Strength training and bodybuilding place a lot of stress on your body. Heavy weights that cause you to strain more than normal can affect your blood pressure and heart rate. Try to limit the number of sets and repetitions during heavy weight-load workouts, and focus on proper breathing to reduce the amount of stress on your body. Speak with your doctor if you consistently feel lightheaded after bodybuilding workouts.
Feeling lightheaded or dizzy during or after an intense strength training workout is not uncommon. The sensation comes from the increased strain placed on your heart when lifting heavy weights, which impacts your blood pressure. Many lifters hold their breath as they push or pull a heavy weight at the beginning of an exercise. The lack of oxygen intake while performing a strenuous action almost instantaneously causes the heart to beat faster, causing higher blood pressure. The heart does this to deliver the oxygen the body needs to complete the action. Dehydration can also contribute to lightheadedness. Drink plenty of water before, during and after a workout to keep yourself hydrated.
The lightheaded feeling during a workout typically passes after a few seconds. Once heart recovers, it can effectively pump blood and oxygen throughout your body again. If, however, you consistently experience dizziness and feel lightheaded for more than several seconds after an exercise, speak with your doctor. This could be a sign of a more serious underlying condition that is exasperated by straining when lifting weights. Conditions such as arrhythmia and cardiomyopathy can cause the heart to pump inadequate amounts of blood through your body. If you suffer from either condition, speak with your doctor before beginning a strength training regimen.
Presyncope and Orthostatic Hypotension
The medical term for feeling lightheaded and faint while remaining conscious is presyncope. Besides lightheadedness, symptoms of presyncope include pale skin, nausea and clamminess. Presyncope can result from many strength training exercises that involve lying on a bench or mat while lifting heavy weights. If you sit or stand up too quickly afterward, you may experience orthostatic hypotension -- a dramatic drop in your systolic blood pressure -- which results in lightheadedness.
Don't Hold Your Breath
Good breathing technique can help you control feelings of lightheadedness. If you lift heavy weights that cause you to strain, force yourself to breathe uninterruptedly throughout the movement. Exhale through to the top of the movement, then inhale as you return to the starting position. Holding your breath while lifting weights is not recommended, due to the strain it places on the heart and the spike it causes in blood pressure. These symptoms are especially important to consider if you are a person who has high blood pressure when not exercising.