Brown P.I.,Optimal Performance Ltd |
Brown P.I.,Nottingham Trent University |
Sharpe G.R.,Nottingham Trent University |
Johnson M.A.,Nottingham Trent University
Medicine and Science in Sports and Exercise | Year: 2010
PURPOSE: The purpose of this study was to investigate the effects of inspiratory threshold loading (ITL) and inspiratory muscle training (IMT) on blood lactate concentration ([lac]B) and acid-base balance after maximal incremental cycling. METHODS: Eighteen subjects were divided into a control (n = 9) or an IMT group (n = 9). Before and after a 6-wk intervention, subjects completed two maximal incremental cycling tests followed by 20 min of recovery with (ITL) or without (passive recovery (PR)) a constant inspiratory resistance (15 cm H2O). The IMT group performed 6 wk of pressure threshold IMT at 50% maximal inspiratory mouth pressure. Throughout recovery, acid-base balance was quantified using the physicochemical approach by measuring the strong ion difference ([SID] = [Na+] + [K+]-[Cl-] + [lac-]), the total concentration of weak acids ([Atot -]), and the partial pressure of carbon dioxide (PCO2). RESULTS: After the intervention, maximal inspiratory mouth pressure increased in the IMT group only (+34%). No differences in lactate clearance were observed between PR and ITL before the intervention in both groups and after the intervention in the control group. After IMT, relative to PR, [lac -]B was reduced throughout ITL (minutes 2-20) by 0.66 ± 1.28 mmol•L (P < 0.05), and both the fast (lactate exchange) and the slow (lactate clearance) velocity constants of the lactate recovery kinetics were increased (P < 0.05). Relative to pre-IMT, ITL reduced plasma [H+], which was accounted for by an IMT-mediated increase in [SID] due almost exclusively to a 1.7-mmol•L reduction in [lac-] B. CONCLUSIONS: After maximal exercise, ITL affected lactate recovery kinetics only after IMT. Our data support the notion that the inspiratory muscles are capable of lactate clearance that increases [SID] and reduces [H+]. These effects may facilitate subsequent bouts of high-intensity exercise. © 2010 by the American College of Sports Medicine.
Ingham S.A.,Loughborough University |
Pringle J.S.,Loughborough University |
Hardman S.L.,English Institute of Sport |
Fudge B.W.,Loughborough University |
Richmond V.L.,Optimal Performance Ltd
International Journal of Sports Physiology and Performance | Year: 2013
Purpose: This study examined parameters derived from both an incremental step-wise and a ramp-wise graded rowing exercise test in relation to rowing performance. Methods: Discontinuous step-wise incremental rowing to exhaustion established lactate threshold (LT), maximum oxygen consumption (VO 2maxSTEP), and power associated with VO2max (W VO 2max). A further continuous ramp-wise test was undertaken to derive ventilatory threshold (VT), maximum oxygen consumption (VO2maxRAMP), and maximum minute power (MMW). Results were compared with maximal 2000-m ergometer time-trial power. Results: The strongest correlation with 2000-m power was observed for MMW (r = .98, P < .001), followed by W VO2max (r = .96; P < .001). The difference between MMW and W VO2max compared with the mean of MMW/W VO2max showed a widening bias with a greater difference coincident with greater power. However, this bias was reduced when expressed as a ratio term and when a baseline VO2 was accounted for. There were no differences (P = .85) between measures of VO 2maxSTEP and VO2maxRAMP; rather, the measures showed strong association (r = .97, P < .001, limits of agreement = -0.43 to 0.33 L/min). The power at LT and VT did not differ (P = .6), and a significant association was observed (r = .73, P = .001, limits of agreement = -54.3 to 20.2 W, SEE = 26.1). Conclusions: This study indicates that MMW demonstrates a strong association with ergometer rowing performance and thus may have potential as an influential monitoring tool for rowing athletes. © 2013 Human Kinetics, Inc.
Loney T.,United Arab Emirates University |
Carter J.M.,Optimal Performance Ltd |
Linnane D.M.,Optimal Performance Ltd
Society of Petroleum Engineers - SPE Middle East Health, Safety, Security, and Environment Conf. and Exhibition 2012, MEHSSE - Sustaining World Energy Through an Integrated HSSE and Business Approach | Year: 2012
Description. The Active Workplace Programme was a three-week initiative to increase physical activity within an office worksite in Abu Dhabi. Twenty-four employees (10 male) were provided with a pedometer to monitor their daily step count which was recorded at the end of their shift. Employees were equally divided into two teams and competed over a number of daily and weekly pedometer-based physical activity challenges, ranging from a virtual footrace from A1 Ain to Abu Dhabi to the Burj Khalifa stair climbing contest. The office environment was modified to encourage physical activity and changes included transforming the main building thoroughfare into a dynamic walkway by installing various obstacles (e.g. mini-trampolines, 12-inch hurdles, a hop scotch grid, step-up benches) and providing offices with stretching mats, Swiss balls, and cycle ergometers for employee use throughout the day. Each day of the week focussed on a different activity such as Walk & Talk Sunday when active meetings were promoted and Office Yoga Wednesday when employees were encouraged to participate in desk station yoga workouts. Applications. Workplaces are important arenas for health promotion and the Active Workplace Programme can be implemented in any occupational setting allowing physical activity to be engineered into the daily work schedule without interfering with occupational duties. Results, Observations and Conclusions. Mean (± SD) daily step count increased from 4999 ± 3776 steps/day at baseline to 6482 ± 4674 steps/day at the end of the programme (P=.063, effect size = 0.34). The Active Workplace Programme increased ambulatory physical activity over a three week period and has shown that a pedometer offers a practical, while cost-effective approach to increasing daily physical activity in office-based employees. Significance of Subject Matter/Technical Contributions. Direct costs to the petroleum industry of morbidity attributed to non-communicable disease are rising; hence, workplace prevention programmes are urgently required. In addition to increasing occupational physical activity, implementing the Active Workplace Programme within the petroleum industry has a number of potential benefits for both the organisation and employees including reducing absenteeism and staff turnover, increasing productivity, and creating a healthier, happier workforce with enhanced staff morale and improved worklife balance. Copyright 2012, Society of Petroleum Engineers.
Horner F.,University of Bath |
Horner F.,Optimal Performance Ltd |
Bilzon J.L.,University of Bath |
Rayson M.,Optimal Performance Ltd |
And 5 more authors.
Journal of Sports Sciences | Year: 2013
This study developed a multivariate model to predict free-living energy expenditure (EE) in independent military cohorts. Two hundred and eighty-eight individuals (20.6±3.9 years, 67.9±12.0 kg, 1.71±0.10 m) from 10 cohorts wore accelerometers during observation periods of 7 or 10 days. Accelerometer counts (PAC) were recorded at 1-minute epochs. Total energy expenditure (TEE) and physical activity energy expenditure (PAEE) were derived using the doubly labeled water technique. Data were reduced to n=155 based on wear-time. Associations between PAC and EE were assessed using allometric modelling. Models were derived using multiple log-linear regression analysis and gender differences assessed using analysis of covariance. In all models PAC, height and body mass were related to TEE (P < 0.01). For models predicting TEE (r2=0.65, SE=462 kcal · d-1 (13.0%)), PAC explained 4% of the variance. For models predicting PAEE (r2=0.41, SE=490 kcal · d-1 (32.0%)), PAC accounted for 6% of the variance. Accelerometry increases the accuracy of EE estimation in military populations. However, the unique nature of military life means accurate prediction of individual free-living EE is highly dependent on anthropometric measurements. © 2013 Taylor & Francis.
Richmond V.L.,Optimal Performance Ltd |
Wilkinson D.M.,Optimal Performance Ltd |
Blacker S.D.,Optimal Performance Ltd |
Horner F.E.,Optimal Performance Ltd |
And 3 more authors.
Physiological Measurement | Year: 2013
This study assessed the validity of insulated skin temperature (T is) to predict rectal temperature (Tre) for use as a non-invasive measurement of thermal strain to reduce the risk of heat illness for emergency service personnel. Volunteers from the Police, Fire and Rescue, and Ambulance Services performed role-related tasks in hot (30 °C) and neutral (18 °C) conditions, wearing service specific personal protective equipment. Insulated skin temperature and micro climate temperature (T mc) predicted Tre with an adjusted r2 = 0.87 and standard error of the estimate (SEE) of 0.19 °C. A bootstrap validation of the equation resulted in an adjusted r2 = 0.85 and SEE = 0.20 °C. Taking into account the 0.20 °C error, the prediction of T re resulted in a sensitivity and specificity of 100% and 91%, respectively. Insulated skin temperature and Tmc can be used in a model to predict Tre in emergency service personnel wearing CBRN protective clothing with an SEE of 0.2 °C. However, the model is only valid for Tis over 36.5 °C, above which thermal stability is reached between the core and the skin. © 2013 Institute of Physics and Engineering in Medicine.