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Sparkes W, Turner AN, Weston M, Russell M, Johnston MJ, Kilduff LP. The effect of training order on neuromuscular, endocrine and mood response to small-sided games and resistance training sessions over a 24-h period. J Sci Med Sport 2020; 23:866-871. [PMID: 32061525 DOI: 10.1016/j.jsams.2020.01.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 01/23/2020] [Accepted: 01/31/2020] [Indexed: 10/25/2022]
Abstract
OBJECTIVES This study examined the acute effect of small-sided-game (SSG) and resistance training sequence on neuromuscular, endocrine and mood response over a 24-h (h) period. DESIGN Repeated measures. METHODS Fourteen semi-professional soccer players performed SSG-training (4vs4+goalkeepers; 6×7-min, 2-min inter-set recovery) followed by resistance training 2h later (back-squat, Romanian deadlift, barbell-hip-thrust; 4×4 repetitions, 4-min inter-set recovery; 85% 1 rep-max) (SSG+RES), and on a separate week reversed the session order (RES+SSG). Physical demands of SSG's were monitored using global positioning systems (GPS) and ratings of perceived exertion (RPE). Countermovement-jump (CMJ; peak power output; jump height) and brief assessment of mood were collected before (pre), during (0h) and after (+24h) both protocols. Salivary testosterone and cortisol concentrations were obtained at the same time-points but with the inclusion of a measure immediately prior to the second training session (+2h). RESULTS GPS outputs and RPE were similar between SSG-training during both protocols. Between-protocol comparisons revealed no significant differences at +24h in CMJ performance, mood, and endocrine markers. Testosterone was higher at 0h during RES+SSG in comparison to SSG+RES (moderate-effect; +21.4±26.7pgml-1; p=0.010), yet was similar between protocols by +2h. CONCLUSIONS The order of SSG and resistance training does not appear to influence the physical demands of SSG's with sufficient recovery between two sessions performed on the same day. Session order did not influence neuromuscular, endocrine or mood responses at +24h, however a favourable testosterone response from the resistance first session may enhance neuromuscular performance in the second session of the day.
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Affiliation(s)
- W Sparkes
- Applied Sports Technology Exercise and Medicine Research Centre (A-STEM), Health and Sport Portfolio, Swansea University, UK
| | - A N Turner
- London Sports Institute, Science and Technology, Middlesex University, UK
| | - M Weston
- Department of Psychology, Sport and Exercise, School of Social Sciences, Humanities and Law, Teesside University, UK
| | - M Russell
- School of Social and Health Sciences, Leeds Trinity University, UK
| | - M J Johnston
- British Athletics, University of Loughborough, UK
| | - L P Kilduff
- Applied Sports Technology Exercise and Medicine Research Centre (A-STEM), Health and Sport Portfolio, Swansea University, UK.
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Sparkes W, Turner AN, Cook CJ, Weston M, Russell M, Johnston MJ, Kilduff LP. The neuromuscular, endocrine and mood responses to a single versus double training session day in soccer players. J Sci Med Sport 2019; 23:69-74. [PMID: 31526664 DOI: 10.1016/j.jsams.2019.08.291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 05/17/2019] [Accepted: 08/29/2019] [Indexed: 10/26/2022]
Abstract
OBJECTIVES This study profiled the 24h neuromuscular, endocrine and mood responses to a single versus a double training day in soccer players. DESIGN Repeated measures. METHODS Twelve semi-professional soccer players performed small-sided-games (SSG's; 4 vs 4+goalkeepers; 6×7-min, 2-min inter-set recovery) with neuromuscular (peak-power output, PPO; jump height, JH), endocrine (salivary testosterone, cortisol), and mood measures collected before (pre) and after (0h, +24h). The following week, the same SSG protocol was performed with an additional lower body strength training session (back-squat, Romanian deadlift, barbell hip thrust; 4×4 repetitions, 4-min inter-set recovery; 85% 1 rep-max) added at 2h after the SSG's. RESULTS Between-trial comparisons revealed possible to likely small impairments in PPO (2.5±2.2Wkg-1; 90% Confidence Limits: ±2.2Wkg-1), JH (-1.3; ±2.0cm) and mood (4.6; ±6.1AU) in response to the double versus single sessions at +24h. Likely to very likely small favourable responses occurred following the single session for testosterone (-15.2; ±6.1pgml-1), cortisol (0.072; ±0.034ugdl-1) and testosterone/cortisol ratio (-96.6; ±36.7AU) at +24h compared to the double session trial. CONCLUSIONS These data highlight that performance of two training sessions within a day resulted in possible to very likely small impairments of neuromuscular performance, mood score and endocrine markers at +24h relative to a single training session day. A strategy of alternating high intensity explosive training days containing multiple sessions with days emphasising submaximal technical/tactical activities may be beneficial for those responsible for the design and delivery of soccer training programs.
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Affiliation(s)
- W Sparkes
- Applied Sports Technology Exercise and Medicine Research Centre (A-STEM), Health and Sport Portfolio, Swansea University, UK
| | - A N Turner
- London Sports Institute, Science and Technology, Middlesex University, UK
| | - C J Cook
- Applied Sports Technology Exercise and Medicine Research Centre (A-STEM), Health and Sport Portfolio, Swansea University, UK
| | - M Weston
- Department of Psychology, Sport and Exercise, School of Social Sciences, Humanities and Law, Teesside University, UK
| | - M Russell
- School of Social and Health Sciences, Leeds Trinity University, UK
| | - M J Johnston
- British Athletics, University of Loughborough, UK
| | - L P Kilduff
- Applied Sports Technology Exercise and Medicine Research Centre (A-STEM), Health and Sport Portfolio, Swansea University, UK.
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Cook CJ, Kilduff LP, Crewther BT. Basal and stress-induced salivary testosterone variation across the menstrual cycle and linkage to motivation and muscle power. Scand J Med Sci Sports 2018; 28:1345-1353. [DOI: 10.1111/sms.13041] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2017] [Indexed: 12/17/2022]
Affiliation(s)
- C. J. Cook
- Research Institute for Sport and Exercise; University of Canberra; Canberra Australia
- School of Sport, Health and Exercise Sciences; Bangor University; Bangor UK
- Hamlyn Centre; Imperial College; London UK
| | - L. P. Kilduff
- A-STEM; School of Engineering; Swansea University; Swansea UK
- Welsh Institute of Performance Science (WIPS); Swansea University; Swansea UK
| | - B. T. Crewther
- Hamlyn Centre; Imperial College; London UK
- Institute of Sport - National Research Institute; Warsaw Poland
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Heffernan SM, Stebbings GK, Kilduff LP, Erskine RM, Day SH, Morse CI, McPhee JS, Cook CJ, Vance B, Ribbans WJ, Raleigh SM, Roberts C, Bennett MA, Wang G, Collins M, Pitsiladis YP, Williams AG. Fat mass and obesity associated (FTO) gene influences skeletal muscle phenotypes in non-resistance trained males and elite rugby playing position. BMC Genet 2017; 18:4. [PMID: 28103813 PMCID: PMC5248469 DOI: 10.1186/s12863-017-0470-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 01/10/2017] [Indexed: 11/25/2022] Open
Abstract
Background FTO gene variants have been associated with obesity phenotypes in sedentary and obese populations, but rarely with skeletal muscle and elite athlete phenotypes. Methods In 1089 participants, comprising 530 elite rugby athletes and 559 non-athletes, DNA was collected and genotyped for the FTO rs9939609 variant using real-time PCR. In a subgroup of non-resistance trained individuals (NT; n = 120), we also assessed structural and functional skeletal muscle phenotypes using dual energy x-ray absorptiometry, ultrasound and isokinetic dynamometry. In a subgroup of rugby athletes (n = 77), we assessed muscle power during a countermovement jump. Results In NT, TT genotype and T allele carriers had greater total body (4.8% and 4.1%) and total appendicular lean mass (LM; 3.0% and 2.1%) compared to AA genotype, with greater arm LM (0.8%) in T allele carriers and leg LM (2.1%) for TT, compared to AA genotype. Furthermore, the T allele was more common (94%) in selected elite rugby union athletes (back three and centre players) who are most reliant on LM rather than total body mass for success, compared to other rugby athletes (82%; P = 0.01, OR = 3.34) and controls (84%; P = 0.03, OR = 2.88). Accordingly, these athletes had greater peak power relative to body mass than other rugby athletes (14%; P = 2 x 10-6). Conclusion Collectively, these results suggest that the T allele is associated with increased LM and elite athletic success. This has implications for athletic populations, as well as conditions characterised by low LM such as sarcopenia and cachexia.
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Affiliation(s)
- S M Heffernan
- MMU Sports Genomics Laboratory, Manchester Metropolitan University, Crewe Green Road, Crewe, CW1 5DU, UK.
| | - G K Stebbings
- MMU Sports Genomics Laboratory, Manchester Metropolitan University, Crewe Green Road, Crewe, CW1 5DU, UK
| | - L P Kilduff
- A-STEM, College of Engineering, Swansea University, Swansea, UK
| | - R M Erskine
- Research Institute for Sport & Exercise Sciences, Liverpool John Moores University, Liverpool, UK.,Institute of Sport, Exercise and Health, University College London, London, UK
| | - S H Day
- MMU Sports Genomics Laboratory, Manchester Metropolitan University, Crewe Green Road, Crewe, CW1 5DU, UK
| | - C I Morse
- MMU Sports Genomics Laboratory, Manchester Metropolitan University, Crewe Green Road, Crewe, CW1 5DU, UK
| | - J S McPhee
- School of Healthcare Science, Manchester Metropolitan University, Manchester, UK
| | - C J Cook
- A-STEM, College of Engineering, Swansea University, Swansea, UK.,School of Sport, Health and Exercise Sciences, Bangor University, Bangor, UK
| | - B Vance
- Institute of Cardiovascular & Medical Sciences University of Glasgow, Glasgow, UK
| | - W J Ribbans
- Centre for Physical Activity and Chronic Disease, Institute of Health and Wellbeing, University of Northampton, Northampton, UK
| | - S M Raleigh
- Centre for Physical Activity and Chronic Disease, Institute of Health and Wellbeing, University of Northampton, Northampton, UK
| | - C Roberts
- Medical and Scientific Department, South African Rugby Union, Cape Town, South Africa.,Discipline of Sports Science, Faculty of Health Sciences, University of Kwazulu-Natal, Durban, South Africa
| | - M A Bennett
- A-STEM, College of Engineering, Swansea University, Swansea, UK
| | - G Wang
- FIMS Reference Collaborating Centre of Sports Medicine for Anti-Doping Research, University of Brighton, Brighton, UK
| | - M Collins
- Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town (UCT), Cape Town, South Africa
| | - Y P Pitsiladis
- FIMS Reference Collaborating Centre of Sports Medicine for Anti-Doping Research, University of Brighton, Brighton, UK
| | - A G Williams
- MMU Sports Genomics Laboratory, Manchester Metropolitan University, Crewe Green Road, Crewe, CW1 5DU, UK.,Institute of Sport, Exercise and Health, University College London, London, UK
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Crewther BT, Carruthers J, Kilduff LP, Sanctuary CE, Cook CJ. Temporal associations between individual changes in hormones, training motivation and physical performance in elite and non-elite trained men. Biol Sport 2016; 33:215-21. [PMID: 27601775 PMCID: PMC4993136 DOI: 10.5604/20831862.1201810] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 12/23/2015] [Accepted: 01/09/2016] [Indexed: 01/11/2023] Open
Abstract
To advance our understanding of the hormonal contribution to athletic performance, we examined the temporal associations between individual changes in testosterone (T) and/or cortisol (C) concentrations, training motivation and physical performance in elite and non-elite trained men. Two male cohorts classified as elites (n = 12) and non-elites (n = 12) completed five testing sessions over a six-week period. The athletes were tested for salivary T, C, T/C ratio, self-perceived training motivation, countermovement jump (CMJ) height and isometric mid-thigh pull peak force (IMTP PF), after which an actual training workout was performed. The elite men reported higher motivation to train and they produced greater CMJ height overall, whereas the non-elites had higher pooled T levels (p < 0.05). No significant group differences in C concentrations, T/C ratio or IMTP PF were found. The individual changes in T levels were positively associated with training motivation in the elite men only (p = 0.033), but the hormonal and motivation measures did not predict CMJ height or IMTP PF in either group. The monitoring of elite and non-elite men across a short training block revealed differences in T levels, motivation and lower-body power, which may reflect training and competitive factors in each group. Despite having lower T levels, the elite athletes showed better linkage between pre-training T fluctuations and subsequent motivation to train. The nature of the performance tests (i.e. single repetition trials) could partly explain the lack of an association with the hormonal and motivational measures.
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Affiliation(s)
- B T Crewther
- Institute of Sport - National Research Institute, Warsaw, Poland; Hamlyn Centre, Imperial College, London, UK
| | - J Carruthers
- Al-Attar Physical Medicine, Rehabilitation and Sports Medicine Center, Doha, Qatar
| | - L P Kilduff
- Applied Sports, Technology, Exercise and Medicine, College of Engineering, Swansea University, Swansea, UK; Welsh Institute of Performance Science, Swansea University, Swansea, UK
| | - C E Sanctuary
- Newcastle Knights Rugby League, Newcastle, Australia
| | - C J Cook
- Hamlyn Centre, Imperial College, London, UK; School of Sport, Health and Exercise Science, Bangor University, Bangor, UK; Welsh Institute of Performance Science, Swansea University, Swansea, UK
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Turner D, Luzio S, Gray BJ, Bain SC, Hanley S, Richards A, Rhydderch DC, Martin R, Campbell MD, Kilduff LP, West DJ, Bracken RM. Algorithm that delivers an individualized rapid-acting insulin dose after morning resistance exercise counters post-exercise hyperglycaemia in people with Type 1 diabetes. Diabet Med 2016. [PMID: 26220149 DOI: 10.1111/dme.12870] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS To develop an algorithm that delivers an individualized dose of rapid-acting insulin after morning resistance exercise to counter post-exercise hyperglycaemia in individuals with Type 1 diabetes. METHODS Eight people with Type 1 diabetes, aged 34 ± 7 years with HbA1c concentrations 72 ± 12 mmol/mol (8.7 ± 1.1%), attended our laboratory on two separate mornings after fasting, having taken their usual basal insulin the previous evening. These people performed a resistance exercise session comprising six exercises for two sets of 10 repetitions at 60% of the maximum amount of force that was generated in one maximal contraction (60% 1RM). In a randomized and counterbalanced order, the participants were administered an individualized dose of rapid-acting insulin (2 ± 1 units, range 0-4 units) immediately after resistance exercise (insulin session) by means of an algorithm or were not administered this (no-insulin session). Venous blood glucose concentrations were measured for 125 min after resistance exercise. Data (mean ± sem values) were analysed using anova (P ≤ 0.05). RESULTS Participants had immediate post-resistance exercise hyperglycaemia (insulin session 13.0 ± 1.6 vs. no-insulin session 12.7 ± 1.5 mmol/l; P = 0.834). The decline in blood glucose concentration between peak and 125 min after exercise was greater in the insulin exercise session than in the no-insulin session (3.3 ± 1.0 vs. 1.3 ± 0.4 mmol/l: P = 0.015). There were no episodes of hypoglycaemia (blood glucose <3.9 mmol/l). CONCLUSIONS Administration of rapid-acting insulin according to an individualized algorithm reduced the hyperglycaemia associated with morning resistance exercise without causing hypoglycaemia in the 2 h post-exercise period in people with Type 1 diabetes.
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Affiliation(s)
- D Turner
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering, Swansea University, Singleton Park, Swansea, UK
- Diabetes Research Group, College of Medicine, Swansea University, Singleton Park, Swansea, UK
| | - S Luzio
- Diabetes Research Group, College of Medicine, Swansea University, Singleton Park, Swansea, UK
- Abertawe Bro Morgannwg University Health Board, Singleton Hospital, Swansea, UK
| | - B J Gray
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering, Swansea University, Singleton Park, Swansea, UK
- Diabetes Research Group, College of Medicine, Swansea University, Singleton Park, Swansea, UK
| | - S C Bain
- Diabetes Research Group, College of Medicine, Swansea University, Singleton Park, Swansea, UK
- Abertawe Bro Morgannwg University Health Board, Singleton Hospital, Swansea, UK
| | - S Hanley
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering, Swansea University, Singleton Park, Swansea, UK
| | - A Richards
- Abertawe Bro Morgannwg University Health Board, Singleton Hospital, Swansea, UK
| | - D C Rhydderch
- Abertawe Bro Morgannwg University Health Board, Singleton Hospital, Swansea, UK
| | - R Martin
- Cwm Taf University Health Board, Merthyr Tydfil, UK
| | - M D Campbell
- Department of Sport, Exercise and Rehabilitation, Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, UK
| | - L P Kilduff
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering, Swansea University, Singleton Park, Swansea, UK
| | - D J West
- Department of Sport, Exercise and Rehabilitation, Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, UK
| | - R M Bracken
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering, Swansea University, Singleton Park, Swansea, UK
- Diabetes Research Group, College of Medicine, Swansea University, Singleton Park, Swansea, UK
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Heffernan SM, Kilduff LP, Erskine RM, Day SH, McPhee JS, McMahon GE, Stebbings GK, Neale JPH, Lockey SJ, Ribbans WJ, Cook CJ, Vance B, Raleigh SM, Roberts C, Bennett MA, Wang G, Collins M, Pitsiladis YP, Williams AG. Association of ACTN3 R577X but not ACE I/D gene variants with elite rugby union player status and playing position. Physiol Genomics 2016; 48:196-201. [PMID: 26757799 PMCID: PMC4929273 DOI: 10.1152/physiolgenomics.00107.2015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/07/2016] [Indexed: 12/30/2022] Open
Abstract
We aimed to quantify the ACE I/D and ACTN3 R577X (rs1815739) genetic variants in elite rugby athletes (rugby union and league) and compare genotype frequencies to controls and between playing positions. The rugby athlete cohort consisted of 507 Caucasian men, including 431 rugby union athletes that for some analyses were divided into backs and forwards and into specific positional groups: front five, back row, half backs, centers, and back three. Controls were 710 Caucasian men and women. Real-time PCR of genomic DNA was used to determine genotypes using TaqMan probes and groups were compared using χ2 and odds ratio (OR) statistics. Correction of P values for multiple comparisons was according to Benjamini-Hochberg. There was no difference in ACE I/D genotype between groups. ACTN3 XX genotype tended to be underrepresented in rugby union backs (15.7%) compared with forwards (24.8%, P = 0.06). Interestingly, the 69 back three players (wings and full backs) in rugby union included only six XX genotype individuals (8.7%), with the R allele more common in the back three (68.8%) than controls (58.0%; χ2 = 6.672, P = 0.04; OR = 1.60) and forwards (47.5%; χ2 = 11.768, P = 0.01; OR = 2.00). Association of ACTN3 R577X with playing position in elite rugby union athletes suggests inherited fatigue resistance is more prevalent in forwards, while inherited sprint ability is more prevalent in backs, especially wings and full backs. These results also demonstrate the advantage of focusing genetic studies on a large cohort within a single sport, especially when intrasport positional differences exist, instead of combining several sports with varied demands and athlete characteristics.
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Affiliation(s)
- S M Heffernan
- MMU Sports Genomics Laboratory, Manchester Metropolitan University, Crewe, United Kingdom;
| | - L P Kilduff
- A-STEM, College of Engineering, Swansea University, Swansea, United Kingdom
| | - R M Erskine
- Research Institute for Sport & Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom; Institute of Sport, Exercise and Health, University College London, London, United Kingdom
| | - S H Day
- MMU Sports Genomics Laboratory, Manchester Metropolitan University, Crewe, United Kingdom
| | - J S McPhee
- School of Healthcare Science, Manchester Metropolitan University, Manchester, United Kingdom
| | - G E McMahon
- MMU Sports Genomics Laboratory, Manchester Metropolitan University, Crewe, United Kingdom; Northern Ireland Sports Institute, Newtownabbey, Belfast, United Kingdom
| | - G K Stebbings
- MMU Sports Genomics Laboratory, Manchester Metropolitan University, Crewe, United Kingdom
| | - J P H Neale
- MMU Sports Genomics Laboratory, Manchester Metropolitan University, Crewe, United Kingdom
| | - S J Lockey
- MMU Sports Genomics Laboratory, Manchester Metropolitan University, Crewe, United Kingdom
| | - W J Ribbans
- Division of Sport, Exercise and Life Science, University of Northampton, Northampton, United Kingdom
| | - C J Cook
- School of Sport, Health and Exercise Sciences, Bangor University, Bangor, United Kingdom
| | - B Vance
- Institute of Cardiovascular & Medical Sciences University of Glasgow, Glasgow, United Kingdom
| | - S M Raleigh
- Division of Sport, Exercise and Life Science, University of Northampton, Northampton, United Kingdom
| | - C Roberts
- Medical and Scientific Department, South African Rugby Union, Cape Town, South Africa; Discipline of Sports Science, Faculty of Health Sciences, University of Kwazulu-Natal, Durban, South Africa
| | - M A Bennett
- A-STEM, College of Engineering, Swansea University, Swansea, United Kingdom
| | - G Wang
- Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Brighton, United Kingdom; and
| | - M Collins
- MRC/UCT Research Unit for Exercise Science and Sports Medicine, University of Cape Town (UCT), Cape Town, South Africa
| | - Y P Pitsiladis
- Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Brighton, United Kingdom; and
| | - A G Williams
- MMU Sports Genomics Laboratory, Manchester Metropolitan University, Crewe, United Kingdom; Institute of Sport, Exercise and Health, University College London, London, United Kingdom
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Russell M, Sparkes W, Northeast J, Cook CJ, Bracken RM, Kilduff LP. Relationships between match activities and peak power output and Creatine Kinase responses to professional reserve team soccer match-play. Hum Mov Sci 2015; 45:96-101. [PMID: 26615476 DOI: 10.1016/j.humov.2015.11.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 11/16/2015] [Accepted: 11/19/2015] [Indexed: 10/22/2022]
Abstract
The specific movement demands of soccer that are linked to post-match recovery and readiness to train are unclear. Therefore, we examined the relationship between Global Positioning System (GPS) variables and the change (Δ; from baseline) in Creatine Kinase (CK) concentrations and peak power output (PPO; during the countermovement jump) at 24h and 48h post-match. Fifteen English Premier League reserve team players were examined over 1-4 matches. Measurements of CK and PPO were taken before (24h prior to match-play) and after (+24h and +48h) each game during which movement demands were quantified using 10Hz GPS data. High intensity distance covered (r=0.386, p=0.029; r=-0.349; p=0.050), high intensity distance covered⋅min(-1) (r=0.365, p=0.040; r=-0.364, p=0.040), high speed running distance (r=0.363, p=0.041; r=-0.360, p=0.043) and the number of sprints⋅min(-1) (r=0.410, p=0.020; r=-0.368, p=0.038) were significantly related to ΔCK and ΔPPO at +24h post-match, respectively. No relationships were observed between any match variables and ΔCK and ΔPPO after +48h of recovery. These findings highlight that high intensity match activities are related to ΔCK and ΔPPO in the 24h, but not 48h, following soccer match-play. Such information is likely of interest to those responsible for the design of soccer player's training schedules in the days following a match.
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Affiliation(s)
- M Russell
- Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, United Kingdom
| | - W Sparkes
- Applied Sports Technology Exercise and Medicine Research Centre (A-STEM), Swansea University, Swansea, United Kingdom; Swansea City Association Football Club, Swansea, United Kingdom
| | - J Northeast
- Applied Sports Technology Exercise and Medicine Research Centre (A-STEM), Swansea University, Swansea, United Kingdom; Swansea City Association Football Club, Swansea, United Kingdom
| | - C J Cook
- School of Sport, Health and Exercise Sciences, Bangor University, Bangor, United Kingdom
| | - R M Bracken
- Applied Sports Technology Exercise and Medicine Research Centre (A-STEM), Swansea University, Swansea, United Kingdom
| | - L P Kilduff
- Applied Sports Technology Exercise and Medicine Research Centre (A-STEM), Swansea University, Swansea, United Kingdom; Welsh Institute of Performance Sciences (WIPS), Swansea University, Swansea, United Kingdom.
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Turner D, Gray BJ, Luzio S, Dunseath G, Bain SC, Hanley S, Richards A, Rhydderch DC, Ayles M, Kilduff LP, Campbell MD, West DJ, Bracken RM. Similar magnitude of post-exercise hyperglycemia despite manipulating resistance exercise intensity in type 1 diabetes individuals. Scand J Med Sci Sports 2015; 26:404-12. [PMID: 25919405 DOI: 10.1111/sms.12472] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2015] [Indexed: 12/20/2022]
Abstract
The aim of this study was to compare the glycemic and glucoregulatory hormone responses to low- and moderate-intensity morning resistance exercise (RE) sessions in type 1 diabetes (T1DM). Following maximal strength assessments (1RM), eight T1DM (HbA1C :72 ± 12 mmol/mol, age:34 ± 7 years, body mass index:25.7 ± 1.6 kg/m(2) ) participants attended the research facility on two separate occasions, having fasted and taken their usual basal insulin but omitting rapid-acting insulin. Participants performed six exercises for two sets of 20 repetitions at 30%1RM during one session [low-intensity RE session (LOW)] and two sets of 10 repetitions at 60%1RM during another session [moderate-intensity RE session (MOD)], followed by 65-min recovery. Sessions were matched for total mass lifted (kg). Venous blood samples were taken before and after exercise. Data (mean ± SEM) were analyzed using analysis of variance (P ≤ 0.05). There were no hypoglycemic occurrences throughout the study. Blood glucose rose similarly between sessions during exercise (P = 0.382), remaining comparable between sessions throughout recovery (P > 0.05). There was no effect of RE intensity on metabolic acidosis (P > 0.05) or peak growth hormone responses (P = 0.644), but a tendency for greater catecholamine responses under LOW (individualized peak concentrations: adrenaline MOD 0.55 ± 0.13 vs LOW 1.04 ± 0.37 nmol/L, P = 0.155; noradrenaline MOD 4.59 ± 0.86 vs LOW 7.11 ± 1.82 nmol/L, P = 0.082). The magnitude of post-exercise hyperglycemia does not differ between equal volume low and moderate intensity RE sessions performed in the morning.
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Affiliation(s)
- D Turner
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering, Swansea University, Swansea, UK.,Diabetes Research Group, College of Medicine, Swansea University, Swansea, UK
| | - B J Gray
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering, Swansea University, Swansea, UK.,Diabetes Research Group, College of Medicine, Swansea University, Swansea, UK
| | - S Luzio
- Diabetes Research Group, College of Medicine, Swansea University, Swansea, UK.,Abertawe Bro Morgannwg University Health Board, Singleton Hospital, Swansea, UK
| | - G Dunseath
- Diabetes Research Group, College of Medicine, Swansea University, Swansea, UK
| | - S C Bain
- Diabetes Research Group, College of Medicine, Swansea University, Swansea, UK.,Abertawe Bro Morgannwg University Health Board, Singleton Hospital, Swansea, UK
| | - S Hanley
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering, Swansea University, Swansea, UK
| | - A Richards
- Abertawe Bro Morgannwg University Health Board, Singleton Hospital, Swansea, UK
| | - D C Rhydderch
- Abertawe Bro Morgannwg University Health Board, Singleton Hospital, Swansea, UK
| | - M Ayles
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering, Swansea University, Swansea, UK
| | - L P Kilduff
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering, Swansea University, Swansea, UK
| | - M D Campbell
- Department of Sport, Exercise and Rehabilitation, Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, UK
| | - D J West
- Department of Sport, Exercise and Rehabilitation, Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, UK
| | - R M Bracken
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering, Swansea University, Swansea, UK.,Diabetes Research Group, College of Medicine, Swansea University, Swansea, UK
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Crewther BT, Kilduff LP, Cook CJ. Trained and untrained males show reliable salivary testosterone responses to a physical stimulus, but not a psychological stimulus. J Endocrinol Invest 2014; 37:1065-72. [PMID: 25200995 DOI: 10.1007/s40618-014-0144-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Accepted: 07/26/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND The testosterone (T) responses to a physical stimulus are thought to be more stable and reproducible compared to a psychological stimulus. PURPOSE This study compared the salivary T (Sal-T) responses to both stimuli in four groups of men: professional rugby players (n = 17), recreational rugby players (n = 10), a mixed athlete group (n = 14) and untrained controls (n = 12). METHODS Each group completed three treatments: (1) watching a video with aggressive rugby footage, (2) performing a short bout of sprint exercise and (3) a control session. Saliva samples were taken before and 15 min after each treatment. RESULTS The sprint exercise changes in Sal-T levels were similar in the elite rugby (17.1 ± 11.1%), recreational rugby (11.9 ± 15.9%), mixed athlete (27.6 ± 32.0%) and control groups (25.3 ± 23.6%). In response to the video, Sal-T increased in the elite rugby (6.9 ± 6.4%) and untrained groups (11.9 ± 13.5%), but decreased in the recreational rugby players (-7.5 ± 11.0%). The individual Sal-T responses to the sprints were also correlated (r = 0.69 to 0.82) with other treatment responses. CONCLUSIONS Sprint exercise had a more consistent effect on Sal-T than a video with aggressive content and thus, could provide a reliable stimulus for increasing T availability in men with different training backgrounds. Individual Sal-T reactivity also appears to be somewhat stable across different treatments. These data provide further understanding around the induction, moderation and interpretation of T physiology.
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Affiliation(s)
- B T Crewther
- Hamlyn Centre for Robotic Surgery, Imperial College South Kensington Campus, London, SW7 2AZ, UK,
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11
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Turner D, Luzio S, Kilduff LP, Gray BJ, Dunseath G, Bain SC, Campbell MD, West DJ, Bracken RM. Reductions in resistance exercise-induced hyperglycaemic episodes are associated with circulating interleukin-6 in type 1 diabetes. Diabet Med 2014; 31:1009-13. [PMID: 24702172 DOI: 10.1111/dme.12462] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 02/05/2014] [Accepted: 04/02/2014] [Indexed: 02/01/2023]
Abstract
AIMS To determine the influence of different volumes of resistance exercise on circulating interleukin-6 (IL-6) and to explore the relationships between IL-6 and glycaemia. METHODS Eight participants with complication-free type 1 diabetes, whose mean ± SEM age was 38 (6) years, mean ± SEM HbA(1c) concentration was 71 ±11 mmol/mol (8.7 ±1.0%) and mean ± SEM type 1 diabetes duration was 15 ±13 years, attended the research facility after an overnight fast on four separate occasions, having administered their basal insulin the night before (glargine 27.5±3.1U, n=8), but omitted morning rapid-acting insulin. Participants completed either a one-set (14-min), two-set (28-min), or three-set (42-min) resistance exercise trial (eight exercises × 10 repetitions) at 67±3% one-repetition maximum followed by a 60-min recovery, or a resting control trial. Venous blood samples were taken before and after exercise. Data were analysed using repeated-measures ANOVA (P≤0.05). RESULTS Whereas IL-6 levels remained similar to baseline levels after one set of resistance exercises (30 min, P=0.287; 60 min, P=0.318), IL-6 levels were > baseline levels at 60 min post-exercise after a two-set exercise trial (2.94 ± 0.94 pg/ml, P=0.002) and doubled at both 30 min (4.01 ± 1.00 pg/ml, P=0.048) and 60 min (4.28 ± 1.25 pg/ml, P=0.084) post-exercise after the three-set resistance exercise trial. Post-exercise blood glucose area under the curve (mmol/l/60 min) was greater after both the one-set (P=0.025) and two-set trials (P=0.008), than after the control trial, but similar between the three-set trial and the control trial (P=0.240). The rise in IL-6 from baseline to peak concentration significantly correlated inversely with blood glucose area under the curve (r=-0.65, P=0.041). CONCLUSIONS Circulating IL-6 is increased by resistance exercise in a volume-dependent manner, and resistance exercise-induced increases in IL-6 correlated with reductions in post-exercise hyperglycaemia in type 1 diabetes, suggesting a role for IL-6 in improving post-resistance exercise glycaemic disturbances in type 1 diabetes.
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Affiliation(s)
- D Turner
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering, Swansea University, Singleton Park, Swansea, UK; Diabetes Research Group, College of Medicine, Swansea University, Singleton Park, Swansea, UK
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12
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Turner D, Luzio S, Gray BJ, Dunseath G, Rees ED, Kilduff LP, Campbell MD, West DJ, Bain SC, Bracken RM. Impact of single and multiple sets of resistance exercise in type 1 diabetes. Scand J Med Sci Sports 2014; 25:e99-109. [DOI: 10.1111/sms.12202] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2014] [Indexed: 01/25/2023]
Affiliation(s)
- D. Turner
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering; Swansea University; Swansea UK
- Diabetes Research Group; College of Medicine; Swansea University; Swansea UK
| | - S. Luzio
- Diabetes Research Group; College of Medicine; Swansea University; Swansea UK
- Abertawe Bro Morgannwg University Health Board; Singleton Hospital; Swansea UK
| | - B. J. Gray
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering; Swansea University; Swansea UK
- Diabetes Research Group; College of Medicine; Swansea University; Swansea UK
| | - G. Dunseath
- Diabetes Research Group; College of Medicine; Swansea University; Swansea UK
| | - E. D. Rees
- Abertawe Bro Morgannwg University Health Board; Singleton Hospital; Swansea UK
| | - L. P. Kilduff
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering; Swansea University; Swansea UK
| | - M. D. Campbell
- Department of Sport; Exercise and Rehabilitation; Faculty of Health and Life Sciences; Northumbria University; Newcastle-upon-Tyne UK
| | - D. J. West
- Department of Sport; Exercise and Rehabilitation; Faculty of Health and Life Sciences; Northumbria University; Newcastle-upon-Tyne UK
| | - S. C. Bain
- Diabetes Research Group; College of Medicine; Swansea University; Swansea UK
- Abertawe Bro Morgannwg University Health Board; Singleton Hospital; Swansea UK
| | - R. M. Bracken
- Applied Sports, Technology, Exercise and Medicine Research Centre, College of Engineering; Swansea University; Swansea UK
- Diabetes Research Group; College of Medicine; Swansea University; Swansea UK
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Cunningham DJ, West DJ, Owen NJ, Shearer DA, Finn CV, Bracken RM, Crewther BT, Scott P, Cook CJ, Kilduff LP. Strength and power predictors of sprinting performance in professional rugby players. J Sports Med Phys Fitness 2013; 53:105-111. [PMID: 23584316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
AIM The ability to accelerate and attain high levels of speed is an essential component of success in team sports; however, the physical qualities that underpin these activities remain unclear. This study aimed to determine some of the key strength and power predictors of speed within professional rugby union players. METHODS Twenty professional male rugby union players participated in this study. Subjects were tested for speed (0-10 m sprint and a flying 10 m sprint), strength (3 repetition maximum squat), lower body power (countermovement jumps [CMJ] and drop jumps [DJ]), reactive strength and leg spring stiffness. The strength and power variables were expressed as absolute values and relative values for analysis. RESULTS Both relative strength (r=-0.55, P<0.05) and relative power (-0.82, P<0.01) were negatively correlated with 10 m time. Leg spring stiffness and DJ contact time were also related to the flying 10 m time (r=-0.46 and 0.47, respectively, P<0.05) while reactive strength index was negatively related to both the 10 m and flying 10 m times (r=-0.60 and r=-0.62, P<0.05). CONCLUSION This study provides an insight into those physical attributes that underpin sprinting performance in professional rugby union players and specifically highlights the importance of relative strength and power in the expression and development of different speed components (e.g. acceleration, maximum velocity).
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Affiliation(s)
- D J Cunningham
- Health and Sport Portfolio, Talbot Building, Swansea University, Swansea, SA2 8PP, UK
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Affiliation(s)
- J. T. Manning
- Department of Psychology; Swansea University; Swansea; UK
| | - L. P. Kilduff
- Sport & Exercise Science Research Centre; Swansea University; Swansea; UK
| | - R. Trivers
- Department of Anthropology; Rutgers University; New Brunswick; USA
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15
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Crewther BT, Kilduff LP, Cook CJ, Cunningham DJ, Bunce P, Bracken RM, Gaviglio CM. Relationships between salivary free testosterone and the expression of force and power in elite athletes. J Sports Med Phys Fitness 2012; 52:221-227. [PMID: 22531608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
AIM This study examined the predictive relationships between the salivary free testosterone (T) concentrations of elite athletes and the expression of force and power. METHODS A group of elite male rugby players (N.=64) were assessed for peak force (PF), peak rate of force development (PRFD), force at 100 milliseconds (F100 ms) and 250 milliseconds (F250 ms) during an isometric mid-thigh pull (IMTP), and/or peak power (PP) and height during a countermovement jump (CMJ). Saliva samples were collected before testing and assayed for free T. Relationships between individual T concentrations and performance were assessed as a pooled group and 4 sub-groups of equal size. RESULTS As pooled data sets, none of the IMTP and CMJ performance variables were significantly correlated with free T in either the PF or PP groups (r=0.01-0.23). The PF and PP abilities of the 4 sub-groups were significantly different, so that PF1>PF2>PF3>PF4 (P<0.001) and PP1>PP2>PP3>PP4 (P<0.01). When the 4 sub-groups were analysed, the T concentrations of the PF4 group were significantly (P<0.05-0.01) correlated to PRFD (r=0.69) and F100 ms (r=0.55) during the IMTP, as was F100 ms in the PF1 group (r=0.66). In the PP1 group, free T also correlated to CMJ height (r=0.62). CONCLUSION The key conclusion is that the expression of force and power in an elite athletic group may be dependent, to some extent, on individual variation in salivary free T concentrations and existing strength or power levels. The current results also confirm that the grouping of elite athletes of mixed strength or power ability may bias predictive results in a manner not reflective of sub-groups within this population.
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Crewther BT, Kilduff LP, Cook CJ, Cunningham DJ, Bunce PJ, Bracken RM, Gaviglio CM. Scaling strength and power for body mass differences in rugby union players. J Sports Med Phys Fitness 2012; 52:27-32. [PMID: 22327083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
AIM This study on professional rugby union players was undertaken to: 1) confirm a relationship between body mass (BM) and peak force (PF) and peak power (PP); 2) evaluate the effect of ratio and allometric scaling on these relationships; and 3) compare the PF and PP abilities of different positional groups with each approach. METHODS Seventy-nine rugby players were assessed for PF during an isometric mid-thigh pull and/or countermovement jump PP. Athlete performance was normalized for BM using standard ratio and allometric scaling methods. The performance data from inside backs (IB), outside backs (OB), tight forwards (TF) and loose forwards (LF) were compared before and after scaling for BM. RESULTS Significant relationships were identified between BM and the absolute expression of PF (r=0.25) and PP (r=0.44). These relationships improved with the application of ratio scaling (r=-0.53 to -0.57), but were eliminated after allometric scaling with the derived exponents (r=0.00-0.02). No positional group differences in absolute and allometrically scaled PF and PP were seen, but ratio scaled performance favoured the lighter IB and OB over the heavier TF and/or LF (P<0.05). CONCLUSION The PF and PP abilities of professional rugby union players were related to individual BM and these relationships were differentially affected by ratio (enhanced) and allometric (removed) scaling. Ratio scaled performance favoured the lighter backs over the heavier forwards, which could be explained by their specific movement patterns within a game. Comparing positional data in such a manner may help practitioners to better quantify, assess and monitor the position-specific needs of athletes in team sport.
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Abstract
This study examined the validity of 2 kinematic systems for estimating force and power during squat jumps. 12 weight-trained males each performed single repetition squat jumps with a 20-kg, 40-kg, 60-kg and 80-kg load on a Kistler portable force plate. A commercial linear position transducer (Gymaware [GYM]) and accelerometer (Myotest® [MYO]) were attached to the bar to assess concentric peak force (PF) and peak power (PP). Across all loads tested, the GYM and MYO estimates of PF and PP were moderately to strongly correlated ( P≤0.05-0.001) with the force plate measurements ( R=0.59-0.87 and R=0.66-0.97), respectively. The mean PF and PP values were not significantly different between the 2 kinematic systems and the force plate, but the estimates did produce some systematic bias and relatively large random errors, especially with the 20-kg load (PF bias >170 N, PF error >335 N, PP bias >400 W, PP error >878 W). Some proportional bias was also identified. In summary, the estimation of PF and PP by a linear position transducer and accelerometer showed moderate to strong relative validity and equivalent absolute validity, but these estimates are limited by the presence of bias and large random errors.
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Affiliation(s)
- B T Crewther
- Imperial College, Institute of Biomedical Engineering, London, United Kingdom.
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Abstract
AIM This study examined the effects of reductions to pre-exercise rapid-acting insulin dose on changes in blood beta-hydroxybutyrate, glucose, acid-base balance and counter-regulatory hormone responses to prolonged running in individuals with Type 1 diabetes. METHODS Following ethical approval, seven participants with Type 1 diabetes (34±2 years, BMI 27±1 kg/m(2) ) completed this study. After preliminary testing, participants attended the laboratory four times, each time consuming a 1.12 MJ meal (60 g carbohydrate, 2 g fat, 2 g protein), with randomized amounts of their rapid-acting insulin: Full dose (mean 7.3±0.2 units), 75% dose (mean 5.4±0.1 units), 50% dose (mean 3.7±0.1 units) or 25% dose (mean 1.8±0.1 units). After 2-h rest, participants completed 45 min running at 70±1% peak rate of oxygen consumption (VO(2peak) ). Blood metabolites and hormones were recorded over the 2-h rest and 3-h recovery. Data were analysed using repeated-measures ANOVA. RESULTS Serum insulin peaked at 60 min in all conditions and was lowest after 25% insulin dose compared with full dose (P=0.03). After the 25% insulin dose immediately pre-exercise glucose concentration was higher than after the full or 50% dose (P<0.05). Resting beta-hydroxybutyrate gradually decreased during 2-h rest (P<0.05) with a similar post-exercise peak of beta-hydroxybutyrate at 3 h (P>0.05). Post-exercise blood pH increased for 5 min to a similar extent with all insulin doses , but the rise with the 25% dose was less compared with the full dose (P=0.01). Blood lactate and plasma catecholamines increased after running similarly with all insulin reduction conditions (P<0.05). Blood glucose area under the curve (BG(auc) ) after the 25% insulin dose was greater than after the 75% dose (P=0.02). CONCLUSION Ketogenesis following running was not influenced by reductions in pre-exercise rapid-acting insulin dose. This important preparatory strategy aids preservation of blood glucose but poses no greater risk to exercise-induced ketone body formation.
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Affiliation(s)
- R M Bracken
- Sports and Exercise Science Research Centre, School of Engineering, Swansea University, Singleton Park, Swansea, UK.
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Crewther BT, Kilduff LP, Cunningham D, Cook C, Yang GZ. Validity of two kinematic systems for calculating force and power during squat jumps. Br J Sports Med 2010. [DOI: 10.1136/bjsm.2010.078972.79] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Abstract
Squash is a popular racket sport that requires intermittent activity with frequent bursts of near maximal-intensity exercise. Consequently, effective physiological and thermoregulatory responses are important contributors to performance during squash match-play. Controlled field-based simulation protocols have been introduced in a growing number of sports, which allow sports scientists to investigate changes in physiology and the efficacy of various interventions in sport-specific contexts. This study aimed to develop an exercise protocol that simulates the physiological requirements of elite squash match-play. Eight elite junior squash players (age 16.2+/-0.8 years, height 1.76+/-0.06 m, body mass 61.3+/-5.9 kg; mean+/-s) completed the following in a randomized order: (1) a squash match against a player of similar standard and (2) a squash-specific incremental exercise protocol (multistage squash test [MST]) followed by the squash simulation protocol (SSP). The multistage squash test was continued for 18.0+/-1.0 min and elicited near maximal post-MST heart rates, blood lactate concentrations and ratings of perceived exertion (198+/-9 beats.min-1, 5.7+/-1.7 mmol.l-1 and 18+/-1, respectively). The SSP was 12.2 min in length compared with mean game length during competitive matches of 10.0+/-1.6 min (P=0.27). Peak heart rates were similar during the SSP and match-play (192+/-11 and 189+/-6 beats.min-1, respectively; P=0.44). Mean exercising heart rates were similar during the SSP (180+/-8 beats.min-1) and match-play (179+/-13 beats.min-1; P=0.73). Peak blood lactate concentrations during the SSP and match-play were 3.5+/-1.5 and 2.4+/-1.2 mmol.l-1 (P=0.07), respectively. Peak ratings of perceived exertion during the SSP and match-play were similar (17+/-2 and 17+/-2, respectively; P=0.64). It was concluded that the SSP closely replicated the demands of squash match-play in elite junior squash players. Furthermore, the SSP provides coaches and scientific support staff with a controlled squash-specific exercise protocol that has potential application in the objective investigation of a range of interventions such as training programmes, nutritional supplements and strategies to maintain core body temperature.
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Affiliation(s)
- M Kingsley
- Department of Sports Science, University of Wales, Swansea, UK.
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Hadjicharalambous M, Georgiades E, Kilduff LP, Turner AP, Tsofliou F, Pitsiladis YP. Influence of caffeine on perception of effort, metabolism and exercise performance following a high-fat meal. J Sports Sci 2006; 24:875-87. [PMID: 16815783 DOI: 10.1080/02640410500249399] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
This study examined the effects of caffeine, co-ingested with a high fat meal, on perceptual and metabolic responses during incremental (Experiment 1) and endurance (Experiment 2) exercise performance. Trained participants performed three constant-load cycling tests at approximately 73% of maximal oxygen uptake (VO2max) for 30 min at 20 degrees C (Experiment 1, n = 8) and to the limit of tolerance at 10 degrees C (Experiment 2, n = 10). The 30 min constant-load exercise in Experiment 1 was followed by incremental exercise (15 W . min-1) to fatigue. Four hours before the first test, the participants consumed a 90% carbohydrate meal (control trial); in the remaining two tests, the participants consumed a 90% fat meal with (fat + caffeine trial) and without (fat-only trial) caffeine. Caffeine and placebo were randomly assigned and ingested 1 h before exercise. In both experiments, ratings of perceived leg exertion were significantly lower during the fat + caffeine than fat-only trial (Experiment 1: P < 0.001; Experiment 2: P < 0.01). Ratings of perceived breathlessness were significantly lower in Experiment 1 (P < 0.01) and heart rate higher in Experiment 2 (P < 0.001) on the fat + caffeine than fat-only trial. In the two experiments, oxygen uptake, ventilation, blood [glucose], [lactate] and plasma [glycerol] were significantly higher on the fat + caffeine than fat-only trial. In Experiment 2, plasma [free fatty acids], blood [pyruvate] and the [lactate]:[pyruvate] ratio were significantly higher on the fat + caffeine than fat-only trial. Time to exhaustion during incremental exercise (Experiment 1: control: 4.9, s = 1.8 min; fat-only: 5.0, s = 2.2 min; fat + caffeine: 5.0, s = 2.2 min; P > 0.05) and constant-load exercise (Experiment 2: control: 116 (88 - 145) min; fat-only: 122 (96 - 144) min; fat + caffeine: 127 (107 - 176) min; P > 0.05) was not different between the fat-only and fat + caffeine trials. In conclusion, while a number of metabolic responses were increased during exercise after caffeine ingestion, perception of effort was reduced and this may be attributed to the direct stimulatory effect of caffeine on the central nervous system. However, this caffeine-induced reduction in effort perception did not improve exercise performance.
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Fuld JP, Kilduff LP, Neder JA, Pitsiladis Y, Lean MEJ, Ward SA, Cotton MM. Creatine supplementation during pulmonary rehabilitation in chronic obstructive pulmonary disease. Thorax 2005; 60:531-7. [PMID: 15994258 PMCID: PMC1747450 DOI: 10.1136/thx.2004.030452] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Skeletal muscle wasting and dysfunction are strong independent predictors of mortality in patients with chronic obstructive pulmonary disease (COPD). Creatine nutritional supplementation produces increased muscle mass and exercise performance in health. A controlled study was performed to look for similar effects in 38 patients with COPD. METHODS Thirty eight patients with COPD (mean (SD) forced expiratory volume in 1 second (FEV(1)) 46 (15)% predicted) were randomised to receive placebo (glucose polymer 40.7 g) or creatine (creatine monohydrate 5.7 g, glucose 35 g) supplements in a double blind trial. After 2 weeks loading (one dose three times daily), patients participated in an outpatient pulmonary rehabilitation programme combined with maintenance (once daily) supplementation. Pulmonary function, body composition, and exercise performance (peripheral muscle strength and endurance, shuttle walking, cycle ergometry) took place at baseline (n = 38), post loading (n = 36), and post rehabilitation (n = 25). RESULTS No difference was found in whole body exercise performance between the groups: for example, incremental shuttle walk distance mean -23.1 m (95% CI -71.7 to 25.5) post loading and -21.5 m (95% CI -90.6 to 47.7) post rehabilitation. Creatine increased fat-free mass by 1.09 kg (95% CI 0.43 to 1.74) post loading and 1.62 kg (95% CI 0.47 to 2.77) post rehabilitation. Peripheral muscle performance improved: knee extensor strength 4.2 N.m (95% CI 1.4 to 7.1) and endurance 411.1 J (95% CI 129.9 to 692.4) post loading, knee extensor strength 7.3 N.m (95% CI 0.69 to 13.92) and endurance 854.3 J (95% CI 131.3 to 1577.4) post rehabilitation. Creatine improved health status between baseline and post rehabilitation (St George's Respiratory Questionnaire total score -7.7 (95% CI -14.9 to -0.5)). CONCLUSIONS Creatine supplementation led to increases in fat-free mass, peripheral muscle strength and endurance, health status, but not exercise capacity. Creatine may constitute a new ergogenic treatment in COPD.
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Affiliation(s)
- J P Fuld
- Centre for Excercise Science and Medicine, Institute of Biological and Life Sciences, University of Glasgow, Glasgow, UK.
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Kilduff LP, Georgiades E, James N, Minnion RH, Mitchell M, Kingsmore D, Hadjicharlambous M, Pitsiladis YP. The Effects of Creatine Supplementation on Cardiovascular, Metabolic, and Thermoregulatory Responses during Exercise in the Heat in Endurance-Trained Humans. Int J Sport Nutr Exerc Metab 2004; 14:443-60. [PMID: 15467102 DOI: 10.1123/ijsnem.14.4.443] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The effects of creatine (Cr) supplementation on cardiovascular, metabolic, and thermoregulatory responses, and on the capacity of trained humans to perform prolonged exercise in the heat was examined. Endurance-trained males (n = 21) performed 2 constant-load exercise tests to exhaustion at 63 ± 5 % VO2max in the heat (ambient temperature: 30.3 ± 0.5 °C) before and after 7 d of Cr (20 g · d–1 ’ Cr + 140 g • d–1 glucose polymer) or placebo. Cr increased intraccl-lular water and reduced thermoregulatory and cardiovascular responses (e.g., heart rate, rectal temperature, sweat rate) but did not significantly increase time to exhaustion (47.0 ± 4.7 min vs. 49.7 ± 7.5 min, P = 0.095). Time to exhaustion was increased significantly in subjects whose estimated intramuscular Cr levels were substantially increased (“responders”: 47.3 ± 4.9 min vs. 51.7 ± 7.4 min, P = 0.031). Cr-induced hyperhydration can result in a more efficient thermoregulatory response during prolonged exercise in the heat.
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Affiliation(s)
- L P Kilduff
- Centre for Exercise Science and Medicine in the Institute of Biomedical and Life Sciences at the University of Glasgow, Glasgow, UK
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