Fasted exercise during lockdown - result!

[stuffedolive]

I've often mixed a bit of fasted exercise into my week, but as i'm a bit creaky most mornings i have just limited it to Saturday morning's 5km parkrun.

Lockdown changed all this.

As we were initially allowed out for exercise once per day avoiding others, I (accompanied by the other half) started going for jogs at 8am, every day to avoid people. These runs were initially for about an hour but got longer as the weeks went on. So since late March some form of fasted exercise, from an hour's run to 10 miles (3 hours) walking, has been a regular feature -with only had 4 or 5 days off. I have a delayed breakfast when I get back then eat lunch etc as normal.

I have always been very irregular with taking BS readings. I have tended to do a lot for a couple of weeks than hardly any for a month or two. The pattern has always been the same, high (7ish) morning BS then bouncing around the 6's all day long on a LCHF diet but with mainly evening exercise. Carbs push it up but I have largely avoided very high (over 10) readings.

A few weeks into this latest fasted exercise regime I randomly tested an got my lowest ever reading (4.6). I have since tested on numerous occasions and seem to be getting much lower numbers than before lockdown - and I am probably eating more carbs (my wife has been making home baked bread!). My weight has stayed the same.

I appreciate that this amount of fasted exercise is not recommended by sports nutritionists, who say that it will negatively impact performance and lower immunity. However the impact on my BS levels seems, on the face of it, to be entirely positive.

Has anyone else had this experience? Or cast any light onto why this may have happened?

 

[sno0opy]

Sorry i have been away from the forum and only just read this.

Out of interest, is the fasting part new, or the excersise?

I dont fast, but i do a similar level of exercise and have found my figures crashed down after i started. Active muscles have a lower resistance to insulin as they crave the glucose to feed them. I find (i dont do it but i have tested) if im running allot in the proceeding weeks i can eat anything, any level of carbs i dont get a rise. If i dont exercise (i was injured) my levels start climbing again.

If its just more exercise your doing now rather then specifically fasted exercise it could be that more then the fasted part. Although i would guess fasted exercise will drain all the glucose out of your system with nothing to replace it so i would expect it would have a more pronounced effect then exercise post fasting.

 

[stuffedolive]

Sorry i have been away from the forum and only just read this.

Out of interest, is the fasting part new, or the excersise?
.

Neither is new. Its the combination on a regular basis.
I've always done a lot of exercise (but not first thing in the morning) and I often have either a delayed breakfast or even a weekly 24 hour fast. However, exercising early morning before breakfast day after day is new.
hth

 

[sno0opy]

fairynuff, its interesting if you have seen such drop!

Now i think about it i may well do this already, just not on purpose. I generally go for a run (or the gym when open) first thing in the morning before work so while not a true fast i suppose i have been doing the same.

Just got my latest HBA1C back at 30 this morning, good times given i have been eating more carbs during lockdown!

 

[Goonergal]

Great stuff @stuffedolive

My exercise is almost always fasted and it seems to improve rather than hinder performance. Definitely recommend it!

 

[Brunneria]

It was your reading of 4.6 that caught my attention.
That is exactly the reading that I go down to, at my lowest, with solid, sustained exercise - just as you are doing.

For me, it is a very simple thing, although it took me a while, and a libre, to work out what was happening.

I live the whole of my life with a certain level of insulin resistance (I think most T2 types do, though it varies for each of us). So our usual readings are taken before and after food, or fbg, and include the fact that insulin resistance (IR) makes the reading a bit higher than it would be without the IR.

Then along comes a nice bout of sustained exercise. We use up glycogen stores in the muscles, and liver, we burn glucose for energy, our muscles get loose and warm and efficient - and our IR drops - and we start to get the bg readings that our bodies would have the rest of the time, if the IR didn't bob us back up to the higher readings, like a cork rising to the water surface.

Does that make sense?

Exercise is well known for reducing IR.
For me, that means that I start exercise on (for me) a typical 6.2, do enough exercise to reduce the IR, drop sharply to 4.6 (always 4.6! lol), then flatline there until one of two things happen; either I eat something with a few g of carbs, or the effect of the exercise fades slowly, and my bg bobs back up to its usual IR levels.

Probably worth noting that this only happens when you exercise enough for it to happen, and the fitter you get, the more exercise is needed for the same return. I have never found the right sustainable balance between exercise and IR reduction. I just get fitter, my body stops dropping the IR so much, and the fitter I get the more exercise is needed for the same effect. Rather disappointing, really. And it is the reason why I never believe the hype that exercise is the Cure All for T2s with IR.

Hope that helps.

 

[NicoleC1971]

I'd say it is likely that exercise improved your IR because you've gained some muscle thus your own body is sensitised to your insulin hence your lovely bgs.
As to the tired advice to eat before exercise I'd say that if you are feeling fine and energised then why not continue fasted til lunch? You body will adapt to burning fat like this and you are already low carb. Many endurance runners go for far longer than this merely using the fuel in their muscles and then their fat supplies (we all wear thousands of those calories after all!).
Hope you can continue though might be good to have a plan for dark and wet Autumn/Winter days!