sweat_rate  sodium  potassium
  3.7  48.5   9.3
  5.7  65.1   8.0
  3.8  47.2  10.9
  3.2  53.2  12.0
  3.1  55.5   9.7
  4.6  36.1   7.9
  2.4  24.8  14.0
  7.2  33.1   7.6
  6.7  47.4   8.5
  5.4  54.1  11.3
  3.9  36.9  12.7
  4.5  58.8  12.3
  3.5  27.8   9.8
  4.5  40.2   8.4
  1.5  13.5  10.1
  8.5  56.4   7.1
  4.5  71.6   8.2
  6.5  52.8  10.9
  4.1  44.1  11.2
  5.5  40.9   9.4