I've heard different things on this. What is the truth?
I've heard different things on this. What is the truth?
Your blood volume is reduced, therefore your ability to transport O2 to your muscles is lessened. You can still run, of course, but at a slightly reduced efficacy until your normal blood volume and red cell count are restored.
Could giving blood hurt your season? It seems like it would.
mr bat wrote:
I've heard different things on this. What is the truth?
Don't know the answer, but here's a kinda funny story related to it..
When i was in high school, our 4X4 lead leg who consistanly ran 49s got blood drawn the day before our regional meet. When we saw the band aid on his arm we all got pissed and flipped out! He said that he'd be fine for the race because (reached into the pocket of his sweats) he's "eating tons of skittles to get his blood sugar back up"!
He ran a 53 if I'm not mistaken. Dunno if it was the blood or skittles.
What Active People Need to Know
Competitive athletes and those who work out often wonder if donating a pint of blood will impair their athletic performance or fitness goals. They have good reason to wonder. After all, blood donation can influence hydration status and the oxygen-carrying ability of red blood cells.
In some situations, athletic pursuits and the public's need for blood are cast as competing interests—for example, when coaches advise student-athletes to decline donation requests...
...Active people and athletic administrators often turn to physicians for advice; however, few studies on blood donation and exercise have been published. More often, recommendations are based on what physicians know about basic hematology and exercise physiology. After donating 450 mL (1 U) of whole blood, plasma volume falls 7% to 13%, then recovers within 24 to 48 hours. The hemoglobin level decreases by 10 to 20 g/L. With an adequate iron supply, hemoglobin returns to baseline after 3 to 4 weeks.
Exercisers and Recreational Athletes
Marvin Adner, MD, a hematologist and internist in Framingham, Massachusetts, and medical director of the Boston Marathon, says that blood donation should not be a concern for active people who are not world-class athletes—as long as they are not iron deficient. He notes that though hemoglobin values will be lower than normal a few weeks after donation, blood donation does not erode fitness effects.
Adner cautions active people who donate blood to avoid taking regular iron supplements unless they are iron deficient from giving blood. Iron intake can cause symptoms in patients who have hereditary hemochromatosis. Iron supplements can also mask the anemia of colon cancer and damage the heart. "Unfortunately, many athletes—especially those who don't eat red meat—have borderline iron deficiency," he says.
Donald M. Christie, Jr, MD, an internist and sports physician in Lewiston, Maine, says hydration is the best recovery strategy. Donors need to drink not only what is offered afterward at the blood donation center, they need to aggressively hydrate over the remainder of the day, says Christie, who is an editorial board member of The Physician and Sportsmedicine. "Noting the color of the urine is a good way to gauge hydration status," he says.
He advises endurance athletes to think of the blood donation day as a rest day, and to tread cautiously the next day because hydration stores may not be replenished and delayed vasovagal effects may occur. Christie says though the performance decrement would be slight in an endurance athlete, blood donation should have virtually no effect on strength or short-burst activities.
In a study that sought to determine the effects of blood donation on older exercisers, researchers measured submaximal and maximal working capacity and blood viscosity in younger donors, older donors, and older controls the day before and after blood donation. They found that mean submaximal and maximal values increased the day after donation in all groups, but that increases were only significant in the younger donors. Plasma viscosity decreased significantly in both donor groups. The authors concluded that a single blood donation did not alter the physical fitness of otherwise healthy people.
Extracted from The Physician and Sportsmedicine
"The hemoglobin level decreases by 10 to 20 g/L. With an adequate iron supply, hemoglobin returns to baseline after 3 to 4 weeks."
In other words: yes, it can ruin a whole season, and has done so for cross-country runners in real-life situations. This happened in my personal coaching experience.
The 3-4 weeks with lowered hemoglobin do not occur in a vacuum; they represent a period when you are unable to gain greater conditioning (while your competition moves forward), and are (somewhat) more susceptible to illness and/or injury while you attempt to continue training/racing.
An endurance runner should never donate blood during the competitive season or in the last several weeks of preseason training. If you really feel compelled to donate, do so sometime between the end of xc season and the beginning of December, or during the couple of weeks following the end of outdoor track.
I was officiating (high jump) at a qualifying meet for the conference championships and was surprised when one of the favorites couldn't clear the opening height. She was closer to going under the bar than over it. I asked her what was wrong. She told me she had donated blood that day. She also asked me not to mention it to anyone.