/ Polar () 40% 60% 22 35( 50% RH) ± ( ) ( ) The Influence of Environmental Temperature and Exercise Intensity on Skin Blood Flow ABSTRACT Skin blood flow is the major system to modulate human temperature. Hyperthermia will interfere the hemostasis and result in local fatigue. Dynamic exercise also will cause a serious of cardiovascular regulation. These reactions mainly for maintain proper muscle perfusion and blood pressure. Consideration of the specific weather in Taiwan, it is meaningful to examine the influence of 1
different environment temperature and exercise intensity on skin blood flow. Ten healthy college male students were recruited as subjects. Skin blood flow was measured by a Laser Doppler flowmetry on forearm and thigh. Cortex MetaMax and Polar heart monitor were used to measured subjects. Environment temperature was under control at 22and 34by Walk-in Chamber. Exercise intensity was set at 40% and 60%, which according to the regression formula derive from. Repeated-measure MANOVA was used to analyze the difference between each testing condition. Results showed that: (1) In the early stage of exercise testing, the skin blood flow was significantly higher in hot environment temperature that in neutral environment temperature. (2) In the late stage, the skin blood flow was significantly higher in hot environment temperature & high exercise intensity that in neutral environment temperature & normal exercise intensity. (3) The tendency of changing in forearm and thigh skin blood flow was dissimilar during dynamic exercise. The skin blood flow seemed to attenuate when approach the exhaustion. It is concluded that environment temperature will significant influence the skin blood flow in the early stage of exercise. But in the later stage of exercise, exercise intensity is the mainly factor to influence the skin blood flow. The difference of raise-margin indicted that forearm skin blood flow play more remarkable action to moderate human temperature. Key Words: Environmental Temperature, Exercise Intensity, Skin Blood Flow : ;. (conduction & convection) (Alexander,1992) (core temperature) (SkBF) (hemostasis) (blood flow redistribution) (fluid & electrolyte redistribution) (CNS dysfunction) (uncoupling of oxidative phosphorylation)(brooks, 1984) : : 2
, (dynamic exercise) (circulatory response) (local muscle vasodilation) (cardio output, CO) (muscle perfusion) ( ) (Laser-FLO, BMP II,Vasomedic, ) (right angle Doppler probe, P-430 ) BIOPAC MP100 AcqKnowledge 3.7 ( ) AcqKnowledge 3.7 3
(Walk-in Chamber, TABIA EBL-8, ) 22 35( 50% RH) (22 34) (40%V02peak 60%V02peak) (Ledo ergometer, Excalibur with WLP, ) (Cortex MetaMax) Polar 30 (W) 60 0-2, 2-4, 4-6, 6-8 30W, 60W, 90W, 120W (all out) 60 1. 2. 1.10 3. (220- )±10 / 4. Borg (Borg 10-point scale)8 9 Ledo ± (repeated-measures MANOVA) α=0.05 T15~T25 (p<0.05) T0~T15 (34) (24) (p<0.05) T20~T30 (60%) 4
(40%) (p<0.05) 40% (22) 60% 40% (34) 60% T0 1.37±0.51 1.41±0.52 3.14±1.60 3.27±0.92 > T3 1.93±0.66 2.40±1.05 4.66±1.25 4.93±1.87 > T5 2.45±1.10 3.25±1.69 6.05±1.90 6.72±1.89 > T10 3.61±1.71 5.77±2.81 7.94±2.02 8.60±1.81 > T15 5.21±2.45 7.99±3.16 8.76±1.93 8.72±2.18 > T20 6.22±3.27 9.79±2.18 8.27±1.58 8.65±1.89 60%>40% T25 7.08±3.69 10.27±2.12 8.42±2.04 9.11±1.37 60%>40% T30 7.87±3.89 10.84±2.21 9.06±2.18 9.70±1.24 60%>40% T0 T3 T5 ml/min/100g > 60%>40% 12 10 8 6 4 2 0 T0 T3 T5 T10 T15 T20 T25 T30 ( ) T0~T30 5
T0~T5 (34) (24 ) (p<0.05) T10 (34) (60%) (p<0.05) T15~T20 (60%) (40%) (p<0.05) 40% (22) 60% 40% (34) 60% T0 0.73±0.30 1.00±0.46 2.66±1.20 2.22±1.07 > T3 5.00±2.19 5.88±1.76 7.32±1.32 7.29±3.14 > T5 5.34±2.09 6.04±1.87 8.53±2.53 8.47±3.66 > T10 5.88±2.21 7.86±2.30 8.62±3.14 10.83±3.11 > 60%>40% T15 6.74±2.70 9.82±4.47 9.37±3.29 10.79±2.91 60%>40% T20 7.77±2.97 10.43±4.13 9.28±3.13 10.72±2.46 60%>40% T25 8.44±3.29 10.79±4.66 8.98±2.89 10.65±2.65 T30 8.73±3.33 11.02±4.65 9.37±3.00 11.21±2.66 T0 T3 T5 ml/min/100g 12 10 8 6 4 2 0 > 60%>40% T0 T3 T5 T10 T15 T20 T25 T30 ( ) 6
: ( ), ( & ) ; 60%V02peak 40%V02peak ; 60%V02peak 40%V02peak ; 60%V02peak 40%V02peak ; : 60%V02peak> 40%V02peak> 60%V02peak> 40%V02peak :1. 2. (, 85), (Guyton, 1992) (Taylor, 1988; Patterson, 1994) 60%V02peak 40%V02peak (Nielson, l990) 7
(arterioles) (Brengelmann et al., 1977; Smolander et al., 1987) Taylor (1984) (36, 38, 40 42) Taylor (1988)Patterson (1994) Smolander, Saalo & Korhonen(1991) (50, 60, 70, 80, & 90% VO2max) (90% VO2max) (Vroman, Buskirk, & Hodgson, 1983) Nishiyasu (1992)13 Nishiyasu (1992) (pooling) Hirata (1989)8 20 89% Hirata (1989) Nishiyasu (1992) 40% Fortney (1984) 8
Smolander (1987) (cutaneous vasoconstriction) Taylor (1988) 125W (autaneous vascular conductance) (120~150W) Wassermann(1973) ( ) Nade1(1979) Skinner(1980) (85) 39 98-105. Alexander, P. S. & Mason, B. E. (1992). Human Anatomy and Physiology. Champaign, IL: Human Kinetics. Brooks, G. A. & Fahey, T. D. (1984). Exercise Physiology: Human Bioenergetics and its applications. New York, Macmillan. Fortney, S. M. (1984). Effect of hyperosmolarity on control of blood flow and sweating. Journal of Applied Physiology, 57, 1668-1673. Hirata, K., Nagasaka, T., & Noda, Y. (1989). Venous return form distal regions 9
affects heat loss from the arms and legs during exercise-induced thermal loads. European Journal of Applied Physiology, 58, 865-872. Nadel, E. R. (1979). Circulatory regulation during exercise in different ambient temperatures. Journal of Applied Physiology, 46, 430-437. Nielson, B. (l990). Solar heat load: Heat balance during exercise in closed subjects. European Journal of Applied Physiology, 60, 452-456. Nishiyasu, T., Shi, X., Gillen, c. M., Mack, G. W., & Nadel, E. R. (1992). Comparison of the forearm and calf blood flow response to thermal stress during dynamic exercise. Medicine and Science in Sports and Exercise, 24, 213-217. Patterson, M. J., Warlters, d., & Taylor, N. a. S. (1994). Attenuation of the cutaneous blood flow response during combined exercise and heat stress. European Journal of Applied Physiology, 69, 367-369. Skinner, J. D. & McLellan, T. H. (1980). The transition from aerobic to a anaerobic metabolism. Research Quarterly for Exercise and Sports, 51, 234-248. Smolander, J., Asslo J., & Korhonen, O. (1991). Effect of work load on cutaneous vascular response to exercise. Journal of Applied Physiology, 71, 1614-1619. Smolander, J., Kolari, P., Korhonen, O., & Ilmarinen, R. (1987).Skin blood flow during incremental exercise in a thermoneutral and a hot dry environment. European Journal of Applied Physiology, 56, 273-280. Taylor, W. F., Johnson, J. M., O leary d. S., & Park M. K. (1984). Modification fo the cutaneous vascular response to exercise by local skin temperature. Journal of Applied Physiology, 57, 1878-1884. Taylor, W. F., Johson, J. M., Kosiba, W. A., & Kwan. C. M. (1988). Graded cutaneous vascular responses to dynamic legexercise. Journal of Applied Physiology, 64, 1803-1809. Vroman, N. B., Buskirk, E. R., and Hodgson, J. L. (1983). Cardiac Output and Skin Blood Flow in Lean and Obese individuals during exercise in the heat. Journal of Applied Physiology, 55, 69-74. Wassermann, K., Whipp, B. J., Koyal, S. N., & Beaver, W. L. (1973). Anaerobic threshold and respiratory gas exchange during exercise. Journal of Applied Physiology, 35, 236-243. 10