodextrin (placebo). There was a significant effect of supplementation on power output (p = 0.001), with post hoc tests revealing higher power outputs in caffeine (205 ± 21 W) vs. nitrate (194 ± 22 W) and placebo (194 ± 25 W) trials only. Caffeine-induced improvements in power output corresponded with significantly higher measures of heart rate (caffeine: 166 ± 12 b·min vs. placebo: 159 ± 15 b·min; p = 0.02), blood lactate (caffeine: 6.54 ± 2.40 mmol·L vs. placebo: 4.50 ± 2.11 mmol·L; p0.001), and respiratory exchange ratio (caffeine: 0.95 ± 0.04 vs. placebo: 0.91 ± 0.05; p = 0.03). There were no effects (p ≥ 0.05) of supplementation on cycling cadence, rating of perceived exertion, (Equation is included in full-text article.), or integrated electromyographic activity. The results of this study support the well-established beneficial effects of caffeine supplementation on endurance performance. In contrast, acute supplementation with dietary nitrate seems to have no effect on endurance performance and adds nothing to the benefits afforded by caffeine supplementation.

The aims of this study were to evaluate the effects of caffeine supplementation on sprint cycling performance and to determine if there was a dose-response effect. Using a randomized, double-blind, placebo-controlled design, 17 well-trained men (age: 24 ± 6 years, height: 1.82 ± 0.06 m, and body mass(bm): 82.2 ± 6.9 kg) completed 7 maximal 10-second sprint trials on an electromagnetically braked cycle ergometer. Apart from trial 1 (familiarization), all the trials involved subjects ingesting a gelatine capsule containing either caffeine or placebo (maltodextrin) 1 hour before each sprint. To examine dose-response effects, caffeine doses of 2, 4, 6, 8, and 10 mg·kg bm(-1) were used. There were no significant (p ≥ 0.05) differences in baseline measures of plasma caffeine concentration before each trial (grand mean: 0.14 ± 0.28 μg·ml(-1)). There was, however, a significant supplement × time interaction (p0.001), with larger caffeine doses producing higher postsupplementation plasma caffeine levels. In comparison with placebo, caffeine had no significant effect on peak power (p = 0.11), mean power (p = 0.55), or time to peak power (p = 0.17). There was also no significant effect of supplementation on pretrial blood lactate (p = 0.58), but there was a significant time effect (p = 0.001), with blood lactate reducing over the 50 minute postsupplementation rest period from 1.29 ± 0.36 to 1.06 ± 0.33 mmol·L(-1). The results of this study show that caffeine supplementation has no effect on short-duration sprint cycling performance, irrespective of the dosage used.

The response of calf-muscle strength, resting blood flow, and postocclusive blood flow (PObf) were investigated after 4 wk of low-load resistance training (LLRT) with and without blood-flow restriction in a matched-leg design. Ten untrained older individuals age 62–73 yr performed unilateral plantar-flexion LLRT at 25% 1-repetition maximum (1RM). One limb was trained with normal blood flow and the other had blood flow restricted using a pressure cuff above the knee. 1RM, isometric maximal voluntary contraction, and isokinetic strength at 0.52 rad/s increased (p< .05) more after LLRT with blood-flow restriction than with normal blood flow. Peak PObfincreased (p< .05) after LLRT with blood-flow restriction, compared with no change after LLRT with normal blood flow. These results suggest that 4 wk of LLRT with blood-flow restriction may be beneficial to older individuals to improve strength and blood-flow parameters.

In this study, we wished to determine whether the changes in metabolism observed during exercise in the cold are associated with changes in interleukin-6 (IL-6) and/or its soluble receptors. Eight healthy male participants performed 1 h of cycling exercise at 70% VO2max in a control (20 degrees C) and cold (0 degrees C) environment. Plasma concentrations of IL-6, soluble IL-6 receptor (sIL-6R), and sgp130 were measured before exercise, at 30 and 60 min of exercise, and 60 min after exercise. Substrate oxidation was estimated through measures of pulmonary gas exchange recorded between 50 and 55 min of cycling. Exercise in the cold resulted in an increase (P0.05) in carbohydrate oxidation (mean 2.58 g.min(-1), s = 0.49 at 20 degrees C vs. 2.85 g.min(-1), s = 0.58 at 0 degrees C) and a decrease (P0.05) in fat oxidation (0.55 g.min(-1), s = 0.17 at 20 degrees C vs. 0.38 g.min(-1), s = 0.16 at 0 degrees C) compared with the control trial. Interleukin-6 concentrations were elevated (P0.05) after 60 min of exercise in both the cold and control trials, with no differences between trials at any instant. Neither sIL-6R nor sgp130 was affected by exercise or the environment. The alterations in carbohydrate and fat utilization during 1 h of exercise in the cold are not paralleled by changes in plasma concentrations of IL-6 or its soluble receptors.