I thought I'd write and share about my recent experience, partly as a warning to others and partly to see if others have had or heard of similar experiences.
On Sunday morning during navy reserves, our blood bank came to take blood donations. I always mean to give often, but I actually hadn't for about seven years. So anyway, I certainly thought I should, and I did. After the donation, I felt great. I had expected to feel a little tired and sluggish, but I pretty much felt the same. My arm didn't feel too sore either. I had a beef brisket sandwich and baked beans for lunch and some flatbread and salad for dinner. The next day, I had a mix of non-fat yogurt, raspberries, oats, and almonds for breakfast and a spinach, mixed greens, and hummus sald for lunch. I didn't exercise at all on Sunday.
Last night (Monday), however, I decided to do my workout on my rower. I felt great as I was about to begin, but after I started, I realized it was tougher than normal. I try to maintain 800 Cal/hr as my pace and go until I reach 400 Cal. I decided I would just try to go for 300 Cal. Anyway, near the end (at about 250 Cal), I decided to try to finish strong and finish a minute early (21:30 rather than 22:30), during which time I was generally over 1000 Cal/hr. I accomplished that feat, but after I got off and stood up to stretch, everything got blurry and dark and I felt really dizzy and uncoordinated. (I've never been truly drunk, but it was easily worse than the effects of three alcoholic drinks.) At first I thought it was no big deal and would only last a few seconds, but the situation wasn't improving. In fact, it seemed to be getting worse. I walked upstairs to the family room and sat down on the couch for a couple minutes, and then I walked to the kitchen and, feeling like I was about to pass out, I laid myself down on the floor. Lying on my back certainly made things better. After a few minutes, I thought I was fine, and decided to slowly stand up. Then, it got bad again, and I again felt like I was going to pass out. I went back to the floor and stayed there for probably about ten minutes. After that, I made my way to a chair, and after a few minutes there, I got back on my feet and felt fine.
This experience was really scary and like nothing I've ever experienced before. In the past, my body always seemed to limit how much it would give me. Rather than exert itself to the point of passing out or anything like that, my body would just start limiting my output (e.g., keeping me from sprinting at the end of the race). So, I always felt I could press myself however hard I wanted, knowing that my body would keep me from overdoing it. In this case, however, it seems my body didn't hold me back. Plus, given my lack of experience with giving blood, I really had no way of knowing how it would affect me about 1-1/2 days later. Apparently, I still wasn't quite back to normal, even if I had to start exercising a little to discover that. I do think it was good to exercise last night, but obviously I should have taken it easy as well as had more of a cooldown following the most strenuous part of the exercise.
For what it's worth, although I can by no means consider my level of fitness to be "athletic", I have no health problems. My blood numbers are always within the desirable range, including blood pressure, resting pulse rate, cholesterol, triglycerides, and hemoglobin numbers. I'm pretty sure my problems last night were due almost entirely to a lack of oxygen to the brain resulting from a lower level of hemoglobin in the blood.
Anyone ever had anything similar happen to yourselves or someone you knew? Any additional thoughts?
On Sunday morning during navy reserves, our blood bank came to take blood donations. I always mean to give often, but I actually hadn't for about seven years. So anyway, I certainly thought I should, and I did. After the donation, I felt great. I had expected to feel a little tired and sluggish, but I pretty much felt the same. My arm didn't feel too sore either. I had a beef brisket sandwich and baked beans for lunch and some flatbread and salad for dinner. The next day, I had a mix of non-fat yogurt, raspberries, oats, and almonds for breakfast and a spinach, mixed greens, and hummus sald for lunch. I didn't exercise at all on Sunday.
Last night (Monday), however, I decided to do my workout on my rower. I felt great as I was about to begin, but after I started, I realized it was tougher than normal. I try to maintain 800 Cal/hr as my pace and go until I reach 400 Cal. I decided I would just try to go for 300 Cal. Anyway, near the end (at about 250 Cal), I decided to try to finish strong and finish a minute early (21:30 rather than 22:30), during which time I was generally over 1000 Cal/hr. I accomplished that feat, but after I got off and stood up to stretch, everything got blurry and dark and I felt really dizzy and uncoordinated. (I've never been truly drunk, but it was easily worse than the effects of three alcoholic drinks.) At first I thought it was no big deal and would only last a few seconds, but the situation wasn't improving. In fact, it seemed to be getting worse. I walked upstairs to the family room and sat down on the couch for a couple minutes, and then I walked to the kitchen and, feeling like I was about to pass out, I laid myself down on the floor. Lying on my back certainly made things better. After a few minutes, I thought I was fine, and decided to slowly stand up. Then, it got bad again, and I again felt like I was going to pass out. I went back to the floor and stayed there for probably about ten minutes. After that, I made my way to a chair, and after a few minutes there, I got back on my feet and felt fine.
This experience was really scary and like nothing I've ever experienced before. In the past, my body always seemed to limit how much it would give me. Rather than exert itself to the point of passing out or anything like that, my body would just start limiting my output (e.g., keeping me from sprinting at the end of the race). So, I always felt I could press myself however hard I wanted, knowing that my body would keep me from overdoing it. In this case, however, it seems my body didn't hold me back. Plus, given my lack of experience with giving blood, I really had no way of knowing how it would affect me about 1-1/2 days later. Apparently, I still wasn't quite back to normal, even if I had to start exercising a little to discover that. I do think it was good to exercise last night, but obviously I should have taken it easy as well as had more of a cooldown following the most strenuous part of the exercise.
For what it's worth, although I can by no means consider my level of fitness to be "athletic", I have no health problems. My blood numbers are always within the desirable range, including blood pressure, resting pulse rate, cholesterol, triglycerides, and hemoglobin numbers. I'm pretty sure my problems last night were due almost entirely to a lack of oxygen to the brain resulting from a lower level of hemoglobin in the blood.
Anyone ever had anything similar happen to yourselves or someone you knew? Any additional thoughts?
