Normally, I'm not really concerned about it (unless it gets too bad) but when my wife identified that it often limits her before her physical abilities do, that made me stop and think. I have to admit that it's the same thing for me - it's not my legs or arms or whatever that's fading out, it's the dizziness that stops the workout.
I decided to look around a bit to see what some of the more common causes are of this (I was initially only aware of a few of them). Here's what I found - hopefully others out there can benefit from this too. I think #6 and #7 were our culprits last night.
- Too much too soon. If you're new to exercise, or new to a particular type of exercise, you need to allow some time for the body to adapt to the new stresses. In general, this is just like the approach to other forms of training - start slow, and incrementally increase the intensity to allow the adaption to occur.
- High/low blood pressure, cardiac issues and anemia. Go see a doctor if you have these concerns (and stop listening to me!).
- Improper hydration. I've only recently discovered how poor hydration on a long effort affects me. Normally, this shouldn't affect you unless you're in a hot environment or a long-duration activity...or you drank only coffee all day before working out.
- Too much caffiene. Loads of caffiene can spike your heart rate higher than normal and just plain make you dizzy without even exercizing.
- Poor fuelling. Not having sufficient calories stored up, or not replenishing them during longer/harder sets will affect you just like poor hydration will.
- Blood pooling. I get this all the time. When you work large muscle groups, the body tries to put more blood at those muscles to help them work hard. The affect is that there's a lower concentration of blood in other areas. If you've done squats and then stood up too fast, you know what this is like. You'll also feel this in wobbly legs after a long, hard swim.
- Improper breathing. Our cardio KB instructor identified this one to us. Here's a direct quote that I found online: "starving your body of oxygen by shallow breathing or holding your breath during exercise is a definate no no. Concentrate on your breathing and this will not only get you through your exercise session but can improve your lung capacity and control your heart rate too."