Impact of Mild Hypohydration on Muscle Endurance, Power, and Strength in Healthy, Active Older Men

Abstract

Goulet, EDB, Mélançon, MO, Lafrenière, D, Paquin, J, Maltais, M, and Morais, JA. Impact of mild hypohydration on muscle endurance, power, and strength in healthy, active older men. J Strength Cond Res 32(12): 3414-3424, 2018-Under particular circumstances older persons may be vulnerable to developing mild chronic hypohydration. In young adults, hypohydration has been shown to impair muscle endurance, power and strength. Muscle performance declines with aging, a condition known as dynapenia. How hypohydration impacts muscle performance in older persons remains unclear. In this study, we examined this question, believing it may identify a factor exacerbating dynapenia. One-hour after having been passively exposed to heat where either a body mass loss of 1% was induced or euhydration maintained with fluid ingestion, 8 healthy, active older men (age: 68 ± 5 years) completed an exercise testing session where indices of muscle strength (30-second chair stand, grip strength, maximal isometric seated leg-press extension), endurance (seated leg-curl flexion + seated leg-press extension to exhaustion at 60% of 1 repetition maximum), and power (30-second Wingate test) were assessed. Gastrointestinal temperature before exercise testing was not significantly different from that measured before heat exposure with neither hydration regimen. Magnitude-based inferential statistics indicate that from a clinical perspective, the effect of hypohydration on 30-second chair stand (-1.0 ± 4.4%) is possibly harmful, for grip strength (-2.4 ± 4.1%), lower limbs endurance (-7.5 ± 11.2%), and anaerobic power (-3.9 ± 4.3%) likely detrimental, and unclear with respect to maximal isometric lower limb strength. Maintaining adequate hydration in older men is important, since hypohydration of only 1% body mass could impede muscle endurance, power and strength and, consequently, worsen the impact of dynapenia.

Intracellular Water Content in Lean Mass is Associated with Muscle Strength, Functional Capacity, and Frailty in Community-Dwelling Elderly Individuals. A Cross-Sectional Study

“…In our opinion, among these factors, myocite hydration could play a relevant role. Our results also agree with those published by Goulet et al, who suggest that acute dehydration of 1% of body weight in healthy active 60 to 75 years old mencould affect muscle endurance, power and strength [25]. Moreover, the correlation between ICW and muscle strength has also been observed in young adult athletes [26], with some authors suggesting that cell volume is a metabolic signal that regulates cellular function and also that cellular swelling leads to anabolism and cellular shrinkage promotes catabolism and protein degradation [27,28].…”

Postural control and balance in a cohort of healthy people living in Europe

“…Interestingly, we identified worsening balance in elderly people, and these results are in line with those published in literature. [49–52] However, we also recorded altered balance in young age, probably due to a lack of muscle strength (dynapenia) that is present at this age. [53] Authors reported children's lack of key motor skills (strength, power, coordination) that are necessary components for the balance capacity [53–56] ; this provides us with a possible explanation of altered balance at early age.…”

The Role of Water Homeostasis in Muscle Function and Frailty: A Review

“…Muscular strength is determined by many factors and, in the elderly, it seems to be more related to the quality of the muscle and its ability to contract and generate strength than to the quantity of muscle. Few studies have evaluated the effect of intracellular hydration on muscle function in the elderly, but some authors have suggested that muscle intracellular hydration could be an indicator of muscle quality and contractile capacity [105,106,107,108]. Ritz reported an increase in ECW with ageing, especially among people with disabilities or altered health conditions [106].…”