When you donate blood, you could be saving a life. The blood-donation process takes five to 10 minutes, but it could make a big impact for someone whose life depends on that blood. After you've donated blood, you might be anxious to return to your normal activities, but it is prudent to give yourself time to rest. The donation center will likely offer cookies and juice to help relieve a dizzy or faint sensation after donating, but weakness may linger when you attempt to exercise later in the day.
Side Effects
While the side effects from donating blood are generally mild, they may be enough to interrupt your regular workout schedule. You may feel dizzy or weak directly after the procedure. Donation centers offer snacks to help stabilize your blood sugar levels and replenish fluids after donating. Most people are ready to leave the donation center after 10 or 15 minutes, but if you feel dizzy or faint, stay in the rest area until the feeling passes, particularly if you've driven to the donation center on your own. Even when you leave, you may have lightheadedness throughout the day, the American Red Cross cautions on its website.
Performance
Donating blood usually has little lasting effect on the average person. After the initial 10 minutes, most donors can resume regular activities. Still, if you're an avid athlete, you may notice a dip in your performance after donating blood. De Anza College faculty member Mary Donahue cites a study that found cyclists' performances to be diminished up to a week of donating blood. While going to the gym in the days after your blood donation is not strictly prohibited, it may affect your athletic performance and results.
Wait Time
You should avoid strenuous activities such as lifting weights and performing endurance cardiovascular exercise for at least four to five hours after your blood donation. Give your body time to recover from the donation --- otherwise you could find yourself feeling dizzy and lightheaded, a dangerous combination when lifting weights. In general, it's best to listen to your body; some people may react more strongly to a blood donation than others. Wait the recommended five hours before heading to the gym, and stick to lighter weights and lower-impact workouts for the day.
After Care
Donating blood is a routine procedure and is generally very safe. Still, you could have a reaction that requires special care and rest. If you feel dizzy or lightheaded during the day, lie down and elevate your feet until the feeling passes, the Red Cross recommends. If you notice any bleeding around the injection site, apply pressure until the bleeding stops. If bruising is a problem, an ice pack can relieve swelling and reduce pain. Within 24 hours, you should be back to normal, even if your performances is slightly altered.
