Australian Cycling Forums - Bicycles Network Australia

‪I would appreciate people’s advice. ‬

‪The other night I sat on the bed and leaned forward to tie shoe laces. I got a loud sound in one ear and felt really dizzy. This probably lasted for about a minute. Raced to local ED who did bloods and diagnosed it as probably postural hypotension. I had had a dizzy spell the week before too just before going to sleep but nothing very serious. They were also concerned as my heart rate was 46. I am around 50 yo.‬

‪I have been dieting and cycling around 10 hrs, 2 x 3.5 hours sessions and a 2.5 hour session ,per week of very hilly courses. Lost around 8kg in 2 months. I don’t use any supplements and just drink water for cycling.‬

‪Went and saw my GP the next day and he said not to worry about it and see if it happens again.‬

‪I have two opinions from two doctors, should I get a third?‬

You most like have salt

You most like have salt low

Put one scoop (not the recommended 2 or 3) of Staminade in one bidon of water on your rides. Just top it up with water as you go. That’s enough for most rides of 2-3 hours.

If you’ve lost 8 kgs you have less on-board reserves, and are probably riding better (read harder) than before as well. You need to keep your energy and fluid levels up though.

**This is just my experience under similar scenario.

uad782 wrote:‪
‪I have been dieting and cycling around 10 hrs, 2 x 3.5 hours sessions and a 2.5 hour session ,per week of very hilly courses. Lost around 8kg in 2 months. I don’t use any supplements and just drink water for cycling.‬
‬

Symptoms:

Hypotension or orthostatic hypotension.
Bradycardia or tachycardia.

... taken from...

Wikpedia - anorexia nervosa

Not saying you have anorexia. But you might want to eat more given your body is (to a degree) shutting down. Been there, done that...

Because you only are drinking water, you are flushing out electrolytes. ie potassium, magnesium and sodium.

Next time you see you doc, ask them to check your blood electrolytes.

Baalzamon wrote:Because you only are drinking water, you are flushing out electrolytes. ie potassium, magnesium and sodium.

Next time you see you doc, ask them to check your blood electrolytes.

Except, as per first post, they did that at ED - they would have picked up any gross electrolyte issues. Not saying that some salts in the drinks isn't a bad idea, depending on input/output... but it's fairly hard to cause issues *unless* you are drinking stupid amounts of fluid - and that would have shown up in the blood tests (I hope!).

At a rough guess... to lose 8Kg in two months means a calorie deficit of around 900kCal a day. Of course, a stack of that could be glycogen & associated water, heck I've had at least two periods where I've dropped 6 - 8Kg in a month! But given the OP is doing 3.5h rides on hilly terrain... sounds "trained", and probably just losing weight too quickly and the body is retaliating.

Thanks everyone. I will let you know the results

uad782 wrote:Thanks everyone. I will let you know the results

BTW - over the years, I've had EXACTLY the same symptoms (tinnitus, postural), usually when losing weight and it goes away when I'm putting weight back on (damn it!). Discussed with doctors... no real outcomes.

You know you are over-doing it (calorie deficit) when you start nodding off when sitting down because the HR drops off. I have a sit-stand desk at work - hard to fall asleep standing, and the standing brings the HR up by around 10 BPM. But meetings are a real struggle.

The first time is scary, got out of bed, stood up and hit the floor.

That was over 30 years ago, naturally low blood pressure and being sick at the time.

Since then, learnt the signs and move more slowly when I am sick or the body is recovering (from sickness or riding).

Never had the ear thing.

ps I am almost 60, my resting HR is a little higher than yours, but well under 60. Recently, similar hours, no hills instead intervals, my diet is less structured than yours, now riding with just water, increase intensity and moderate increase in volume, dropped 7kg in 5 months and yes my orthostatic hypotension is playing up more than usual (ie getting dizzy)

Do you get night cramps?

Ivanerrol wrote:Do you get night cramps?

Yes. Plus dizzy sometimes when crouched down with my neck forward like when looking at something on a bottom shelf and then standing up.
But i have moderate high blood pressure.

The third doctor called it Vasovagal syncope. Thanks for everyone's replies.

uad782 wrote:The third doctor called it Vasovagal syncope. Thanks for everyone's replies.

Vaso-> relates to veins
Vagal-> system of nerves that regulate breathing, heart rate etc
syncope-> fainting

Ie it describes your symptoms rather than necessarily identifying an underlying cause

find_bruce wrote:

uad782 wrote:The third doctor called it Vasovagal syncope. Thanks for everyone's replies.

Vaso-> relates to veins
Vagal-> system of nerves that regulate breathing, heart rate etc
syncope-> fainting

Ie it describes your symptoms rather than necessarily identifying an underlying cause

Not quite. It refers to an episode where enhanced vagal effects on the heart (negative chronotropic - slowing) causes a transient drop in cardiac output and thus a drop in blood pressure. The classic situations are soldiers on parade, standing up suddenly and also as a result of some drugs/medications.

I'm a doctor and a 250km a week cyclist.

Offhand I'd agree with your GP in that you likely have nothing to worry about, provided you're not on any medication that will lower your blood pressure.

The most likely cause is a combination of things - increased vagal tone (hence the low HR), decreased peripheral resistance (more arteries and veins optimised for the cycling) and potentially a little bit of dehydration on that day. The more serious would include an underlying heart rhythm issue (I'm pretty sure an ECG would have been done in ED, though they only catch it if it's happening) or the rarer endocrine causes. So vasovagal syncope is a reasonable explanation

Personally I went through a stage where I experienced mild presyncopal symptoms quite regularly. I'm 41 and 61kg with a BMI of 21 and resting heart rate somewhere around 40 so I figured it was the case as above. I just thought my system was best optimised to hammering up a hill at 200bpm and couldn't cope with a little bit of dehydration and wandering around the house at 40bpm.

This is just general advice, I don't know anything about your medical history or actual weight, but it does sound like you've consulted the appropriate people who have done appropriate things. I say these things in my experience as a 250km a week cyclist rather than anything related to my qualifications.