Hydration status after exercise affect resting metabolic rate and heart rate variability

Nutr Hosp. 2014 Dec 17;31(3):1273-7. doi: 10.3305/nh.2015.31.3.8523.

Abstract
in English, Spanish

Introduction: Heart rate variability and resting metabolic rate are commonly to assess athlete's physiological status and energy requirements. Exercise-induced dehydration can reach up to 5% of body mass per hour. Consequently, dehydration may have a profound physiological effect on human's homeostasis.

Objectives: To compare the effects of dehydration and rehydration after exercise on heart rate variability and resting metabolic rate in college athletes.

Methods: 14 college athletes were divided into a dehydration group (n=7) and a rehydration group (n=7), both submitted to basal (T1) heart rate variability and resting metabolic rate measurements. After basal measurements both groups were actively dehydrated (-3.4 ± 0.4% of body mass for both groups). Afterwards, dehydration group rested, while rehydration group receive a fluid intake (during a 3 h period) equivalent to 150% of body mass loss achieved during active dehydration. Four hours after active dehydration heart rate variability and resting metabolic rate were re-assessed (T2).

Results: At T2 both rehydration group (+13%) and dehydration group (+30%) achieve a significant (p<0.05) increase in resting metabolic rate, however, only dehydration group ..showed a significant reduction in heart rate variability. More so, the change in resting metabolic rate was significantly higher in dehydration group compared to rehydration group.

Discussion: Hydric homeostasis after exercise affects resting metabolic rate and heart rate variability, highlighting the necessity to control hydration state before resting metabolic rate and heart rate variability assessment.

Introducción: La variabilidad del ritmo cardiaco y la tasa metabólica basal se utilizan en evaluaciones de deportistas. La deshidratación por ejercicio puede conducir a pérdidas de hasta 5% de la masa corporal. En consecuencia, la deshidratación produce un profundo efecto sobre la homeostasis humana. Objetivos: Comparar los efectos de la deshidratación y la rehidratación después del ejercicio en la variabilidad del ritmo cardíaco y la tasa metabólica basal. Métodos: 14 atletas universitarios fueron divididos en un grupo de deshidratación (n=7) y un grupo de rehidratación (n=7), ambos fueron sometidos mediciones basales (Tiempo 1) de variabilidad del ritmo cardíaco y tasa metabólica basal. Después de las mediciones basales, ambos grupos se deshidrataron activamente (-3,4 ± 0,4% masa corporal). Posteriormente, el grupo de deshidratación descansado, mientras que el grupo de rehidratación recibió agua equivalente al 150% de la masa pérdida. Cuatro horas después de la deshidratación se re-evaluó la variabilidad del ritmo cardíaco y tasa metabólica (Tiempo 2). Resultados: El grupo de rehidratación (+13%) y el de deshidratación (+30%) lograron un aumento significativo en la tasa metabólica basal (p.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Athletes*
  • Basal Metabolism / physiology*
  • Body Weight
  • Dehydration / etiology
  • Dehydration / physiopathology*
  • Dehydration / therapy
  • Exercise*
  • Fluid Therapy
  • Heart Rate / physiology*
  • Homeostasis
  • Humans
  • Male
  • Weight Loss
  • Young Adult