Influence of a physical exercise until exhaustion in normothermic and hyperthermic conditions on serum, erythrocyte and urinary concentrations of magnesium and phosphorus

J Therm Biol. 2019 Feb:80:1-6. doi: 10.1016/j.jtherbio.2018.12.020. Epub 2018 Dec 25.

Abstract

Aim: The aim of this study was to evaluate the effect of the performance of a maximal exercise test until exhaustion in normothermic and hyperthermic conditions on body concentrations of magnesium (Mg) and phosphorus (P).

Methods: 19 adult males (age: 22.58 ± 1.05 years) performed two maximum incremental exercise tests on a cycloergometer separated by 48 h. The first was performed in normothermia (22 ± 2 °C) and the second in hyperthermic conditions induced with a sauna (42 ± 2 °C). Blood and urine samples were taken before and after each test.

Results: The tests in hyperthermia did not produce ergospirometric alterations or a noticeable cardiovascular drift. Serum Mg concentrations underwent a reduction after the stress test in hyperthermia (p > 0.05) but not in normothermia. Nevertheless, urinary and erythrocyte concentrations of Mg, and urinary, erythrocyte and serum concentrations of P did not undergo alterations in either conditions.

Conclusions: It seems that exercise in hyperthermic conditions induces a tissue redistribution of Mg in the body, a fact which was not observed in normothermic conditions.

Keywords: Erythrocyte; Heat stress; Magnesium; Phosphorus; Serum; Urine.

MeSH terms

  • Adult
  • Erythrocytes / physiology
  • Exercise / physiology*
  • Exercise Test
  • Fatigue / blood*
  • Fatigue / physiopathology
  • Fatigue / urine*
  • Hematocrit
  • Humans
  • Magnesium / urine
  • Male
  • Phosphorus / urine
  • Skin Temperature
  • Temperature
  • Young Adult

Substances

  • Phosphorus
  • Magnesium