Regardless of the type of physical activity, you should always stay hydrated, as dehydration can be a cause of fatigue, dizziness, diarrhea or heatstroke.

How much water you need depends on your weight, sweat rate, and exertion. Among symptoms of dehydration are headaches, dry mouth, and dark urine or inability to urinate at all.

Here's a guideline on how you can define your hydration needs:

• Measure your weight before walking
• Drink as much water as you need during the walk
• Upon getting home weigh yourself without clothes and before using the toilet
• The difference in weight is a result of the hydration level decrease (let's be fair, it can't be caused by fat blast as it is not possible to lose 2 pounds from a 60-minute walk)
• Do that each time you work out, and increase the amount of water until you see no difference in your weight before and after your training.

Follow these steps to determine how much water you need to drink during your walk.