european college of sport science

Thursday, June 25th, 2009
COMPARISON OF SLEEP BETWEEN ATHLETES RUNNING SEVEN MARATHONS ON SEVEN CONTINENTS IN SEVEN DAYS
(7MM)
GAMBLE, D., GLASGOW, P., JENNINGS, D., MADIGAN, S., WEBB, M.
SPORTS INSTITUTE NORTHERN IRELAND
The completion of seven marathons, on seven continents, in seven consecutive days involved circumnavigating the globe, travelling more
than 35,000 miles, through 24 different time zones and required substantial physical and psychological endurance. Intercontinental
travel results in the disruption of normal circadian rhythms and is associated with fatigue and a range of symptoms, commonly referred
to as jet lag. Disturbance in the sleep-wake cycle is of particular concern as appropriate sleep is vital to promote the recovery process
post-exercise and facilitate subsequent physical performance. Exposure to day light is required to facilitate re-entrainment of circadian
rhythms. Thus the disruption in sleep may be exacerbated in a visually impaired (VI) athlete.
PURPOSE: To compare the quantity of sleep achieved between a VI athlete and his guide (N) runner during an extreme endurance challenge.
METHODS: Sleep was possible during the 63 h and 40 min of total flight-time and 19 h 20 min of hotel visits. Sleep was measured using a
body monitoring device, which was placed on the right tricep of each runner throughout the duration of the challenge. A classification
algorithm incorporating structured statistical measures from aggregated observations was used to detect sleep. This involved evaluation
of instantaneous agitation and sequences of motion, differential and proportional changes in heat-flux and skin temperature, the galvanic
skin response and the proximity to motion signatures. Comparisons in the quantity of sleep obtained between each marathon were
made using a one-way ANOVA.
RESULTS: The mean quantity of sleep achieved was 3 h 20 min + 1 h 23 min (range 1 h 0 min – 4 h 45 min) vs 5 h 27 min + 2 h 18 min
(range 2 h 26 min – 7 h 26 min) for the VI and N runner, respectively. There was a subsequent difference in the total amount of sleep
achieved, 19 h 58 min (VI) compared to 32 h 41 min (N). Although there was evidence of a disparity in the quantity of sleep achieved, this
difference was not significant (P>0.05).
CONCLUSION: This study indicates that the VI athlete experienced greater difficulty initiating and maintaining sleep throughout this extreme
challenge. This information may be relevant for practitioners developing preparation strategies for visually impaired athletes requiring
travel through multiple time zones to competition venues.
COMPARISON OF VO2 KINETICS IN WALKING AND RUNNING AT THE ‘ENERGETICALLY OPTIMAL’ GAIT TRANSITION
SPEED
SENTIJA, D.
FACULTY OF KINESIOLOGY, UNIVERSITY OF ZAGREB
Background: The metabolic costs for walking and running intersect at a speed (termed the energetically optimal transition speed, EOTS)
that is significantly higher than the preferred gait transition speed (Hreljac 1993; Brisswalter and Mottet 1996; Tseh et al. 2002). None of
the studies to date, considered the influence of a slow component of VO2 kinetics for walking and running in the determination of EOTS.
Purpose: The aim of this study was to examine VO2 kinetics during walking and running at the energetically optimal gait transition speed
(EOTS).
Methods: Twenty-two physical education students (21.4±2.4y, 182±7cm), performed three incremental treadmill tests for determination of
EOTS, the aerobic gas exchange thresholds (for walking, ATw, and running, ATr) and VO2max. Thereafter, they completed two squarewave
30-minute walking (W30) and running (R30) tests at the EOTS; VO2 was determined breath-by-breath, and computorised non-linear
regression techniques were used to describe either a mono-, bi- exponential or exponential+linear VO2 response. ANOVA for repeated
measurements was used to test for differences between walking and running parameters.
Results: The VO2 and speed of locomotion at the EOTS were 32.8 ml/kg and 8.2±0.2 km/h, respectively. Four subjects had to discontinue
the W30 test before completion, due to fatigue and pain in the shins. All W30 tests were distributed within the heavy and very heavy
intensity domains, while all R30 tests were distributed within the moderate and heavy intensity domains. The time constant for the fast
VO2 component (tau1) in the 30-minute tests was significantly smaller for running than for walking (29.0±9.1 s vs 33.7±9.8 s, p