Hydration for Gymnasts: What the Science Actually Says

Most gymnasts at a competition are already dehydrated before they compete. Not because they forgot to drink water that morning, but because they've been mildly dehydrated since the night before, and nobody noticed because nobody was looking. Research consistently finds that the majority of youth athletes arrive at competition in a state of underhydration.¹ In a sport where reaction time, focus, and physical output all decline with dehydration of just 1–2% of body weight, this is not a minor issue.

This guide covers the hydration science that actually applies to competitive gymnastics — how much gymnasts need, when they need it, what the research says about sports drinks versus water, and the practical strategies that keep performance intact across a full competition day.

How Common Is Dehydration in Young Athletes?

Dehydration among youth athletes before exercise begins is more prevalent than many parents and coaches expect. A 2025 systematic review published in the journal Nutrients, analyzing 51 studies on children and adolescents, found that among competitive young athletes, 81% of studies reported dehydration, while 69% of studies observed dehydration in non-athlete children, with biomarkers consistently indicating failure to meet recommended hydration guidelines in both groups.

Earlier research cited in Today's Dietitian similarly reported that 50% to 75% of child and adolescent athletes were already dehydrated before beginning sports practice and competition. These figures suggest that arriving at a gymnastics practice or competition already in a mild state of dehydration is common rather than exceptional.

Why Dehydration Matters for Performance

The physiological effects of dehydration are well documented in the sports science literature. Even a small amount of dehydration, as little as 1% of body weight — can increase cardiovascular strain as indicated by a disproportionate elevation of heart rate. Research published in Medicine & Science in Sports & Exercise found that for every 1% loss in body mass due to dehydration, heart rate increases by an average of 3 beats per minute.

In children specifically, the threshold at which performance is affected may be lower than in adults. In children, the negative effects of dehydration on performance may occur sooner than in adults — occurring with as little as a 1% decrease in body weight.

Cognitive performance is also affected. Research cited by the Gatorade Sports Science Institute found that simple methods for estimating hydration needs and status in youth athletes by athletes and their parents, coaches, and athletic training and medical support teams remain acceptable estimation standards, noting the complexity of monitoring hydration in a growing population.

Fluid Needs: What the AAP Recommends

The American Academy of Pediatrics (AAP) has published specific hydration guidelines for children and adolescents engaged in sports. These are the figures most widely cited by pediatric sports medicine practitioners in the United States.

According to the AAP policy statement on heat stress and exercise, referenced in the National Athletic Trainers' Association (NATA) guide on healthy hydration for young athletes, practitioners are advised to provide and promote consumption of readily accessible fluids at regular intervals before, during, and after activity to offset sweat loss and maintain adequate hydration.

The AAP's specific per-exercise fluid intake guidance, as cited in the Policy Statement of the Council on Sports Medicine and Fitness and summarized by registered dietitian Kelly Jones MS, RD, CSSD, is as follows:

The AAP also publishes baseline daily fluid targets. The AAP recommends that children aged 1 to 3 years old need about 4 cups of fluid per day, children 4 to 8 years of age need about 5 cups of fluid per day, and children aged 9 and older need about 7 to 8 cups of fluid per day. These figures represent minimum daily totals and do not account for additional fluid losses from sports activity.

These are general guidelines. Actual fluid intake amounts should be individualized depending on environmental conditions and physical-activity levels.

The ACSM Position on Fluid Replacement in Exercise

The American College of Sports Medicine (ACSM) has issued position statements on exercise and fluid replacement that are widely referenced in athletic training and sports medicine. Their guidance addresses both the risks of dehydration and — importantly, the risks of overdrinking.

The ACSM recommends that individuals consume adequate fluids during the 24-hour period before an event and drink about 500 ml (about 17 ounces) of fluid about 2 hours before exercise to promote adequate hydration and allow time for excretion of excess ingested water.

During exercise lasting less than one hour, the ACSM states that there is little evidence of physiological or physical performance differences between consuming a carbohydrate-electrolyte drink and plain water. For exercise lasting longer than one hour, additional considerations around carbohydrates and electrolytes apply — discussed below.

The ACSM's position on the risks of overdrinking is equally important and less frequently cited in popular coverage. Athletes need access to water to prevent hypohydration during physical activity but must be aware of the risks of overdrinking and hyponatremia. Hyponatremia, a potentially serious condition caused by low blood sodium levels — can result from consuming excessive quantities of fluid, particularly hypotonic solutions such as plain water, without adequate sodium intake.

Sports Drinks: What the AAP Actually Says

The role of sports drinks in youth athletics is a topic on which the AAP has published clear guidance. Their position is specific and worth understanding accurately.

For most activities, water is best for activities that last less than an hour. For exercise longer than an hour, water is a great choice but flavored sports beverages bring the added benefit of carbohydrates and electrolytes, which replace sugar and minerals lost through sweat.

The AAP Committee on Nutrition and the Council on Sports Medicine and Fitness has stated that for the average child engaged in regular physical activity, including many sports, utilizing sports drinks in lieu of water is generally unnecessary. Furthermore, frequent intake of the added sugar provided by sports drinks may adversely affect the appropriate balance of carbohydrate, fat, and protein intakes needed for optimal growth, development, body composition, and health.

However, the AAP does identify circumstances where electrolyte and carbohydrate supplementation via sports drinks may be appropriate for pediatric athletes. These include, as outlined by registered dietitian Kelly Jones MS, RD, CSSD: tournaments with prolonged exposure to unusually hot and humid environments, repetitive exercise or events with inadequate recovery time between practice or events, and prolonged vigorous activities lasting longer than 60 minutes.

On energy drinks specifically, the position is unequivocal: the American Academy of Pediatrics and World Health Organization have released strong statements against child consumption of energy drinks. Energy drinks are not appropriate for children or adolescents engaged in sports.

How to Monitor Hydration Status

Several practical methods for monitoring hydration status in youth athletes are described in the scientific literature. The most accessible are urine color observation and body weight change before and after exercise.

Urine color is widely used as a practical indicator. Research published in the European Journal of Clinical Nutrition and referenced by the Gatorade Sports Science Institute supports that first morning urine — through observing color — is a viable complementary method for generally confirming sufficient water consumption or revealing potential underhydration.

The CHOC (Children's Hospital of Orange County) pediatric sports medicine team describes the standard urine color targets: you'll know your child is hydrated enough if their urine is clear. If not, it will be the color of lemonade.

Body weight comparison before and after exercise is described by both the ACSM and the AAP as a reliable method for estimating fluid loss during a training session. The AAP notes that if an athlete weighs more after exercise than before, then the athlete is consuming too much fluid.

The ACSM recommends that the most effective way to ensure hydration is to utilize pre- and post-exercise weight measurements to determine and replace fluid loss. This method is used by athletic trainers and sports medicine professionals and can be adapted for use at home.

Recognizing Dehydration

The American Academy of Pediatrics Committee on Sports Medicine identifies the following signs of dehydration in young athletes. As documented by CHOC pediatric sports medicine, early warning signs include: decreased attention, complaints of stomachaches, and dropping to one knee.

Today's Dietitian, summarizing the sports medicine literature, lists a broader set of symptoms: noticeable thirst, irritability, fatigue, weakness, nausea, headache, muscle cramping, dizziness or lightheadedness, dark yellow urine or no desire to urinate, difficulty paying attention, and decreased performance.

An important note on thirst as an indicator: thirst is a sign that your athlete is already dehydrated. This is why pediatric sports medicine guidance consistently emphasizes drinking at regular intervals during training and competition rather than waiting for a gymnast to report feeling thirsty.

Post-Exercise Rehydration

Replacing fluid losses after exercise is as important as drinking during it. The ACSM's guidance, as summarized by the German Nutrition Society in their 2020 position paper on fluid replacement in sports, states that for rapid and complete rehydration, approximately 1.5 litres of fluid per kilogram of weight loss is recommended.

For most youth athletes at standard gymnastics practice or competition length, however, the same source notes that if body weight is reduced by less than 5% and there is no other physical activity within 24 hours, the consumption of normal meals and snacks combined with adequate amounts of water is sufficient to replenish fluid and electrolyte levels.

According to a CHOC pediatric sports medicine specialist, the first 30 minutes after exercise is key when it comes to rehydration and recovery.

Heat-Related Considerations for Gymnastics Facilities

Most gymnastics training takes place indoors, which reduces, but does not eliminate — heat-related hydration concerns. Gyms with poor ventilation, or in warm climates without air conditioning, can present elevated temperature and humidity conditions. The AAP Committee on Sports Medicine has established specific guidance for these scenarios.

The American Academy of Pediatrics Committee on Sports Medicine recommends that young athletes take 5- to 10-minute water breaks every 30 minutes whenever the heat index reaches 82 degrees or higher. During these breaks, athletes should rest in shaded or cooler areas and remove any heat-retaining equipment.

The AAP also places responsibility on meet organizers: youth sports governing bodies, tournament directors, and other event administrators should provide adequate rest and recovery periods of two or more hours between same-day contests in warm to hot weather to allow sufficient recovery and rehydration.

Individual Variability

It is important to note that fluid needs vary considerably between individuals. Research published in Nutrients (2024) found that sweat rate and electrolyte losses have a large inter-individual variability, and that a personalized approach is recommended. This means that published guidelines represent population-level averages and should serve as starting points rather than rigid targets.

Factors that influence individual fluid needs include body size, training intensity, ambient temperature and humidity, fitness level, and the duration of activity. The German Nutrition Society's position paper on fluid replacement states that fluid requirements in sports are based upon individual sweat rates, which can vary considerably both between and within individuals.

For gymnasts at the competitive level who train multiple hours per day across multiple days per week, consulting a registered sports dietitian for individualized fluid recommendations is advisable. Generic guidelines are a reasonable foundation; personalized assessment provides more accurate guidance.

Summary of Key Points

The following summarizes the evidence-based positions of recognized sports medicine and pediatric bodies on hydration for young athletes:

• A significant proportion of young athletes begin exercise already mildly dehydrated, based on multiple studies reviewed in a 2025 systematic review in Nutrients.
• The AAP recommends fluid intake at regular intervals during exercise, with specific volume targets by age and body weight.
• For exercise lasting under one hour, plain water is generally sufficient, per the ACSM. Sports drinks are not considered necessary for most short-duration youth sport activities, per the AAP.
• For exercise lasting longer than one hour, or in events with repeated bouts of activity and limited recovery time, electrolyte and carbohydrate supplementation may be appropriate, per the AAP.
• Energy drinks are not appropriate for children or adolescents, per the AAP and WHO.
• Both dehydration and overdrinking carry health risks. The ACSM advises against forcing fluid intake beyond thirst during normal exercise durations.
• Urine color and body weight change before and after exercise are practical monitoring tools supported by the scientific literature.
• Individual fluid needs vary. The guidelines above represent population-level recommendations, not individualized prescriptions.