Impact of Mild Dehydration and Subsequent Rehydration on Cellular Stress and Physiological Performance

Summary

Our goal is to determine whether hydration status influences inflammation, and overall physiological performance in adults aged 45-65. Aim 1: The effects of 4-day mild dehydration followed by 4-day rehydration (defined as approximately 2-3% body mass loss) on H2O2, upstream inflammatory signal (NFkB), mitochondrial fragmentation, and autophagy in circulating PBMCs. Aim 2: The effects of 4-day mild dehydration followed by 4-day rehydration (defined as approximately 2-3% body mass loss) on fasting glucose, sleep performance, and strength performance. Participant will: complete a 4-day hydration protocol, followed by a 4-day dehydration protocol, and then a 4-day rehydration protocol. attend five laboratory visits for testing: Day 1: Informed consent and familiarization Day 2: Pre-hydration testing (before the 4-day hydration protocol) Day 3: Pre-dehydration testing (before the dehyration protocol) Day 4: Post-dehydration testing (after the dehydration protocol) Day 5: Post-rehydration testing (after the rehydration protocol)

Eligibility

Age range

45–65 years

Sex

All

Healthy volunteers

Yes

Interventions

• Behavioral
  Hydration-Dehydration-Rehydration Protocol (HDR)

  The HDR Protocol is a 12-day, sequential fluid manipulation intervention designed to assess the physiological effects of controlled changes in hydration status. The protocol consists of three consecutive 4-day phases: Hydration Phase (Days 1-4): Participants follow a standardized fluid intake protocol designed to promote and maintain a euhydrated state. Hydration status is monitored using objective measures such as urine specific gravity and body mass. Dehydration Phase (Days 5-8): Participants adhere to a fluid-restriction regimen to induce a hypohydrated state. The level of dehydration is verified through the same hydration status measures to ensure consistent and safe hypohydration. Rehydration Phase (Days 9-12): Participants resume the standardized fluid intake protocol used during the Hydration Phase to restore euhydration. Rehydration effectiveness is confirmed through repeated hydration assessments.

Location