For one who works out regularly, it is ever more pertinent to drink up – be it water or sports drinks – to avoid dehydration, replace the fluids lost through perspiration and boost exercise performance. However, often during workouts, excessive water or sports drink intake can occur mainly due to unawareness of overhydration and its consequence.

Overhydration is when one drinks more water than their body needs, leading to water intoxification or low levels of sodium in their blood. Sodium, potassium and calcium are three of the main electrolytes your body relies on in order to ensure your body has enough water, maintain blood acidity – or pH – and ensure proper muscle action. It is important to maintain the balance of these three electrolytes in your body.

Fluid needs vary widely among individuals so do check your hydration status before exercise. But don't depend on your thirst mechanism to tell you when and how much to drink. Thirst is a poor indicator of hydration status, as an athlete can lose over 1.5 L of body water before becoming thirsty.

A rule of thumb to ensure hydration and not overhydration is: aim to replenish 80% of the fluid lost.

Here’s how you can ensure you are hydrated during a workout:

• Drink about 500ml of water 2 to 3 hours before your workout
• Drink about 200ml of water 20 to 30 minutes before you start or during warm-up. You can also slip in half a banana to give your body the potassium it needs
• Drink small amounts of water or other fluids (about 200ml) at regular intervals (every 10 to 20 minutes) during your workout.
• Ensure to never feel ‘full’ of water
• Take in about 200ml of water no more than 30 minutes after the workout
• Snack up after long, hot workouts – preferably food with salts

Some signs of overhydration to look out for: nausea, vomiting, headache and change in mental status such as confusion and disorientation. As this can often be mistaken for dehydration, do monitor your daily water intake carefully to maintain safe hydration levels. Make sure to meet and not exceed your hydration needs.

References: livestrong.com, peakperformance.ca