It's normal to incur a bout of dizziness now and again when you exercise. However, regularly feeling lightheaded or dizzy during or after a good workout is a cause for concern and could be an indicator of a serious problem. Figuring out the cause is key to getting the treatment you need and modifying your workouts to compensate and to prevent these symptoms from returning.
Causes
The causes of dizziness and lightheadedness when exercising are varied. For some, it's as simple as being dehydrated. Dehydration can certainly make you feel exhausted and woozy. Heat exhaustion is another possible cause. However, heat exhaustion could lead to heat stroke, which is very serious. Failing to eat enough calories could also leave you feeling dizzy and ill prepared for working out.
Prevent Dehydration
Failing to drink enough water zaps your body of energy and leaves you feeling woozy on exertion. According to the American Academy of Family Physicians, you need up to 20 oz. of water a few hours prior to exercise plus 8 oz. for every 20 minutes of activity. Staying hydrated keeps your body functioning as it should and staves off that uncomfortable feeling as though you're going to pass out.
Eat Enough Calories
Failing to eat enough could also leave you feeling fatigued and ready to pass out. In fact, you need at the very least 1,200 calories if you're a woman and 1,500 calories if you're a man a day to stay at your current weight. Use a metabolic rate calculator to determine how many calories you need to consume each day to stay at your current weight and to stay nourished.
Lack of Rest and Recovery
In some cases, failing to give your body enough time to rest between workout sessions could be the cause of your dizziness and lightheadedness. Moderate aerobic activity is fine for everyday performance, but vigorous workouts should be performed at least a day between exercise sessions. The same goes for strength training. If you lift weights that are the absolute heaviest you can lift without breaking form you must rest at least 48 hours before exercising the same muscle group again to avoid muscle fatigue and the dizziness that can accompany it.
