Research

Mixed

Exercise-induced dehydration (approx. 3.5% body mass loss) significantly increases Resting Metabolic Rate (RMR) and reduces Heart Rate Variability (HRV) compared to rehydration, indicating that hydration status must be controlled for accurate physiological assessment.

If you are tracking your recovery using Heart Rate Variability (HRV) or Resting Metabolic Rate (RMR), you must be fully hydrated. Dehydration artificially lowers HRV (making you look overtrained) and raises RMR (skewing energy expenditure data). Ensure you are euhydrated before any physiological assessment to get accurate baselines.

ModerateSupportsMEDIUM confidence
At T2 the only significant (p<0.05) change observed in RG was an increase in RMR (+13%). On the other side, DG showed a significant (p<0.05) change in ... RMR (+30%) ... More so, the baseline to T2 change in ... RMR in DG is significantly higher compared with that of the RG.
Mauricio Castro‐Sepúlveda et al. · PubMed · 2014

Why this rating

Small sample size (n=14) and short duration (4h post-exercise), but controlled protocol.

Source

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

Mauricio Castro‐Sepúlveda et al. · PubMed · 2014

DOI 10.3305/nh.2015.31.3.8523

crossover · n=14Cited 37×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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