Summary
The effects of the discontinuation (DET) of an endurance training/heat acclimation (T/A) program on vascular volumes were studied in 16 adult males. Resting and exercise blood volume dynamics were examined prior to and during an exercise task performed after completion of T/A (CT1) and again at the end of DET (CT2). T/A consisted of cycling at 60% of peak\(\dot V_{O_2 }\) for 90 min per day, 6 days per week, for 4 weeks. Ambient temperature was 20‡ C for the first 3 weeks and 40‡ C for the last week (rh=30–35%). Subjects were randomly assigned to one of the following DET conditions: 1) cycling one day per week at 40‡ C, 2) cycling one day per week at 20‡ C, 3) resting one day per week at 40‡ C, 4) control. The exercise tasks consisted of 60 min of continuous cycle ergometer exercise at 50% of peak\(\dot V_{O_2 }\) (Ta=30‡ C, rh=35%). Although significant differences were found between CT1 and CT2, there were no interactions between the various DET conditions. Resting red cell volume decreased 98 ml and plasma volume decreased 248 ml following DET. A reduction in plasma protein content accounted for 97% of the decrease in plasma volume. Hemoconcentration occurred during exercise in both CT1 and CT2, while there were slight increases in plasma [Na+] and [Cl−] and a rapid rise in [K+]. It appears that a single exercise and/or heat exposure per week was not different from complete cessation of endurance exercise in the heat with regard to maintenance of the various vascular volumes.
Similar content being viewed by others
References
Adam JM, Fox RH, Grimby G, Kidd DJ, Wolff HS (1960) Acclimatization to heat and its rate of decay in man. J Physiol (Lond) 152:26–27
Bass DE, Buskirk ER, Lampietro PF, Mager M (1958) Comparison of blood volumes during physical conditioning, heat acclimatization and sedentary living. J Appl Physiol 12:186–188
Bonner RM, Harrison MH, Hall CJ, Edwards RJ (1976) Effect of heat acclimatization on intravascular response to acute heat stress in man. J Appl Physiol 41:708–713
Brotherhood J, Rozovic B, Pugh L (1975) Hematological status of middle- and long-distance runners. Clin Sci Mol Med 48:139–145
Brynteson P, Sinning WE (1973) The effects of training frequencies on the retention of cardiovascular fitness. Med Sci Sports Exerc 5:29–33
Convertino VA, Greenleaf JE, Bernauer EM (1980) Role of thermal and exercise factors in the mechanism of hypervolemia. J Appl Physiol 48:657–664
Convertino VA, Keil LC, Greenleaf JE (1983) Plasma volume, renin, and vasopressin responses to graded exercise after training. J Appl Physiol 54:508–514
Coyle EF, Martin WH III, Sinacore DR, Joyner MJ, Hagberg JM, Holloszy JO (1984) Time course of loss of adaptations after stopping prolonged intense endurance training. J Appl Physiol 57:1857–1864
Dahms TE, Horvath SM (1974) Rapid, accurate technique for determination of carbon monoxide in blood. Clin Chem 20:533–537
Delanne R, Barnes JR, Brouha L (1958) Changes in concentration of plasma protein fractions during muscular work and recovery. J Appl Physiol 13:97–104
Dill DB, Costill DL (1974) Calculations of percentage changes in the volume of blood, red cells, and plasma in dehydration. J Appl Physiol 37:247–248
Dill DB, Hall FG, Hall KD, Dawson C, Newton JL (1966) Blood, plasma, and red cell volumes: age, exercise, and environment. J Appl Physiol 21:597–602
Fortney SM, Senay LC Jr (1979) Effect of training and heat acclimation on exercise responses of sedentary females. J Appl Physiol 47:978–984
Fournier M, Ricci J, Taylor AW, Ferguson RJ, Montpetit RR, Chaitman BR (1982) Skeletal muscle adaptation in adolescent boys: sprint and endurance training and detraining. Med Sci Sports Exerc 14:453–456
Greenleaf JE (1984) Physiological responses to prolonged bed rest and fluid immersion in humans. J Appl Physiol 57:619–633
Hagan RD, Diaz FJ, McMurray RG, Horvath SM (1980) Plasma volume changes related to posture and exercise. Proc Soc Exp Biol Med 165:155–160
Harrison MH (1985) Effects of thermal stress and exercise on blood volume in humans. Physiol Rev 65:149–209
Harrison MH, Edwards RJ, Graveney MJ, Cochrane LA, Davies JA (1981) Blood volume and plasma protein response to heat acclimation in humans. J Appl Physiol 50:597–604
Harrison MH, Edwards RJ, Leitch DR (1975) Effect of exercise and thermal stress on plasma volume. J Appl Physiol 39:925–931
Henriksson J, Reitman JS (1977) Time course changes in human skeletal muscle succinate dehydrogenase and cytochrome oxidase activities and maximal oxygen uptake with physical activity and inactivity. Acta Physiol Scand 99:91–97
Hickson RC, Kanakis C Jr, Davis JR, Moore AM, Rich S (1982) Reduced training duration effects on aerobic power, endurance, and cardiac growth. J Appl Physiol 53:225–229
Holmgren A, Mossfeldt F, Sjostrand T, Strom G (1960) Effect of training on work capacity, total hemoglobin, blood volume, heart volume, and pulse rate in recumbant and upright positions. Acta Physiol Scand 50:72–83
Kilburn KH (1966) Muscular origin of elevated plasma potassium during exercise. J Appl Physiol 21:675–678
Kjellberg SR, Rudhe V, Sjostrand T (1950) Increase in the amount of hemoglobin and blood volume in connection with physical training. Acta Physiol Scand 19:146–151
McMurray RG (1983) Plasma volume changes during submaximal swimming. Eur J Appl Physiol 51:347–356
Novosadova J (1977) The changes in hematocrit, hemoglobin, plasma volume and proteins during and after different types of exercise. Eur J Appl Physiol 35:223–230
Oscai LB, Williams BT, Hertig BA (1968) Effect of exercise on blood volume. J Appl Physiol 24:622–624
Scatchard G, Batchelder AC, Brown A (1944) Chemical, clinical and immunological studies on the products of human plasma fractionation. VI. The osmotic pressure of plasma and of serum albumin. J Clin Invest 23:458–464
Senay LC Jr (1978) Early response of plasma contents on exposure of working men to heat. J Appl Physiol 44:166–170
Senay LC Jr, Kok R (1977) Effects of training and heat acclimatization on blood plasma contents of exercising man. J Appl Physiol 43:591–599
Senay LC Jr, Pivarnik JM (1985) Fluid shifts during exercise. In: Terjung RL (ed) Exercise and sport sciences reviews. Macmillan, New York, pp 335–387
Senay LC Jr, Rogers G, Jooste P (1980) Changes in blood plasma during progressive treadmill and cycle exercise. J Appl Physiol 49:59–65
Smith EE, Guyton AC, Manning RD, and White RJ (1976) Integrated mechanisms of cardiovascular response and control during exercise in the normal human. Prog Cardiovasc Dis 18:421–443
Strydom NB, Kok R, Jooste PL, Van Der Walt WH (1975) Intermittent exposure to heat, and the retention of heat acclimatization. J South African Inst Mining Metallurgy 75:315–318
Van Beaumont W, Underkofler S, van Beaumont S (1981) Erythrocyte volume, plasma volume, and acid-base changes in exercise and heat dehydration. J Appl Physiol 50:1255–1262
Williams CG, Wyndham CH, Morrison JF (1967) Rate of loss of acclimatization in summer and winter. J Appl Physiol 22:21–26
Winer BJ (1971) Statistical principles in experimental design. McGraw-Hill, New York, 2 ed
Wyndham CH, Jacobs GE (1957) Loss of acclimatization after six days in cool conditions on the surface of a mine. J Appl Physiol 11:197–199
Author information
Authors and Affiliations
Additional information
This work was supported in part by the National Institutes of Health, under Grant H207050-09
Rights and permissions
About this article
Cite this article
Pivarnik, J.M., Senay, L.C. Effects of exercise detraining and deacclimation to the heat on plasma volume dynamics. Europ. J. Appl. Physiol. 55, 222–228 (1986). https://doi.org/10.1007/BF00715009
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00715009