b_t

Before I invest in a trip to a sports doctor or medical analysis, I wanted to solicit some opinions.

I'm nearly 50. I had never been particularly athletic or active but started light weight lifting 3 years ago and cycling last year. My toughest ride last year was a 70 mile +5600 ft recreational event.

I did spinning and cross-training over the winter. Now that spring is here, I'm riding 4 days/week, something like 20/20/40/70 for mileage. Most of my riding is on flat/rolling hills, 70-75% of MHR, occasionally higher on a longer hill. Avg speed varies from 16-18mph, so nothing too strenuous.

I'm now starting to feel lightheaded the day after, but not during rides, sometimes even the 20 milers. I talked to my physician last month at my annual exam, but didn't get too much useful in terms of feedback other than that maybe I'm going to hard. I don't think I am. I can talk comfortably while riding and don't have much soreness the next day.

I had all the usual lab work. Cholesterol, blood count, and everything else was extremely healthy. My BP and resting heart rate have been trending down over the last few years as one would expect. Resting heart rate was 70 and this year is consistently 45-50. BP started at 130/70 and is now 95/49.

My regular diet is solid. I'm drinking 16-20 oz per hour (50/50 gatorade/water), and consuming 500 calories per hour (energy bars/bananas) while riding. Avg temperature is 50-60, so I don't think hydration is the issue, and I've cut out my caffeine. Weight is withiin a pound or two before and after rides (I'm 6'1", 183lbs).

I'm starting to think this could be low blood pressure related. Does anyone here have any experience with this, or is 95/49 within normal range for endurance cyclists?

rpenmanparker 

Yes, it is a specific, transient form of low blood pressure caused by sudden standing up. Most commonly it is what is called "postural hypotension" or "orthostatic hypotension". When you feel lightheaded, just bend over to get more blood to your head until it passes. Not a problem in most cases. Make sure you replenish glycogen, electrolytes and fluids. That will help to prevent the occurrence.

datlas 

Have a salty snack and some extra fluids.

Do it now and thank me later.

hamster

I just measured my blood pressure and got 105/63 @ 51..55 bpm (sitting in a chair in front of the computer). 95/49 sounds like it may be a bit extreme (and 49 puts you within the clinical definition of hypotension), but it's not uncommon for endurance athletes to have low BP.

JimF22003

I've done hundreds of century rides. After particularly hard ones, I get this the next day still. It passes. Wouldn't hurt to see a doctor though.

FLvector

Does this dizziness occur while sitting and walking around, or only when standing up from a sitting or reclined position? If it occurs when suddenly standing it is fairly common and there's ways to avoid the dizziness. If occurring while sitting or continues while standing for longer length of time I'd discuss this further with your doctor.