Skip to main content

Table 2 Change in plasma volume, plasma sodium concentration, and thirst sensation

From: A comparison of hydration effect on body fluid and temperature regulation between Malaysian and Japanese males exercising at mild dehydration in humid heat

  Baseline   Exercise 5 min   Exercise 60 min   Recovery 30 min  
∆Plasma volume, %
 Japanese non-hydrated    -6.1 (0.8) ‡ -9.6 (1.2) ‡# -4.1 (0.8) ‡
 Japanese hydrated    -5.6 (0.9) ‡ -8.0 (1.0) ‡ -4.5 (0.8) ‡
 Malaysian non-hydrated    -5.2 (0.6) ‡ -7.8 (1.7) ‡ -3.6 (1.4) ‡
 Malaysian hydrated    -5.3 (0.5) ‡ -5.6 (1.7) †‡ -1.0 (1.5)
∆Sodium, mmol · L -1
 Japanese non-hydrated    1.5 (0.4) ‡ 1.9 (0.3) ‡ 1.4 (0.4) ‡
 Japanese hydrated    1.8 (0.3) ‡ 1.2 (0.4) -0.1 (0.4) †
 Malaysian non-hydrated    1.6 (0.4) ‡ 2.3 (0.3) ‡ 1.6 (0.5) ‡
 Malaysian hydrated    1.3 (0.3) ‡ 0.4 (0.2) † -1.3 (0.6) †‡
Thirst sensation
 Japanese non-hydrated 0.2 (0.1) 0.8 (0.2) 2.2 (0.1) 1.7 (0.2)
 Japanese hydrated 0.2 (0.1) 0.6 (0.1) 0.7 (0.3) † 0.5 (0.2) †
 Malaysian non-hydrated 0.0 (0.0) 0.5 (0.1) 1.4 (0.2) * 1.3 (0.2)
 Malaysian hydrated 0.2 (0.1) 0.4 (0.2) 0.1 (0.1) † 0.1 (0.1) †
  1. Values are the mean (SE). The percentage change in plasma volume and plasma sodium concentration was analyzed in 10 Japanese and 8 Malaysians. *Significant differences between Japanese and Malaysians in the non-hydrated condition. †Significant difference between the hydrated and non-hydrated condition in Japanese or Malaysians at the same time points. ‡Significantly different from baseline within a trial. #Significant difference between 5 min and 60 min after starting exercise.