Hydration advice fails when it becomes a fixed number for everyone. Sweat rate varies widely between individuals and between sessions, so the useful approach is to start training reasonably hydrated, drink according to thirst and sweat loss during the session, and replace fluid and sodium afterwards in proportion to what you lost. In Dubai, heat and humidity raise the stakes, especially for outdoor training and long sessions.
Electrolytes are not mandatory for every workout. They matter most when sweat losses are high, sessions are long, the environment is hot, or you are a heavy or salty sweater.
Why hydration affects performance
Fluid loss through sweat helps regulate body temperature during exercise. When losses become significant relative to body weight, performance, perceived effort, thermoregulation and cardiovascular strain can be affected, especially in hot conditions.
The practical training consequences are familiar: sessions feel harder, heart rate is higher at the same workload, concentration falls and endurance work becomes noticeably more difficult. Strength training in a hot environment can feel disproportionately fatiguing too.
ACSM guidance emphasises starting exercise well hydrated, limiting excessive fluid losses during exercise, and replacing fluid and electrolytes afterwards [1].
Why Dubai changes the calculation
Sweat rate is influenced by exercise intensity, duration, clothing, fitness, acclimatisation and the environment. Heat and humidity can increase sweat losses substantially, and humidity also reduces evaporative cooling efficiency.
That is relevant for outdoor sessions, beach training, padel and running during warmer months. It is also relevant for people who commute through the heat before training, who may already be behind on fluid before the warm up starts.
Air conditioned gyms reduce the problem, but they do not eliminate it. A hard conditioning session indoors can still create meaningful sweat loss.
How to estimate your own sweat rate
You do not need laboratory testing. A simple field method is to weigh yourself before and after a training session in similar conditions, with minimal clothing and after towelling dry, and account for any fluid consumed during the session.
The approximate change in body mass reflects fluid lost. Repeat it across a few different session types, for example an indoor strength session, an indoor conditioning session and an outdoor session, and you will quickly see how different your own sweat losses are.
This is far more useful than a universal rule. Two people in the same class can have very different needs.
When electrolytes actually help
Sodium is the electrolyte lost in the greatest amount in sweat. National Athletic Trainers Association guidance highlights sodium replacement during prolonged exercise, heavy sweating and hot conditions, particularly for people with high sweat sodium losses [2].
Most people eating regular meals in a normal week obtain plenty of sodium from food. That is why electrolytes are often unnecessary for a 45 to 60 minute indoor gym session. They become more relevant for endurance work, long outdoor sessions, back to back training, repeated sessions in heat, or individuals who finish sessions with visible salt on skin and clothing.
Potassium, magnesium and other electrolytes are also lost in sweat, but usually in smaller amounts relative to dietary intake. Marketing often exaggerates their acute importance.
A practical before, during and after framework
- Before: aim to arrive hydrated rather than trying to fix everything in the 10 minutes before the session. Include fluid with meals and consider a moderate drink in the hours beforehand.
- During: drink to thirst for typical gym sessions. For hot, long or heavy sweat sessions, drink more deliberately and consider adding sodium.
- After: replace fluid gradually alongside a meal or snack containing sodium. Large volumes of plain water at once are not the most efficient strategy after heavy sweat loss.
- Individualise: use your own sweat rate estimate rather than a fixed litre target copied from a fitness influencer.
Over hydration is also a risk
Exercise associated hyponatraemia can occur when excessive fluid intake dilutes blood sodium, typically during prolonged exercise. Symptoms may include headache, nausea, confusion, swelling and in severe cases far more serious outcomes.
A 2024 review reported a pooled prevalence of around 5% in endurance athletes, with most cases asymptomatic, and emphasised sensible fluid strategies rather than maximal drinking [3].
The practical message is balance. Do not chase dehydration, and do not force very large fluid volumes on the assumption that more is always safer. Anyone experiencing concerning symptoms during or after prolonged exercise should seek medical help.
Simple daily habits that prevent most problems
Keep a water bottle accessible during the working day rather than relying on a large catch up volume in the evening. Include fluid with meals. Watch for the pattern of high caffeine intake, long commutes and air conditioning producing an unnoticed shortfall.
Use practical indicators together: thirst, urine colour as a rough guide, body weight stability, and how you feel during training. No single indicator is perfect. What we eat also contributes fluid, so hydration is not only what you drink. Our pre and post workout nutrition guide pairs well with this.
What we do with clients at Project Reshape
We treat hydration as part of the training plan, particularly for clients who train outdoors, travel frequently or perform demanding conditioning work in hot months. Rather than assigning a universal water target, we look at session type, environment, sweat loss patterns, nutrition and symptoms, then adjust. It is part of the broader recovery approach in our executive wellness programme.
Frequently asked questions
How much water should I drink before a workout?
A practical approach is to drink moderately in the hours before training so you are not starting dehydrated, rather than drinking a large volume immediately beforehand.
Do I need electrolytes for a one hour gym session?
Often not, if you eat normal meals containing sodium and the session is indoors and moderately intense. Electrolytes become more relevant with heavy sweating, heat exposure and longer sessions.
Is urine colour a reliable hydration check?
It is a rough practical indicator, not a precise measurement. Supplements, some foods and medications can change colour independently of hydration.
Can you drink too much water?
Yes. Drinking excessive fluid, particularly without sodium during prolonged exercise, can cause exercise associated hyponatraemia, which is a medical emergency.
Are sports drinks necessary?
For most gym sessions, no. They become more useful in longer or hotter sessions where fluid, sodium and carbohydrate replacement matter.
Conclusion
Good hydration is not complicated, but it is individual. Start sessions reasonably hydrated, adjust intake to real sweat losses, add sodium when conditions justify it, and avoid extremes in either direction. In a hot climate, that simple framework protects performance and safety far better than a fixed daily number.
Next step
- Book your free assessment: request a consultation and we will match training, nutrition and hydration to how you actually train in Dubai.
- Related reading: what to eat before and after training, training and nutrition together, executive wellness.
Sources
- [1] American College of Sports Medicine. Exercise and Fluid Replacement position stand.
- [2] McDermott BP, et al. NATA Position Statement: Fluid Replacement for the Physically Active. J Athl Train. 2017;52(9):877-895.
- [3] Li H, et al. Prevalence of exercise associated hyponatraemia in endurance athletes: systematic review and meta-analysis. 2024.
