I am 54 yrs. old and have been lifting weights for about a year. The past several days I have experienced light-headedness after straining on the weights...particularly the bench press. Yet nothing else much has changed, including the amount of weight lifted. Is this light-headnedness a common problem in weight lifting, or likely a symptom of something else?
A woman I used to train used to get light-headed when exercising and usually had to stop. My initial thought was because we were doing exercises that had her in a horizontal position (bench, mountain climbers, planks...) and therefore may induce a lower blood pressure to the head and when she stood up, the immediate introduction of gravity drained the blood from the head. This may have caused ischemia or decreased blood flow to her head and caused light-headedness.
It turned out that she was anemic or iron-deficient. This got me thinking of different causes of exercise induced dizziness. From what I know it can be from lack of blood to an area as a result of: standing up too soon from a horizontal position, not hydrated enough causing low blood volume/low blood pressure, not recieving enough iron or other vital nutrients to produce and carry out the functions of red blood cells, or possibly a poor diet in the long term.
This may also be a result from doing too much weight. Going to fatigue as opposed to failure in weight lifting still induces a strength gain and healthy response. You may not be able to maintain the cardiac output demanded for these certain lifts like you used to when you were younger (no offense, honestly).
I've also heard of blood pooling be a culprit. When blood pools it usually pools where nutrient rich blood needs to pass through to provide additional resources for your exercising muscles. When this cannot happen in places like your head, you may get a headache or become dizzy. I would have no idea why you have blood pool during exercise, maybe a poor diet restricts the blood demand while exercising (although if you're 50+ and you have the initiative to continue exercising, you probably have the initiative to eat fairly well.)
The brain uses primarily sugar for energy. It's possible you have to eat or continue to eat a little something to prevent feeling dizzy.
I work very closely with hospitals, gyms, emergency services and my own clients who range in diseases and conditions but I, like everyone, sometimes are wrong about things and don't know what I'm talking about. I am not a doctor so if this problem continues you should probably consult a physician. The culprit could be one, multiple, or something other than what I've listed here. Try to maybe eat something during exercise, stay hydrated, be careful sitting up too fast, watch what you eat and monitior yourself and hopefully this problem will resolve itself. If not, head to your MD.
Sorry this is so long but I hope this has been helpful.