Chris Bishop

Lower extremity stiffness: effects on performance and injury and implications for training

ABSTRACT THIS ARTICLE REVIEWS RESEARCH TO DATE ON LOWER EXTREMITY STIFFNESS RELATIVE TO ITS EFFECTS ON PERFORMANCE AND INJURY. EVIDENCE SUGGESTS THAT AN OPTIMAL AMOUNT OF LOWER EXTREMITY STIFFNESS IS REQUIRED FOR SUCCESSFUL ATHLETIC PERFORMANCE, AS TOO MUCH OR TOO LITTLE CAN BE DETRIMENTAL AND POSSIBLY INJURY INDUCING. METHODS OF MEASURING LOWER EXTREMITY STIFFNESS AND FAST STRETCH-SHORTENING CYCLE PERFORMANCE ARE SUGGESTED. IN TERMS OF TRAINING, IT IS RECOMMENDED THAT A COMBINATION OF STRENGTH AND PLYOMETRIC TRAINING BE PERFORMED, AS WELL AS CORRECT EXECUTION OF LANDING MECHANICS TO IMPROVE INTERMUSCULAR COORDINATION AND TO AVOID INJURY-PROVOKING DOMINANT AGONIST-TO-ANTAGONIST COACTIVATION RATIOS.

Data analysis for strength and conditioning coaches: using Excel to analyze reliability, differences, and relationships

ABSTRACT STATISTICAL ANALYSIS IS CRUCIAL TO THE ROLE OF STRENGTH AND CONDITIONING, AND COACHES SHOULD BE ABLE TO IDENTIFY WHETHER THEIR DATA ARE RELIABLE AND OBJECTIVELY DETERMINE DIFFERENCES AND RELATIONSHIPS. THESE ANALYTICAL SKILLS ARE CENTRAL TO OUR ABILITY OF UNCOVERING TRENDS AND ASSOCIATIONS, MAKING PREDICTIONS AND ASSESSING THE EFFICACY OF TRAINING PROGRAMS. THIS ARTICLE REVIEWS STATISTICAL TESTS AVAILABLE THROUGH MICROSOFT EXCEL, COVERING RELIABILITY (THROUGH THE COEFFICIENT OF VARIATION), THE SMALLEST WORTHWHILE CHANGE (I.E., THE FIRST MEANINGFUL DIFFERENCE IN SCORES), EFFECT SIZES (I.E., THE MAGNITUDE OF CHANGE BETWEEN PERFORMANCE SCORES), AND RELATIONSHIPS (I.E., CORRELATIONS).

Physical characteristics underpinning lunging and change of direction speed in fencing

Abstract Turner, A, Bishop, C, Chavda, S, Edwards, M, Brazier, J, Kilduff, LP. Physical characteristics underpinning lunging and change of direction speed in fencing. J Strength Cond Res 30(8): 2235–2241, 2016—Lunge velocity (LV) and change of direction speed (CODS) are considered fundamental to success during fencing competitions; investigating the physical characteristics that underpin these is the aim of this study. Seventy fencers from the British Fencing National Academy took part and on average (±SD) were 16.83 ± 1.72 years of age, 178.13 ± 8.91 cm tall, 68.20 ± 9.64 kg in mass, and had 6.25 ± 2.23 years fencing experience. The relationship between anthropometric characteristics (height, arm span, and adductor flexibility) and measures of lower-body power (bilateral and unilateral countermovement jump height and reactive strength index) were examined in their ability to influence LV and CODS. In testing the former, fencers lunged (over a self-selected distance) to and from a force plate, where front leg impact and rear leg propulsive force were quantified; the lunging distance was divided by time to establish LV. Change of direction speed was measured over 12 m involving shuttles of between 2 and 4 m. Results revealed that LV and CODS averaged at 3.35 m·s−1 and 5.45 seconds, respectively, and in both cases, standing broad jump was the strongest predictor (r = 0.51 and −0.65, respectively) of performance. Rear leg drive and front leg impact force averaged at 14.61 N·kg−1 and 3 times body weight, respectively, with single leg jumps revealing an asymmetry favoring the front leg of 9 ± 8%. In conclusion, fencers should train lower-body power emphasizing horizontal displacement, noting that this seems to offset any advantage one would expect fencers of a taller stature to have. Also, the commonly reported asymmetry between legs is apparent from adolescence and thus also requires some attention.

Asymmetries of the Lower Limb: The Calculation Conundrum in Strength Training and Conditioning

ABSTRACT ASYMMETRY DETECTION HAS BEEN A TOPIC OF INTEREST IN THE STRENGTH AND CONDITIONING (SC) LITERATURE WITH NUMEROUS STUDIES PROPOSING MANY DIFFERENT EQUATIONS FOR CALCULATING BETWEEN-LIMB DIFFERENCES. HOWEVER, THERE DOES NOT SEEM TO BE A CLEAR DELINEATION AS TO WHICH EQUATION SHOULD BE USED WHEN QUANTIFYING ASYMMETRIES. CONSEQUENTLY, THE AUTHORS HAVE UNCOVERED 9 DIFFERENT EQUATIONS THAT POSE CONFUSION AS TO WHICH METHOD THE SC SPECIALIST SHOULD USE DURING DATA INTERPRETATION. THE AIM OF THIS ARTICLE IS TO IDENTIFY THE DIFFERENT EQUATIONS CURRENTLY BEING USED TO CALCULATE ASYMMETRIES AND OFFER PRACTITIONERS A GUIDE AS TO WHICH METHOD MAY BE MOST APPROPRIATE WHEN MEASURING ASYMMETRIES.

Determinants of Club Head Speed in PGA Professional Golfers.

Abstract Turner, AN. Determinants of club head speed in PGA professional golfers. J Strength Cond Res 30(8): 2266–2270, 2016—Club head speed (CHS) has been significantly correlated with golf performance, but only in amateurs. The purpose of this study therefore, was to investigate the relationship between field-based measures of strength and power with CHS in Professional Golfers Association (PGA) professional golfers, and further determine differences between age groups. A correlation design was used to test relationships between squat jump (SJ), seated medicine ball throw (SMBT), rotational medicine ball throw (RMBT), and CHS. Twenty participants volunteered to take part in the study (age, 31.95 ± 8.7 years; height, 182.75 ± 6.88 cm; mass, 90.47 ± 15.6 kg). Intraclass correlation coefficients reported high reliability for performance variables (r = 0.85–0.95). Significant correlations (p < 0.01) were found between CHS and SJ (r = 0.817) and SMBT (r = 0.706), but not RMBT (r = 0.572). A stepwise linear regression analysis identified that SJ and SMBT explained 74% of the variance in CHS. When dividing the sample based on age, professionals <30 years (n = 10; 25.6 ± 2.9 years) displayed significantly (p ⩽ 0.05) higher CHS and SJ height compared with professionals >30 (n = 10; 39.7 ± 5.5 years). Correlations to CHS for <30 were significant for SJ (r = 0.801) and SMBT (r = 0.643), but nonsignificant for RMBT. Those >30 had significant correlations to CHS not only in SMBT (r = 0.881) and SJ (r = 0.729), but also in RMBT (r = 0.642). The results of this study suggest that SJ and SMBT have the largest contribution to CHS in PGA professional golfers. When comparing age groups, it appears that younger golfers (<30 years) utilize more leg strength whereas older golfers (>30 years) utilize more upper body strength. Results suggest that strength-based leg exercises and power-based chest exercises may improve CHS in professional golfers.

A needs analysis and field-based testing battery for basketball

ABSTRACT BASKETBALL IS A HIGH-INTENSITY SPORT REQUIRING A RANGE OF ATHLETIC ABILITIES: EXPLOSIVE STRENGTH AND RATE OF FORCE DEVELOPMENT, AGILITY, COORDINATION, SPEED, ANAEROBIC LACTATE, AND ALACTIC CAPACITIES. WITHIN ELITE BASKETBALL STRENGTH AND CONDITIONING PROGRAMS, DISTINCT VARIATION IN THE ASSESSMENT OF SUCH QUALITIES IS EVIDENT, HIGHLIGHTING THE NEED FOR EVIDENCE-BASED PRACTICE TO DETERMINE ACCEPTABLE VALIDITY AND RELIABILITY OF THE MEASURES USED. THEREFORE, THE PURPOSE OF THIS REVIEW IS TO DETERMINE THE PHYSIOLOGICAL REQUIREMENTS OF THE SPORT, SO THAT SUITABLE TESTING APPROACHES CAN BE IDENTIFIED FROM WHICH COACHES CAN OPTIMALLY ASSESS THE PHYSICAL CAPABILITIES OF THEIR ATHLETES.

Holistic hamstring health: not just the Nordic hamstring exercise

Hamstring strain injuries (HSIs) are the most prevalent in team sports, accounting for 12%–26% of injuries in Australian rules football, American football, football, rugby and track and field.1 The biceps femoris is the most commonly injured muscle with 53%–68% of injuries occurring during sprinting.1 In European football, the incidence and recurrence of HSI has continued to rise, while in Australian rules football, a notable reduction in HSI recurrences has been reported.1 It is possible that evidence-based hamstring injury prevention is not adopted or adhered to in some elite level football teams,2 which may explain the rise in HSI. Although not an exhaustive list, HSI risk factors include: age, previous injury, strength imbalance, flexibility, fatigue1 and low eccentric strength.3 There is a growing body of evidence on the Nordic hamstring exercise (NHE) and its impact on HSI reduction.4 However, there may be misconceptions (fuelled by social media) that this is the only exercise used …

Do fencers require a weapon-specific approach to strength and conditioning training?

Abstract Turner, AN, Bishop, CJ, Cree, JA, Edwards, ML, Chavda, S, Read, PJ, and Kirby, DMJ. Do fencers require a weapon-specific approach to strength and conditioning training? J Strength Cond Res 31(6): 1662–1668, 2017—There are 3 types of weapons used in Olympic fencing: the épée, foil, and sabre. The aim of this study was to determine if fencers exhibited different physical characteristics across weapons. Seventy-nine male (n = 46) and female (n = 33) national standard fencers took part in this study. Fencers from each weapon (male and female), i.e., épée (n = 19 and 10), foil (n = 22 and 14), and sabre (n = 13 and 10), were (mean ± SD) 15.9 ± 0.7 years of age, 178.5 ± 7.9 cm tall, 67.4 ± 12.2 kg in mass and had 6.3 ± 2.3 years fencing experience; all were in regular training (∼4 times per week). Results revealed that across all performance tests (lower-body power, reactive strength index, change of direction speed, and repeat lunge ability), there was no significant main effect for weapon in male fencers (p = 0.63) or female fencers (p = 0.232), but a significant main affect for gender (p < 0.001). Pairwise comparisons revealed that male fencers scored better during the countermovement jump, change of direction speed, and repeat lunge ability test (p < 0.001). The former findings may be because of similarities in bout intensity and time, movement types (lunging and changing direction), and the need to execute competition actions as explosively as possible. Based on the findings of the present study, it could be indicated that épée, foil, and sabre fencers do not require a weapon-specific approach to strength and conditioning training. Each fencer should target the area they are weakest at, rather than an area that they feel best represents the unique demands of their weapon.

Using the split squat to potentiate bilateral and unilateral jump performance

Abstract Bishop, CJ, Tarrant, J, Jarvis, PT, and Turner, AN. Using the split squat to potentiate bilateral and unilateral jump performance. J Strength Cond Res 31(8): 2216–2222, 2017—The purpose of this study was to examine if a split squat conditioning exercise with no or light loads could potentiate unilateral and bilateral jump performance. Twelve semiprofessional rugby players (age: 22.3 ± 1.4 years; height: 1.84 ± 0.05 m, mass: 92.4 ± 9.6 kg) from the English National League 1 performed a series of unilateral and bilateral countermovement jumps (CMJ) and broad jumps (BJ) over the course of 2 testing days. Both testing days involved performing baseline jumps before completing 2 sets of 10 repetitions of a split squat, this completed with either bodyweight (testing session 1) or a 30 kg weighted vest (testing session 2). A 5-minute recovery period was permitted both after the warm-up and the completion of the split squat exercise. Significantly larger bilateral jump scores were reported after completion of the bodyweight split squat: CMJ (p = 0.001, ES = 0.44, [mean difference 2.517]), BJ (p = 0.001, ES = 0.37, [mean difference 3.817]), and the weighted vest split squat; CMJ (p = 0.001, ES = 0.8, [mean difference 4.383]), BJ (p = 0.001, ES = 0.68, [mean difference 6.817]). The findings of this study demonstrate that no or light loads of a split squat conditioning exercise are able to potentiate bilateral jump performance in semiprofessional rugby players without the need for expensive weight room equipment. As such, this may provide coaches with a viable option of enhancing bilateral jump performance as part of a warm-up or on-field conditioning practice.

Effects of inter-limb asymmetries on physical and sports performance: a systematic review

ABSTRACT The prevalence of inter-limb asymmetries has been reported in numerous studies across a wide range of sports and physical qualities; however, few have analysed their effects on physical and sports performance. A systematic review of the literature was undertaken using the Medline and SPORT Discus databases, with all articles required to meet a specified criteria based on a quality review. Eighteen articles met the inclusion criteria, relating participant asymmetry scores to physical and sports performance measures. The findings of this systematic review indicate that inter-limb differences in strength may be detrimental to jumping, kicking and cycling performance. When inter-limb asymmetries are quantified during jumping based exercises, they have been primarily used to examine their association with change of direction speed with mixed findings. Inter-limb asymmetries have also been quantified in anthropometry, sprinting, dynamic balance and sport-specific actions, again with inconsistent findings. However, all results have been reported using associative analysis with physical or sport performance metrics with no randomised controlled trials included. Further research is warranted to understand the mechanisms that underpin inter-limb differences and the magnitude of performance changes that can be accounted for by these asymmetries.