Effects of synchronous music on treadmill running among elite triathletes

This is the post-print version of the final paper published in Journal of Science and Medicine in Sport. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2011 Elsevier B.V.Objectives: Music can provide ergogenic, psychological, and psychophysical benefits during physical activity, especially when movements are performed synchronously with music. The present study developed the train of research on synchronous music and extended it to elite athletes. Design: Repeated-measures laboratory experiment. Method: Elite triathletes (n = 11) ran in time to self-selected motivational music, a neutral equivalent and a no-music control during submaximal and exhaustive treadmill running. Measured variables were time-to-exhaustion, mood responses, feeling states, RPE, blood lactate concentration, oxygen consumption and running economy. Results: Time-to-exhaustion was 18.1% and 19.7% longer, respectively, when running in time to motivational and neutral music, compared to no music. Mood responses and feeling states were more positive with motivational music compared to either neutral music or no music. RPE was lowest for neutral music and highest for the no-music control. Blood lactate concentrations were lowest for motivational music. Oxygen consumption was lower with music by 1.0%–2.7%. Both music conditions were associated with better running economy than the no-music control. Conclusions: Although neutral music did not produce the same level of psychological benefits as motivational music, it proved equally beneficial in terms of time-to-exhaustion and oxygen consumption. In functional terms, the motivational qualities of music may be less important than the prominence of its beat and the degree to which participants are able to synchronise their movements to its tempo. Music provided ergogenic, psychological and physiological benefits in a laboratory study and its judicious use during triathlon training should be considered.QAS Centre of Excellence for Applied Sport Science Researc

Overcommitment to work is associated with changes in cardiac sympathetic regulation.

Objective: Work stress is associated with an increased risk for cardiovascular disease (CVD). Exaggerated cardiovascular reactivity to work-related stressors or incomplete recovery after work is a proposed mechanism underlying this increase in risk. This study examined the effects of work stress on 24-hour profiles of the pre-ejection period (PEP), a measure of cardiac sympathetic activity, obtained from ambulatory measurement of the impedance cardiogram. Methods: A total of 67 male white-collar workers (age 47.1 ± 5.2) underwent ambulatory monitoring on 2 workdays and 1 non-workday. Work stress was defined according to Siegrist's model as 1) a combination of high effort and low reward at work (high imbalance) or 2) an exhaustive work-related coping style (high overcommitment). Results: High overcommitment was associated with shorter absolute PEP levels during all periods on all 3 measurement days, reduced wake-to-sleep PEP differences and reduced PEP variability, as indexed by the SD. Conclusions: Overcommitment to work was associated with an increase in basal sympathetic drive and a reduction in the dynamic range of cardiac sympathetic regulation. Both findings are compatible with the hypothesis that overcommitment induces β-receptor down-regulation

Effects of variation in posture and respiration on RSA and pre-ejection period

The extent to which variation in posture and respiration can confound pre-ejection period and respiratory sinus arrhythmia (RSA) as indices of cardiac sympatho-vagal activity was examined. Within-subjects changes in these measures were assessed in 36 subjects during different postures and (paced) respiratory frequencies. Changes from supine to sitting to standing led to reduced RSA values and longer pre-ejection periods, reflecting the known decrease in vagal but not the increase of sympathetic activity. Multilevel path analysis showed that within-subjects changes in sympatho-vagal balance were faithfully reflected by changes in interbeat interval, but imperfectly by changes in RSA and pre-ejection period. It was concluded that pre-ejection period should be stratified for posture and RSA for respiratory frequency to reliably index changes in sympatho-vagal balance when these factors are prone to change (e.g., during 24-h ambulatory recording). Copyright © 2005 Society for Psychophysiological Research

Enhanced Fatty Acid Oxidation and FATP4 Protein Expression after Endurance Exercise Training in Human Skeletal Muscle

FATP1 and FATP4 appear to be important for the cellular uptake and handling of long chain fatty acids (LCFA). These findings were obtained from loss- or gain of function models. However, reports on FATP1 and FATP4 in human skeletal muscle are limited. Aerobic training enhances lipid oxidation; however, it is not known whether this involves up-regulation of FATP1 and FATP4 protein. Therefore, the aim of this project was to investigate FATP1 and FATP4 protein expression in the vastus lateralis muscle from healthy human individuals and to what extent FATP1 and FATP4 protein expression were affected by an increased fuel demand induced by exercise training. Eight young healthy males were recruited to the study. All subjects were non smokers and did not participate in regular physical activity (<1 time per week for the past 6 months, VO2peak 3.4±0.1 l O2 min−1). Subjects underwent an 8 week supervised aerobic training program. Training induced an increase in VO2peak from 3.4±0.1 to 3.9±0.1 l min−1 and citrate synthase activity was increased from 53.7±2.5 to 80.8±3.7 µmol g−1 min−1. The protein content of FATP4 was increased by 33%, whereas FATP1 protein content was reduced by 20%. Interestingly, at the end of the training intervention a significant association (r2 = 0.74) between the observed increase in skeletal muscle FATP4 protein expression and lipid oxidation during a 120 min endurance exercise test was observed. In conclusion, based on the present findings it is suggested that FATP1 and FATP4 proteins perform different functional roles in handling LCFA in skeletal muscle with FATP4 apparently more important as a lipid transport protein directing lipids for lipid oxidation

A 1-Year Study of Endurance Runners: Training, Laboratory Tests, and Field Tests

Purpose: To compare critical speed (CS) measured from a single-visit field test of the distance–time relationship with the “traditional” treadmill time-to-exhaustion multivisit protocol. Methods: Ten male distance runners completed treadmill and field tests to calculate CS and the maximum distance performed above CS (D′). The field test involved 3 runs on a single visit to an outdoor athletics track over 3600, 2400, and 1200 m. Two field-test protocols were evaluated using either a 30-min recovery or a 60-min recovery between runs. The treadmill test involved runs to exhaustion at 100%, 105%, and 110% of velocity at VO2max, with 24 h recovery between runs. Results: There was no difference in CS measured with the treadmill and 30-min- and 60-minrecovery field tests (P .05). A typical error of the estimate of 0.14 m/s (95% confidence limits 0.09–0.26 m/s) was seen for CS and 88 m (95% confidence limits 60–169 m) for D′. A coefficient of variation of 0.4% (95% confidence limits: 0.3–0.8%) was found for repeat tests of CS and 13% (95% confidence limits 10–27%) for D′. Conclusion: The single-visit method provides a useful alternative for assessing CS in the field