Australian Cycling Forums - Bicycles Network Australia

Had a couple of weeks in Fiji and picked up a nasty dose of food poisoning that made me quite ill for a good two weeks + I wont go into details but I lost a lot of fluids in that time...

So it was three weeks off the bike but now my heart rate is really high compared to before the illness. My average for an effort 35k commute was near 150, now I can easily average 165. Strength and endurance is also way down. Any ideas or is it just a case of keep at it and get the fitness back?

In your situation I would probably see my local GP and get a referral for some blood work, just to ensure the illness did not leave me anaemic or with some other problem.

Then if all clear back into it.

Update, i was told that it may be an electrolyte imbalance, yesterdays ride had high heart rate, had a glass of salty water this morning and some Pure Sport stuff, rode harder today and no elevated heart rate. I'll ride this week and see how it goes. If no better it's off to the doc.

While I won't make a comments about your specific case, but rather cycling in general, it is normal for HR to be elevated for a given effort level after a taper or period of inactivity. It's also normal for HR (including HRmax) to decline with improved fitness.

Much more likely to be related to the deconditioning due to the period of illness.

Small chance of direct effect on your cardiovascular system (i.e. viral illness causing a mild cardiomyopathy).

Unless you were riding while still pooping murky water several times a day, or you developed some pretty serious kidney dysfunction all of a sudden, it would have zero to do with your electrolytes.

Short note here,
metabolic impairment of the digestive system after acute illness, poisoning, flu etc,
Certainly affects the body's ability to perform well under "duress" - intense exercise.
this is where HR changes might be affected - but it is hard to speculate, every body and condition is different.

Well after a few weeks of watching the HR monitor the fitness is starting to come back and my HR appears to be back to normal while riding. I had a discussion with my GP and he was of the opinion that while food poisoning will produce a gastric response it does affect other organs and muscles, they just don't display the symptoms. He also mentioned that the HR is reliant on the electrical properties of the cells of the heart for stability and these properties can change with even the slightest change in the body's electrolytic balance. Anyway it seems to be back on track now.

Yup... particularly if your K+ or Ca2+ get too high or too low your heart can stop... Keeps some of us in a job.

Unless you had cholera, your HR changes are more likely to have been from, as your GP described, global pathophysiologic effects due to the illness, rather than from a clinically significant electrolyte abnormality.

Glad you're feeling better.