european college of sport science

Friday, June 26th, 2009
08:30 - 10:00
Oral presentations
OP-PH08 Physiology 8
EFFECT OF DIFFERENT LOCAL COOLING APPLICATIONS ON THE ENDURANCE CAPACITY DURING CYCLING
HOHENAUER, E., CLIJSEN, R., CABRI, J., CLARYS, P.
UNIVERSITY COLLEGE PHYSIOTHERAPY
Hohenauer, E.1, Clijsen, R.1, Cabri, J.2, Clarys, P.3
1: University College TVDL (Landquart, Switzerland), 2: FMH-UTL (Lisbon, Portugal), 3: VUB (Brussel, Belgium)
INTRODUCTION: The production of heat during intense exercise causes an increase of muscle temperature and core temperature, which
can amount up to 40°C. In order to avoid losing endurance capacity, the body adjusts by rapidly reducing temperature. Evaporation is
the primary mechanism by which muscle heat is released during exercise (Nybo et al., 2007).
AIM: The aim of this study was to investigate the effects of local upper arms cooling, upper body cooling and combined cooling of the
upper arms and upper body on the endurance capacity during cycling.
METHODS: Seven male young healthy subjects (n=7) volunteered in this study. A random, cross-over design was used. The subjects were
tested under four different conditions: A= without cooling; B= Energicer cooling bands; C= Energicer cooling vest; D= Energicer cooling
bands and vest. The cooling bands (7.5 x 5 x 0.5 cm) were placed on the left and right upper arm. Both vest and bands were saturated
(bands 25ml each, vest 225ml) with a menthol-alcohol liquid (Liquid Ice Cosmedicals GmbH, Unterägeri, Switzerland). We conducted a
standardized incremental bike ergometer test following the Swiss Olympic Guidelines. Time to exhaustion was determined and used as
the independent variable for endurance capacity. At the end of each incremental step following variables were measured: blood lactate,
heart rate, body temperature and perceived exhaustion (BORG scale).The 4 experiments were accomplished within one week to decrease
the chance of adaptation. Environmental temperature (35°C) and relative humidity (44%) of the lab were kept constant.
RESULTS: Mean age and BMI of the subjects were 39,11 y and
28,2 kg.m-2 respectively. Mean time to exhaustion didn’t differ between the four conditions (p>0,05). We observed no significant differences
at blood lactate, heart rate and body temperature during examination between the four conditions.
DISCUSSION: Our results are in line with Duffield et al. (2003). However all participants mentioned to feel more comfortable when wearing
the cooling vest under the used environmental conditions. This effect might aggravate with the airflow when cycling under outdoor conditions
which may lead to psychological advantages for the athlete. We didn’t observe any significant changes in body temperature, and
endurance capacity if cooling bands and/or cooling vests were used.
CONCLUSION: Under hot and humid environmental conditions local cooling of the upper arms and/or upper body by Energicer bands
and/or vests don’t enhance endurance capacity during cycling. Further studies are needed to analyse the effects of Energicer bands and
vests when simulating the airflow in hot and humid environmental conditions and the effects on the skin temperature.
REFERENCES: Duffield R, Dawson B, Bishop D, Fitzsimons M, Lawrence S. (2003). Br J Sports Med, 37:164-169.
Nybo L. (2007). J App. Physiol, 104:871-878.
THE EFFECT OF REPETITIVE COOLING ON PRECOOLING EFFICIENCY AND EXERCISE PERFORMANCE: A PILOT STUDY
KOCJAN, N., SCHATTI, O., BOGERD, C.P., ROSSI, R.M.
EMPA, SWISS FEDERAL LABORATORIES FOR MATERIALS TESTING AND RESEARCH
Introduction: It is known that repetitive cold exposure improves thermal sensation and, decreases skin and body core temperatures (1, 2).
Such responses could potentially improve precooling efficiency, defined as the ease with which body heat storage is reduced. Up to now,
no studies have been published on the effect of repetitive cooling on precooling efficiency and, subsequent exercise performance. Therefore,
we aimed at investigating: i) if repetitive cooling increases the efficiency of precooling and, ii) how such response affects various
thermophysiological parameters during exercise in hot and humid ambient.
Methods: Four physically fit men with an average (SD) VO2peak of 65.4 (4.1) ml/min/kg participated in this study. They reported to the
laboratory for 10 consecutive days. Each time, the subjects were submitted to 1 hour of cooling with an ice vest (Arctic Heat, Burleigh
Heads, QLD, Australia) while sitting at an ambient temperature (Ta) of 20.2 (0.2) °C. On the 1st and the 10th day, this was followed by 25
min of cycling exercise at 60% subject’s VO2peak in Ta of 30.2 (0.1) °C and relative humidity of 71.4 (0.8)%. On the 1st and the 10th day,
during cooling and exercise, body core temperature (Tc) and skin temperatures on eight body locations (Tsk), were registered every 10 s.
In addition, during the first and the last 5 min of cooling, skin blood flow (SkBF) was measured on forearm. While, rating of thermal perception
(TP) was noted each 15 min.
Results: On the 10th, compared with the 1st cooling day, SkBF increased for 80 (49) %. Where, such response indicates a decrease in
vasoconstrictor response. Cooling decreased Tsk on both occasions to a similar extend (1st day: 27.62 (1.30) °C; 10th day: 27.72 (1.11) °C).
However, on the 10th day the time to reach this value halved. Despite, Tc was before the start of cooling slightly higher on the 10th day, at
end of cooling, a similar Tc was reached. This was observed due to enhanced decrease of Tc on the 10th day. On average, TP improved
from -2.3 (1.3) on the 1st day, to -1.3 (1.0) on the 10th day. Finally, during subsequent exercise there were no apparent differences between
the 1st and the 10th cooling day in any of the variables investigated.
Conclusion
It is suggested that 10 days of consecutive cooling, when using an ice vest, can improve the efficiency of precooling. In particular, this is
ascribed to reduced vasoconstrictor response. Repetitive cooling does not affect any of the investigated thermophysiological parameters
during subsequent exercise performance in warm and humid ambient.
1. Leppaluoto J, Korhonen I, and Hassi J. Habituation of thermal sensations, skin temperatures, and norepinephrine in men exposed to
cold air. J Appl Physiol 90: 1211-1218, 2001.
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