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Beaven, Martyn
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Publications (10 of 29) Show all publications
McGawley, K., Platt, S., Beaven, M. & Björklund, G. (2015). The validity and reliability of a four-minute running time trial in assessing VO2max and performance. In: : . Paper presented at Endurance Research Conference.
Open this publication in new window or tab >>The validity and reliability of a four-minute running time trial in assessing VO2max and performance
2015 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

INTRODUCTION: Incremental tests to volitional exhaustion are widely used to assess VO2max. However, the need to establish starting workloads, stage durations, and step increments make administration problematic. Moreover, the validity of such tests has been questioned (Beltrami et al., 2012, Br J Sports Med, 46:23-29; Mauger & Sculthorpe, 2012, Br J Sports Med, 46:59-63). Short time trials represent a simpler and more ecologically valid alternative to assess VO2max and performance across exercise modes (Crouter et al., 2001, Med Sci Sports Exerc, 33:644-647; Ansley et al., 2004, Med Sci Sports Exerc, 36:1819-1825; McGawley & Holmberg, 2014, Int J Sports Physiol Perform 9:32-40). The aim of the current study was to assess the reliability and validity of a treadmill running time trial (RunTT) for the assessment of VO2max and performance.

 

METHODS: Ten recreational athletes (5 males, 5 females; 32 ± 7 y) completed five incremental tests to exhaustion (INC) including a verification phase (VER) on a treadmill and five, 4-min RunTTs. The order of INC+VER and RunTT trials was alternated and counter-balanced. The INC and VER protocols were externally controlled, with incline increasing by 1% every minute during the INC. By contrast, the RunTT protocol was athlete controlled, with running speed self-adjusted via a laser system fitted to the treadmill (and incline fixed at 1%). Performance was measured as time to exhaustion for INC and VER and distance covered for RunTT. Heart rate (HR) was monitored continuously throughout each protocol. RPE and lactate were assessed immediately post-exercise and at 1-min intervals for four minutes post-exercise, respectively.

 

RESULTS: The CV for VO2max was not significantly different between INC, VER and RunTT (1.9, 2.2 and 1.7%, respectively) but for performance was significantly different between all types of test (4.5, 9.7 and 1.8% for INC, VER and RunTT, respectively; P<0.005). VO2max was significantly higher for INC compared with VER and RunTT (59.2 versus 58.0 and 57.6 mL/kg/min, respectively; P<0.001) and Bland-Altman limits of agreement showed a bias ± 95% of 1.5 ± 3.1 mL/kg/min for INC versus RunTT. Peak HR was also significantly higher for INC compared with RunTT (181 versus 177 beats/min; P<0.001), while peak RER and RPE were not different. Peak lactate was higher after RunTT compared with INC (10.13 versus 9.22 mmol/L; P<0.001).

 

CONCLUSION: A RunTT appears to provide more reliable performance data in comparison to INC; however, VO2max values were ~ 1.5 mL/kg/min lower and peak lactate was significantly higher.

National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:miun:diva-25883 (URN)
Conference
Endurance Research Conference
Available from: 2015-09-18 Created: 2015-09-18 Last updated: 2015-12-08Bibliographically approved
Ekström, J. G. & Beaven, C. M. (2014). Effects of blue light and caffeine on mood. Psychopharmacology, 231(18), 3677-3683
Open this publication in new window or tab >>Effects of blue light and caffeine on mood
2014 (English)In: Psychopharmacology, ISSN 0033-3158, E-ISSN 1432-2072, Vol. 231, no 18, p. 3677-3683Article in journal (Refereed) Published
Abstract [en]

Both short wavelength (blue) light and caffeine have been studied for their mood enhancing effects on humans. The ability of blue light to increase alertness, mood and cognitive function via non-image forming neuropathways has been suggested as a non-pharmacological countermeasure for depression across a range of occupational settings. This experimental study compared blue light and caffeine and aimed to test the effects of blue light/placebo (BLU), white light/240-mg caffeine (CAF), blue light/240-mg caffeine (BCAF) and white light/placebo (PLA), on mood. A randomised, controlled, crossover design study was used, in a convenience population of 20 healthy volunteers. The participants rated their mood on the Swedish Core Affect Scales (SCAS) prior to and after each experimental condition to assess the dimensions of valence and activation. There was a significant main effect of light (p = 0.009), and the combination of blue light and caffeine had clear positive effects on core effects (ES, ranging from 0.41 to 1.20) and global mood (ES, 0.61 +/- 0.53). The benefits of the combination of blue light and caffeine should be further investigated across a range of applications due to the observed effects on the dimensions of arousal, valence and pleasant activation.

Keywords
Arousal, Drug potentiation, Phototherapy, Valence
National Category
Sport and Fitness Sciences Psychology
Identifiers
urn:nbn:se:miun:diva-23225 (URN)10.1007/s00213-014-3503-8 (DOI)000341371300002 ()2-s2.0-84906937441 (Scopus ID)
Available from: 2014-10-16 Created: 2014-10-16 Last updated: 2017-12-05Bibliographically approved
Cook, C. J., Kilduff, L. P. & Beaven, C. M. (2014). Improving strength and power in trained athletes with 3 weeks of occlusion training. International Journal of Sports Physiology and Performance, 9(1), 166-172
Open this publication in new window or tab >>Improving strength and power in trained athletes with 3 weeks of occlusion training
2014 (English)In: International Journal of Sports Physiology and Performance, ISSN 1555-0265, E-ISSN 1555-0273, Vol. 9, no 1, p. 166-172Article in journal (Refereed) Published
Abstract [en]

Purpose: To examine the effects of moderate-load exercise with and without blood-flow restriction (BFR) on strength, power, and repeated-sprint ability, along with acute and chronic salivary hormonal parameters. Methods: Twenty male semiprofessional rugby union athletes were randomized to a lower-body BFR intervention (an occlusion cuff inflated to 180 mmHg worn intermittently on the proximal thighs) or a control intervention that trained without occlusion in a crossover design. Experimental sessions were performed 3 times a week for 3 wk with 5 sets of 5 repetitions of bench press, leg squat, and pull-ups performed at 70% of 1-repetition maximum. Results: Greater improvements were observed (occlusion training vs control) in bench press (5.4 ± 2.6 vs 3.3 ± 1.4 kg), squat (7.8 ± 2.1 vs 4.3 ± 1.4 kg), maximum sprint time (-0.03 ± 0.03 vs -0.01 ± 0.02 s), and leg power (168 ± 105 vs 68 ± 50 W). Greater exercise-induced salivary testosterone (ES 0.84-0.61) and cortisol responses (ES 0.65-0.20) were observed after the occlusion intervention sessions compared with the nonoccluded controls; however, the acute cortisol increases were attenuated across the training block. Conclusions: Occlusion training can potentially improve the rate of strength-training gains and fatigue resistance in trained athletes, possibly allowing greater gains from lower loading that could be of benefit during high training loads, in competitive seasons, or in a rehabilitative setting. The clear improvement in bench-press strength resulting from lower-body occlusion suggests a systemic effect of BFR training. © 2014 Human Kinetics, Inc.

Keywords
Blood-flow restriction, Cortisol, Testosterone, Training adaptation
National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:miun:diva-21353 (URN)10.1123/IJSPP.2013-0018 (DOI)000333364200025 ()2-s2.0-84892925225 (Scopus ID)
Note

Language of Original Document: English

Available from: 2014-02-18 Created: 2014-02-18 Last updated: 2017-12-06Bibliographically approved
Cook, C. J., Kilduff, L. P., Crewther, B. T., Beaven, M. & West, D. J. (2014). Morning based strength training improves afternoon physical performance in rugby union players. Journal of Science and Medicine in Sport, 17(3), 317-321
Open this publication in new window or tab >>Morning based strength training improves afternoon physical performance in rugby union players
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2014 (English)In: Journal of Science and Medicine in Sport, ISSN 1878-1861, Vol. 17, no 3, p. 317-321Article in journal (Refereed) Published
Abstract [en]

ObjectivesTo determine if a morning training session could alter afternoon physical performance. Moreover, as testosterone (T) and cortisol (C) concentrations are significant predictors of physical performance, and both show circadian declines across the day, we examined the effects of morning training on diurnal T and C responses. DesignEighteen semi-professional rugby union players completed this randomised and counter-balanced study. MethodsFollowing morning saliva collection (0900. h), players completed a control (rested), Sprint (5 × 40 m) or Weights (3 repetition-maximum [RM] bench press and squat) trial. In the afternoon (15:00. h) of each trial, a further saliva sample was collected before players completed a performance test (3RM back squat and bench press, 40. m sprint, countermovement jump [CMJ]). ResultsSalivary T concentrations declined from am to pm under Control and Sprint, but not under Weights. Delta T, from am to pm, was greater under Control (-10.9±2.4pgml-1) compared to Sprints (-6.2±7.1pgml-1) and Weights (-1.2±5.5pgml-1) (p≤0.001). Delta C, from am to pm, was greater under Control compared to both Sprint and Weights (p&lt;0.05). Players elicited better CMJ peak power, 40-m time, 3RM bench and squat performance under Weights compared with Control and Sprint (p&lt;0.05). Faster 40-m times were seen under Sprint, when compared to Control (p&lt;0.05). ConclusionsPerforming morning strength training is associated with improved physical performance in the afternoon. Additionally, the circadian decline in T concentrations appeared offset by morning training. However, it is unclear if T concentrations are, in part, causal of these improved responses or simply a reflective marker. © 2013 Sports Medicine Australia.

Keywords
Potentiation, Power, Steroid hormone, Strength, Testosterone
National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:miun:diva-22039 (URN)10.1016/j.jsams.2013.04.016 (DOI)000336240200014 ()2-s2.0-84899659648 (Scopus ID)
Note

Language of Original Document: English

Available from: 2014-06-02 Created: 2014-05-30 Last updated: 2014-07-22Bibliographically approved
Beaven, M., Willis, S., Cook, C. & Holmberg, H.-C. (2014). Physiological comparison of concentric and eccentric arm cycling in males and females. PLoS ONE, 5(9), Art. no. e112079
Open this publication in new window or tab >>Physiological comparison of concentric and eccentric arm cycling in males and females
2014 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 5, no 9, p. Art. no. e112079-Article in journal (Refereed) Published
Abstract [en]

Lower body eccentric exercise is well known to elicit high levels of muscular force with relatively low cardiovascular and metabolic strain. As a result, eccentric exercise has been successfully utilised as an adaptive stressor to improve lower body muscle function in populations ranging from the frail and debilitated, to highly-trained individuals. Here we investigate the metabolic, cardiorespiratory, and energy costs of upper body eccentric exercise in a healthy population. Seven men and seven women performed 4-min efforts of eccentric (ECC) or concentric (CON) arm cycling on a novel arm ergometer at workloads corresponding to 40, 60, and 80% of their peak workload as assessed in an incremental concentric trial. The heart rate, ventilation, cardiac output, respiratory exchange ratio, and blood lactate concentrations were all clearly greater in CON condition at all of the relative workloads (all p<0.003). Effect size calculations demonstrated that the magnitude of the differences in VO2 and work economy between the ECC and CON exercise ranged from very large to extremely large; however, in no case did mechanical efficiency (ηMECH) differ between the conditions (all p>0.05). In contrast, delta efficiency (ηΔ), as previously defined by Coyle and colleagues in 1992, demonstrated a sex difference (men>women; p<0.05). Sex differences were also apparent in arteriovenous oxygen difference and heart rate during CON. Here, we reinforce the high-force, low cost attributes of eccentric exercise which can be generalised to the muscles of the upper body. Upper body eccentric exercise is likely to form a useful adjunct in debilitative, rehabilitative, and adaptive clinical exercise programs; however, reports of a shift towards an oxidative phenotype should be taken into consideration by power athletes. We suggest delta efficiency as a sensitive measure of efficiency that allowed the identification of sex differences.

National Category
Physiology Sport and Fitness Sciences
Identifiers
urn:nbn:se:miun:diva-23787 (URN)10.1371/journal.pone.0112079 (DOI)000344556900109 ()2-s2.0-84910609082 (Scopus ID)
Available from: 2014-12-16 Created: 2014-12-16 Last updated: 2018-01-11Bibliographically approved
West, D. J., Cook, C. J., Beaven, C. M. & Kilduff, L. P. (2014). THE INFLUENCE OF THE TIME OF DAY ON CORE TEMPERATURE AND LOWER BODY POWER OUTPUT IN ELITE RUGBY UNION SEVENS PLAYERS. JOURNAL OF STRENGTH AND CONDITIONING RESEARCH, 28(6), 1524-1528
Open this publication in new window or tab >>THE INFLUENCE OF THE TIME OF DAY ON CORE TEMPERATURE AND LOWER BODY POWER OUTPUT IN ELITE RUGBY UNION SEVENS PLAYERS
2014 (English)In: JOURNAL OF STRENGTH AND CONDITIONING RESEARCH, ISSN 1533-4287, Vol. 28, no 6, p. 1524-1528Article in journal (Refereed) Published
Abstract [en]

Core temperature typically displays a low circadian in the morning before peaking later in the day, and these changes occur within small physiological ranges. Body temperature plays an important role in physical performance, and some athletes may be required to train and compete in both the morning and evening. However, the influence of the circadian change in body temperature and its influence on physical performance in elite athletes are unclear. This study examined the effects of the time of day on core temperature and lower body power output in elite rugby union sevens players. Sixteen elite rugby union sevens players completed morning (in AM) countermovement jump and core temperature (T-core) measurement, which were then repeated later the same day (in PM). Countermovement jump was processed for peak power output (PPO). Data were analyzed using paired samples t-test and Pearson's product moment correlation and are presented in mean +/- SD. T-core significantly increased from AM to PM (AM, 36.92 +/- 0.23 vs. PM, 37.18 +/- 0.188 degrees C; P < 0.001) with PPO significantly increasing from AM to PM in all 16 players (AM, 5248 +/- 366 vs. PM, 5413 +/- 361 W; P < 0.001). The delta change in T-core (0.26 +/- 0.138 degrees C) and PPO (164 +/- 78 W) was significantly related (r = 0.781; P < 0.001). In conclusion, small circadian changes in core temperature can influence physical performance in elite athletes. Coaches should seek to use strategies, which may raise morning body temperature to offset the circadian low in the morning.

Keywords
Body temperature, Circadian rhythm, Performance
National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:miun:diva-22606 (URN)000337152800005 ()2-s2.0-84902077305 (Scopus ID)
Available from: 2014-08-19 Created: 2014-08-19 Last updated: 2015-07-01Bibliographically approved
Hebert-Losier, K. & Beaven, C. M. (2014). THE MARS FOR SQUAT, COUNTERMOVEMENT, AND STANDING LONG JUMP PERFORMANCE ANALYSES: ARE MEASURES REPRODUCIBLE?. JOURNAL OF STRENGTH AND CONDITIONING RESEARCH, 28(7), 1849-1857
Open this publication in new window or tab >>THE MARS FOR SQUAT, COUNTERMOVEMENT, AND STANDING LONG JUMP PERFORMANCE ANALYSES: ARE MEASURES REPRODUCIBLE?
2014 (English)In: JOURNAL OF STRENGTH AND CONDITIONING RESEARCH, ISSN 1533-4287, Vol. 28, no 7, p. 1849-1857Article in journal (Refereed) Published
Abstract [en]

The MARS for squat, countermovement, and standing long jump performance analyses: are measures reproducible? J Strength Cond Res 28(7): 18491857, 2014-Jump tests are often used to assess the effect of interventions because their outcomes are reported valid indicators of functional performance. In this study, we examined the reproducibility of performance parameters from 3 common jump tests obtained using the commercially available Kistler Measurement, Analysis and Reporting Software (MARS). On 2 separate days, 32 men performed 3 squat jumps (SJs), 3 countermovement jumps (CMJs), and 3 standing long jumps (LJs) on a Kistler force-plate. On both days, the performance measures from the best jump of each series were extracted using the MARS. Changes in the mean scores, intraclass correlation coefficients (ICCs), and coefficients of variations (CVs) were computed to quantify the between-day reproducibility of each parameter. Moreover, the reproducibility quantifiers specific to the 3 separate jumps were compared using nonparametric tests. Overall, an acceptable between-day reproducibility (mean +/- SD, ICC, and CV) of SJ (0.88 +/- 0.06 and 7.1 +/- 3.8%), CMJ (0.84 +/- 0.17 and 5.9 +/- 4.1%), and LJ (0.80 +/- 0.13 and 8.1 +/- 4.1%) measures was found using the MARS, except for parameters directly relating to the rate of force development (i.e., time to maximal force) and change in momentum during countermovement (i.e., negative force impulse) where reproducibility was lower. A greater proportion of the performance measures from the standing LJs had low ICCs and/or high CVs values most likely owing to the complex nature of the LJ test. Practitioners and researchers can use most of the jump test parameters from the MARS with confidence to quantify changes in the functional ability of individuals over time, except for those relating to the rate of force development or change in momentum during countermovement phases of jumps.

Keywords
force, kinetics, power, reliability, testing
National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:miun:diva-22591 (URN)10.1519/JSC.0000000000000343 (DOI)000338782600009 ()2-s2.0-84905972315 (Scopus ID)
Available from: 2014-08-20 Created: 2014-08-19 Last updated: 2014-09-10Bibliographically approved
Beaven, C. M. & Ekstrom, J. (2013). A Comparison of Blue Light and Caffeine Effects on Cognitive Function and Alertness in Humans. PLoS ONE, 8(10), e76707
Open this publication in new window or tab >>A Comparison of Blue Light and Caffeine Effects on Cognitive Function and Alertness in Humans
2013 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 10, p. e76707-Article in journal (Refereed) Published
Abstract [en]

The alerting effects of both caffeine and short wavelength (blue) light have been consistently reported. The ability of blue light to enhance alertness and cognitive function via non-image forming neuropathways have been suggested as a non-pharmacological countermeasure for drowsiness across a range of occupational settings. Here we compare and contrast the alerting and psychomotor effects of 240 mg of caffeine and a 1-h dose of similar to 40 lx blue light in a non-athletic population. Twenty-one healthy subjects performed a computer-based psychomotor vigilance test before and after each of four randomly assigned trial conditions performed on different days: white light/placebo; white light/240 mg caffeine; blue light/placebo; blue light/240 mg caffeine. The Karolinska Sleepiness Scale was used to assess subjective measures of alertness. Both the caffeine only and blue light only conditions enhanced accuracy in a visual reaction test requiring a decision and an additive effect was observed with respect to the fastest reaction times. However, in a test of executive function, where a distraction was included, caffeine exerted a negative effect on accuracy. Furthermore, the blue light only condition consistently outperformed caffeine when both congruent and incongruent distractions were presented. The visual reactions in the absence of a decision or distraction were also enhanced in the blue light only condition and this effect was most prominent in the blue-eyed participants. Overall, blue light and caffeine demonstrated distinct effects on aspects of psychomotor function and have the potential to positively influence a range of settings where cognitive function and alertness are important. Specifically, despite the widespread use of caffeine in competitive sporting environments, the possible impact of blue light has received no research attention.

National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:miun:diva-20637 (URN)10.1371/journal.pone.0076707 (DOI)000325501300082 ()2-s2.0-84885077165 (Scopus ID)
Available from: 2013-12-11 Created: 2013-12-11 Last updated: 2017-12-06Bibliographically approved
Beaven, C. M., Maulder, P., Pooley, A., Kilduff, L. & Cook, C. (2013). Effects of caffeine and carbohydrate mouth rinses on repeated sprint performance. Applied Physiology, Nutrition and Metabolism, 38(6), 633-637
Open this publication in new window or tab >>Effects of caffeine and carbohydrate mouth rinses on repeated sprint performance
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2013 (English)In: Applied Physiology, Nutrition and Metabolism, ISSN 1715-5312, E-ISSN 1715-5320, Vol. 38, no 6, p. 633-637Article in journal (Refereed) Published
Abstract [en]

Introduction: Our purpose was to examine the effectiveness of carbohydrate and caffeine mouth rinses on enhancing repeated sprint ability. Previously, beneficial effects of a carbohydrate mouth rinse (without ingestion) on endurance performance have been related to changes in brain activity. Caffeine ingestion has also demonstrated positive effects on sprint performance. However, the effects of carbohydrate or caffeine mouth rinses on intermittent sprints have not previously been examined. Methods: Twelve males performed 5 x 6 s sprints interspersed by 24 s of active recovery on a cycle ergometer. Twenty-five ml of either a non-caloric placebo, 6% glucose, or 1.2% caffeine solution was rinsed in the mouth for 5 s prior to each sprint in a double-blinded and balanced, cross-over design. Post-exercise maximal heart rate and perceived exertion were recorded along with power measures. A second experiment compared a combined caffeine-carbohydrate rinse with carbohydrate-only. Results: Compared to the placebo mouth rinse, carbohydrate substantially increased Sprint 1 peak power (22.1 ±19.5 W; ES: 0.81), and both caffeine (26.9 ±26.9 W; ES: 0.71) and carbohydrate (39.1 ±25.8 W; ES: 1.08) improved mean power in Sprint 1. Experiment 2 demonstrated that a combination of caffeine and carbohydrate improved Sprint 1 power production compared to carbohydrate alone (36.0 ±37.3 W; ES: 0.81). Conclusions: Carbohydrate and/or caffeine mouth rinses may rapidly enhance power production which could have benefits for specific short sprint exercise performance. The ability of a mouth rinse intervention to rapidly improve maximal exercise performance in the absence of fatigue suggests a central mechanism.

Keywords
Cycle sprints, Fatigue, Mouth wash, Power
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:miun:diva-18260 (URN)10.1139/apnm-2012-0333 (DOI)000319741200007 ()2-s2.0-84878757503 (Scopus ID)
Available from: 2013-01-13 Created: 2013-01-13 Last updated: 2017-12-06Bibliographically approved
Beaven, C. M. (2013). Electrostimulation's enhancement of recovery during a rugby preseason. International Journal of Sports Physiology and Performance, 8(1), 92-98
Open this publication in new window or tab >>Electrostimulation's enhancement of recovery during a rugby preseason
2013 (English)In: International Journal of Sports Physiology and Performance, ISSN 1555-0265, E-ISSN 1555-0273, Vol. 8, no 1, p. 92-98Article in journal (Refereed) Published
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:miun:diva-18258 (URN)23302142 (PubMedID)
Available from: 2013-01-13 Created: 2013-01-13 Last updated: 2017-12-06Bibliographically approved
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