While it is not uncommon to feel faint, nauseous or dizzy while exercising, there are several things you can do to prevent it.
1. Stay hydrated
Drink lots of water in the lead-up to your workout. Sip water regularly while exercising but avoid taking big gulps as it can lead to vomiting.
2. Do not eat straight before a workout
Ideally, you should eat a meal containing carbohydrates ninety minutes before your workout for energy. If you must eat right before a workout, have something small and easily digestible.
3. Sugary or energy drinks
If you do start to feel nauseous, a sugary drink can help raise your blood sugar and ease the faintness.
4. Start slow
If it is your first time exercising after a long time, start slow, make sure to get plenty of rest and focus on proper breathing.