The American Red Cross recommends that blood donors do not perform any exercise or heavy lifting for at least five hours after donating blood. Donors sometimes feel dizzy or weak after giving blood, so it is important to exercise caution when being physically active after donation.
For student athletes, the American Red Cross recommends waiting at least 12 hours after blood donation before resuming any strenuous exercise. It is best to schedule a blood donation in between game or practice days or on days that an individual does not plan to participate in physically demanding activities.
It is also a best practice to drink extra fluids, about four glasses, to replace the lost fluids after donation. It is also recommended to eat healthy, iron-rich foods to replace the iron lost during blood donation.