INTRODUCTION:-
Running is said to be the best form of exercise as it can be easily performed There are an estimated five to eight million individuals participating in running events globally. A 50% increase in participation in running has been tracked over the last decade. This growth has partly been driven by increased participation in Asia. In tropical warm, hot environments, the evaporation of sweat may be compromised, leading to lower rates of body heat dissipation Thus, it is reasonable to suggest that appropriate hydration maybe even more important for endurance running especially in tropical countries.
The human body is around 60% water. As a person acquires more lean muscle mass, their water percentage actually increases, which highlights the importance of proper hydration to maintain optimal performance. Water is incredibly important, especially for the brain, heart, and muscles.
A general rule of thumb for the recommended water intake for athletes is to start by calculating daily water needs. It’s usually recommended to drink half their body weight in ounces of water or other noncaloric beverages per day.
Here are some ways that hydration impacts the body
- Provides moisture to the eyes, nose, and mouth.
- Assists the body in thermoregulation through sweat.
- Transports nutrients, oxygen, and waste through the blood (yes hydration is important for your gut.
- Helps with the absorption of carbohydrates.
- Replenishes the muscle stores, as muscles are 75% water
- Helps with mental clarity and focus.
- Minimizes fatigue, which can help minimize the risk of marathon bonking.
DIFFERENT SUPPLEMENTS THAT CAN BE DISTANCE RUNNERS
The term “supplements’ includes products that address a distance athlete’s nutrition goals in a specialized context: medical supplements used to prevent/treat a nutrient deficiency (e.g., vitamin D or iron supplements); sports foods providing energy, macronutrients, and fluid requirements in scenarios where whole foods are impractical; and performance supplements that directly improve training or competition outcomes. Characteristics of these products and scenarios in which they contribute to a distance athlete’s nutrition plan are summarized elsewhere (Castell et al., 2019; Maughan et al., 2018; Peeling et al., 2019). The specific needs of long-distance races raise potential new uses of sports foods and performance supplements, based on the specific physiological, biochemical, and central nervous system factors that limit performance in these races, as well as the opportunity to consume products within the event, at least for races of half marathon and longer.
Eu-hydration is typically maintained over the course of day-to-day life through systemic alteration and biological controls . However, exercise during excess heat conditions can cause an acute disruption to fluid balance, challenging the athlete’s goal of optimal performance and safety during exercise, especially in hot environmental conditions. The process of fluid deficit is known as dehydration, while the outcome is defined as hypohydration. The loss of body water during exercise exacerbates physiological and perceptual strain and it is well established that these changes can impair endurance performance, particularly in hot environments and may increase the risk of exertional heat illness
Exercising in the cold, or at high altitudes merits special considerations when determining the fluid needs of athletes. Athletes must also be vigilant and mindful of their fluid needs during exercise in the cold. Exercise in the cold can still produce copious sweating, especially when heavy clothing is worn, while also diminishing thirst sensitivity and reducing ad libitum fluid consumption, thus potentially leading to impaired fluid replacement and hypohydration [12,23]. If possible, athletes should know their individual fluid replacement needs, based upon sweat rate measurement, during exercise in hot and cold environments to ensure they can develop a plan for competing while optimally hydrated.
Prerace hyperhydration (for review, see van Rosendal & Coombes, 2013; Goulet et al., 2007).
Mechanism of action
Fluid retention achieved by the use of an osmotic agent (glycerol or sodium) in fluids consumed in the hours before exercise increases body fluid stores; allows greater sweat losses during exercise to occur before the net fluid deficit becomes physiologically significant and impairs performance
Best practice protocol
25 ml/kg of fluid consumed ∼2-hr pre-exercise with ∼1-g/kg glycerol or 7-g sodium chloride; typically aids in the short-term retention of ∼600-ml fluid to add to body water stores
Ice slurry for precooling and within race cooling (for review, see Jay & Morris, 2018; Ross et al., 2013
Mechanism of action
Internal heat transfer from cold drink or the enthalpy of fusion of ice (phase change from solid to liquid) may reduce total body heat content and allow greater duration or intensity of exercise before thermoregulatory challenges become significant and impair performance
Best practice protocol
Ice slurry: ∼14-ml/kg of fluid consumed in two servings in the 30–60 min pre-exercise (i.e., immediately before abbreviated race warm-up) to allow time to excrete excess fluid if needed. Should be combined with external cooling strategies (e.g., cold-water immersion or ice
Ice slurry for precooling and within race cooling (for review, see Jay & Morris, 2018; Ross et al., 2013)
Mechanism of action
Internal heat transfer from cold drink or the enthalpy of fusion of ice (phase change from solid to liquid) may reduce total body heat content and allow greater duration or intensity of exercise before thermoregulatory challenges become significant and impair performance
Best practice protocol
Ice slurry: ∼14-ml/kg of fluid consumed in two servings in the 30–60 min pre-exercise (i.e., immediately before abbreviated race warm-up) to allow time to excrete excess fluid if needed. Should be combined with external cooling strategies (e.g., cold-water immersion or ice towels/vest) to provide additional effects, which might be continued during/after warm-up
CONCLUSION:
The most successful runners, during major city marathons, drink fluids ad libitum for less than approximately 60 seconds at a fluid ingestion rate of 0.55 ± 0.34 L/h and comparable to the current ACSM recommendations of 0.4-0.8 L/h. Nevertheless, these elite runners do not seem to maintain their BM within current recommended ranges of 2%-3%.
Slower runners plan to drink larger volumes compared with their faster counterparts. Both slower and first-time marathoners significantly lacked understanding of EAH. These groups have plans and knowledge that may put them at higher risk for developing EAH. Most marathon runners did not know of the guidelines to “drink to thirst,” suggesting the 2015 EAH Consensus statement may not have had the desired impact.
References:
Burke LM, Jeukendrup AE, Jones AM, Mooses M. Contemporary Nutrition Strategies to Optimize Performance in Distance Runners and Race Walkers. Int J Sport Nutr Exerc Metab. 2019 Mar 1;29(2):117-129. doi: 10.1123/ijsnem.2019-0004. Epub 2019 Apr 4. PMID: 30747558.
Saengsirisuwan V, Rollo I, Randell RK, Nithitsuttibuta K, Sainiyom P, Leow CHW, Lee JKW. Hydration Status, Fluid Intake, Sweat Rate, and Sweat Sodium Concentration in Recreational Tropical Native Runners. Nutrients. 2021 Apr 20;13(4):1374. doi: 10.3390/nu13041374. PMID: 33923890; PMCID: PMC8072971.
Beis, Lukas Y.*; Wright-Whyte, Moray BSc*; Fudge, Barry PhD†; Noakes, Timothy MD, PhD‡; Pitsiladis, Yannis P. PhD*. Drinking Behaviors of Elite Male Runners During Marathon Competition. Clinical Journal of Sport Medicine 22(3):p 254-261, May 2012. | DOI: 10.1097/JSM.0b013e31824a55d7
Namineni, Neeharika MD*; Potok, O. Alison MD†; Ix, Joachim H. MD†; Ginsberg, Charles MD†; Negoianu, Dan MD‡; Rifkin, Dena E. MD†; Garimella, Pranav S. MD, MPH†. Marathon Runners’ Knowledge and Strategies for Hydration. Clinical Journal of Sport Medicine 32(5):p 517-522, September 2022. | DOI: 10.1097/JSM.00000000