One hour cycling lowers my BG levels by 10% to 20%

I find that cycling lowers my BG more than other exercises such as running, I think it's due to cycling being less intense for me and my heart rate is <80% of maximum, for some reason my heart rate is much higher when running.

I'll not bore you with the background leading up to my current position. We have a treadmill at home and I have been using it routinely to try and retain my previous fitness and get moving again and it's been very useful and important for me. My husband had a hip replacement last year and once given the all-clear by his surgeon, decided he'd like to get cycling again and to cut out a long tale, we ended up with an exercise bike instead.

It ended up rather fortuitous that the machine we wanted wasn't in stock, so we had to wait and in the meantime, went into a large sports outlet and tried the one we'd chosen in there. Jolly glad we did as neither of us could get on with it, the angles were all wrong and we then realised why neither of us had liked the bikes in the gym, preferring cross-trainers etc.

So we selected another model with the pedal axis quite a bit further forward than the seat position - for the first time in 20 years, I'm comfortable on a bike and have totally fallen in love with it. I'm finding that I can push quite hard with inclines and speed and am finding that it has a significant effect on my BGs - much more so than the treadmill. I still love that and use both for different reasons, but for expending energy in a short burst, the bike has been really good for me - I have muscle issues, so find the bike is physically gentler for the same energy expended. I'd like to add a rowing machine next as I always loved that in the gym and think it probably has similar properties for me.

I've found that listening to music whist pedalling automatically gets you into a rhythm and often faster than you intended and I'm doing interval training at the moment; 500m hard, 500m steady etc.

I've always found that Cycling acts very much like weight training when coming into it from fasting, in that I see an increase in bg level as I stress, but if I have any IOB I need to eat carbs, and for the next 8 hours, my insulin sensitivity is significantly increased, so I lower my night time basal if I've cycled home from work, for example.

Went out cycling for the first time after been diagoned 2 months ago. Just a 7 mile cycle over 40 mins as wanted to see what happened...

So, here are my BG levels throughout this morning. I ate 50g of carbs just after the first reading (no insulin) and a further 40g just after the 10:30 reading...

On something like a ten mile gentle cycle ride my bg can drop 25 to 50%. This can happen even when eating 200g + of carbohydrates throughout the day. I also get a large drop after around four hours after the ride. I normally feel a hypo at about 3.8 but after a pedel I can go as low as 2.2 without hypo symptoms. I need approximately 15% less insulin and generally try to balance it out so I do not need to take any. It can be quite a juggling act.

Ian DP said:

I started to do some cycling a few weeks back. Pleasantly surprised to find that if I go out for a one hour cycle my BG levels fall by 10% to 20%. If I cycle for two hours they fall much the same, maybe a little closer to 20%. If I cycle for half an hour I get a fall of around 5% to 10%.

By 10% fall, I mean 10% lower than my normal levels. If I cycle for 1hour for three consecutive days my BG levels will stay 10% to 20% lower than normal. If I stop for a day or two they go back to my normal levels.

I have done some jogging, some gym exercising, walking, swimming. Often these do reduce my BG levels, but nothing like the cycling.
I do cycle a fair bit across country, on a cheap mountain bike. This can be hard work at times, but around half the time it is on road.

Just thought I would share my experience.
Anyone else had the same / different experience?

Click to expand...

Hi ian, yes my bs is now down to a fasting level os 3.8 average and my mid day predinner post dinner(2hrs) are 4.4. 5.3 ,and 5.7 on average this is since doing 10 miles on waking and 10 miles 1 hr post dinner on the exercise bike plus situps x50 am and pm and some light weight training.my weight has dropped from 16st 8lbs sep14 to 13st 10 lbs today. Blood pressure down from 145/90 to 115/65 today hba1c currently 5.2.