Low carbing and exercise

[shadwell]

I need some advice from the long term low-carbers like fergus please! I have been low carbing for a while now with great results but have recently started a regular exercise regime and my BS has started rising instead of falling as I expected it to. I tend to swim first thing in the mornings as this is the only time I have available and have found that post-exercise, my BS is rising to 12 - 14 and only comes down very slowly after 3-4 hours, remaining high for the rest of the day. Is this because I don't have enough carbs to provide the energy and my liver is dumping stored glucose into my bloodstream as fuel? I tend to ear breakfast after my swim. Should I be eating beforehand and if so, do I need to start eating more carbs? I'd appreciate advice as I feel better for exercising but don't want to push up my BS levels. Thanks.

 

[fergus]

Hi shadwell,

It's really frustrating when your efforts to exercise are rewarded with a rise in blood sugar, isn't it? :evil:
I know you're t2, whereas I'm t1, so the reasons behind it can be different in each case.
Exercise such as swimming or running will cause a release of stress hormones (adrenaline, cortisol etc.) which cause the liver and muscles to convert glycogen to glucose, just as you said. If I start a run or cycle a few hours after eating, there is no fast acting insulin in my system and the long acting can be insufficient to cover this rise. My solution has been to always eat before I start so I can recruit the fast acting stuff to act against the rise in bs. If I inject a little less, or eat a little more, I can keep my bs pretty stable.
A t2 making a lot of insulin (all do at first) will probably escape this rise, and may instead find their bs falling quite low after exercise. Your experience might suggest that your insulin levels are lower than this.
You could ask your gp or clinic to test your serum insulin levels (an inexpensive test) to see where you are with insulin production levels. Otherwise, the other ways in which your bs will come into line are if they aren't elevated before you start, and if your exercise is sufficiently prolonged to actually start bringing it down again.

I hope that helps?

All the best,

fergus

 

[shadwell]

Thanks Fergus, will certainly ask for the serum insulin test. My BS levels before exercise tend to be about 6 - 7 (my BS has always been higher than I would like first thing in the morning even though it's great the rest of the day). This is why I don't tend to eat before exercising as I don't want to push it any higher, which is ironic as it's happening anyway!

 

[DiabeticSkater]

So without the carbs where do you get your energy?

 

[fergus]

Hi DiabeticSkater,

It's a myth that carbs are essential for energy. Sure, they provide a quick blast of glucose which muscles can use, but the body is perfectly capable of making glucose from protein too - the process known as gluconeogenesis. Also, the oxidation of glucose is only 1 of the 2 main ways in which cellular mitochondria generate energy.The other is the burning of fatty acids, which in fact generates more energy per gram than carbs!
The beauty of the fatty acid cycle is that, for diabetics, energy can be generated without the risk of dangerously rased blood sugar. However, when carbs are the main source of fuel, insulin levels are elevated so that the fatty acid cycle is temporarily suspended - no energy is available from that source until insulin levels fall. This is one of the processes at work when endurance athletes 'hit the wall' but which can be avoided if fatty acid burning is working properly.

All the best,

fergus

 

[DiabeticSkater]

Beleive me I have tried low carb and it did me no good at all. I couldn't do any high end sporting activities whats so ever. Burning out after around 30 minutes. and surely there is a serious risk of ketones?

 

[DiabeticSkater]

Eddie can I ask how old you are? carb requirement do decrease the older you get. But i just dont get how this low carb works. I just don't see it. Maybe some more research is in order. Better get me sen down the uni libray.

 

[DiabeticSkater]

you run at around the same as me. hbac1's of 6% give or take for the last 10 years. well if its working for you thats all good. I take around 150 to 250 grams of carb a day depending on what I'm doing. If its a heavy surf day that can increase even more.