Effect of Dehydration Combined with Inflammatory Response on Muscle Fluid Dynamics in Non-Exercise Muscle

Authors

Trinity N. Domonkos, Texas Tech UniversityFollow
Casey Appell, Texas Tech UniversityFollow
Karina Olvera, Texas Tech UniversityFollow
Sarah Walper, Texas Tech UniversityFollow
Christian Hoebelheinrich, Texas Tech UniversityFollow
Seth Bernardino, Texas Tech UniversityFollow
Amar Vaela, Texas Tech UniversityFollow
Jalyn Dunlap, Texas Tech UniversityFollow
Larry Munger, Texas Tech University Health Sciences CenterFollow
Hui-Ying Luk, Texas Tech UniversityFollow

Abstract

Water comprises approximately 40% of muscle mass, and intracellular fluid shifts occur in response to osmotic gradients between intracellular and extracellular (e.g., blood) compartments. Fluid also enters injured muscle during inflammation, resulting a temporary increase in muscle cross sectional area (mCSA). Dehydration elevates blood osmolality, and fluid enters damaged tissue. However, it remains unclear if dehydration-induced osmotic stress and swelling from muscle damage can influence fluid dynamics (fluid retention) in non-damaged muscle. PURPOSE: To determine whether hydration status and damage-related swelling alter fluid retention in the contralateral non-damaged leg. METHODS: Six recreationally active men (age: 20±3 yrs, height: 173.6±8.1 cm, weight: 79.9±12.2 kg, lean mass: 58.6±13.0 kg, body fat percent: 28.3±6.5%) completed two identical bouts of unilateral maximal knee extension exercise consisted of 10 sets of 30 repetitions (EXE) in a euhydrated state then underwent a 3-d recovery period either under the EUHY or DEHY conditions. During the 3-d recovery participants consumed >3.7 L/d of fluid in the EUHY condition. For DEHY, participants did not consume any fluid for the first 24 hours and consumed 1.5 L/d of fluid for the subsequent 48 hours. Ultrasound images of the rectus femoris (RF) of the non-damage leg were taken at before (PRE), and 24hr, 48hr, and 72hr after EXE. The mCSA was assessed via ImageJ. RESULTS: No significant differences were observed; however, trends toward the main effects of condition (p=0.083, hp2 = 0.482) and time (p=0.096, hp2 = 0.335) were observed for the mCSA of the non-damaged RF (0.207±0.96; p=0.083, d= 0.482). In DEHY, mCSA was trended towards smaller than EUHY (p=0.083, d=0.482). In addition, mCSA decreased from PRE to 48hr (0.211±0.091; p=0.069, d = 0.335) and from 24hr to 48hr (0.312±0.134; p=0.067, d = 0.335). CONCLUSION: A trend in the data suggests that dehydration may reduce intramuscular fluid in the non-damage leg. Dehydration-induced osmotic stress, combined with inflammatory response, may promote fluid efflux from the contralateral non-damaged leg, reflecting whole-body fluid redistribution rather than a purely local response to muscle damage.

Recommended Citation

Domonkos, Trinity N.; Appell, Casey; Olvera, Karina; Walper, Sarah; Hoebelheinrich, Christian; Bernardino, Seth; Vaela, Amar; Dunlap, Jalyn; Munger, Larry; and Luk, Hui-Ying (2026) "Effect of Dehydration Combined with Inflammatory Response on Muscle Fluid Dynamics in Non-Exercise Muscle," International Journal of Exercise Science: Conference Proceedings: Vol. 2: Iss. 18, Article 144.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss18/144