Quick Thought On Hydration

[LittleGreyCat]

Allegedly we normally carry about 4 lbs of weight due to stored glucose.
Roughly 1.25 lbs glucose carried in 2.75 lbs of water IIRC.

So if you have a full glucose store and then go and burn it off that also releases 2.75 lbs water. Which is helpful when exercising.

If you are going hard core(ish) exercise and low carb and you burn off the glucose store faster than your body can replenish it then you quickly burn off 4 lbs of weight but suddenly your reserves of water in your body have gone down as well.

Just struck me as an idle thought when out on a ride today.

 

[tim2000s]

Allegedly we normally carry about 4 lbs of weight due to stored glucose.
Roughly 1.25 lbs glucose carried in 2.75 lbs of water IIRC.

So if you have a full glucose store and then go and burn it off that also releases 2.75 lbs water. Which is helpful when exercising.

If you are going hard core(ish) exercise and low carb and you burn off the glucose store faster than your body can replenish it then you quickly burn off 4 lbs of weight but suddenly your reserves of water in your body have gone down as well.

Just struck me as an idle thought when out on a ride today.

YEs, which is why, when you eat low carb, you find yourself drinking more, and if you undertake anaerobic exercise while low carb, you need loads of water. I usually drink between 3 and 5 litres of water a day when fully low carb.

 

[Lamont D]

This is where you definitely do not want a glucose drink or a thirst quencher.

Water every time and as much as you want.

Even for a non diabetic, a sudden surge of sugar, glucose or carbs can be like having a hyper!

 

[LittleGreyCat]

Yes - covers something I was considering starting a thread about.

When I tested after my last ride (after feeling a little wobbly) I came in at 4.1, heading towards hypo territory.

This was after I had "hit the wall" with about 2 km to go (strong head wind).

In theory I should by then have been running on ketones; which raises the question of what happens when you run out of ketones? Does your body then use more glucose and take you towards a hypo? Should I be thinking about glucose tablets or gel bars as a precautionary measure towards the end of the ride? Or will this mess with the ketosis?

 

[AndBreathe]

Yes - covers something I was considering starting a thread about.

When I tested after my last ride (after feeling a little wobbly) I came in at 4.1, heading towards hypo territory.

This was after I had "hit the wall" with about 2 km to go (strong head wind).

In theory I should by then have been running on ketones; which raises the question of what happens when you run out of ketones? Does your body then use more glucose and take you towards a hypo? Should I be thinking about glucose tablets or gel bars as a precautionary measure towards the end of the ride? Or will this mess with the ketosis?

Personally, since diagnosis, and gaining control the only time I have ever taken anything to bring my numbers up a bit they have been significantly lower than 4.1, and I was going to have to wait a while longer for my next meal. In those circumstances, I have just had a cup of tea, with a splash of milk to see me over the hump (dip); but really it's hunger. I don't eat between meals, and never have.

Clearly those particular options aren't credible on your bike! I'd therefore make a contingency plan to have enough to ensure I could have a drink at that time, and if I felt convinced I needed some calories, I'd have very weak squash or a few nuts.

As T2s; either un-medicated (I've never taken any meds) or on the gentler options, like Metformin, our bodies will usually try to look after us, and mine seems to do pretty well. It's unlikely we will suffer a medically dangerous hypo, and all of the foregoing assume you feel well, if a little fatigued.

Of course, you have to go with your own judgement.

 

[therower]

Yes - covers something I was considering starting a thread about.

When I tested after my last ride (after feeling a little wobbly) I came in at 4.1, heading towards hypo territory.

This was after I had "hit the wall" with about 2 km to go (strong head wind).

In theory I should by then have been running on ketones; which raises the question of what happens when you run out of ketones? Does your body then use more glucose and take you towards a hypo? Should I be thinking about glucose tablets or gel bars as a precautionary measure towards the end of the ride? Or will this mess with the ketosis?

I would be more worried about the 40 ton truck that clears you up than your ketosis. You have a duty to ensure that you safe and competent whilst out on the road.
Feeling a bit wobbly won't cut it at the pearly gates.

 

[LittleGreyCat]

I would be more worried about the 40 ton truck that clears you up than your ketosis. You have a duty to ensure that you safe and competent whilst out on the road.
Feeling a bit wobbly won't cut it at the pearly gates.

Probably a bit of a difference between feeling "a little bit wobbly" and being in a full hypo. However fortunately I've never (to my knowledge) suffered a full hypo.

If I felt really, really bad I would obviously pull in and stop for a rest (which I have done a few times due to extreme tiredness).

 

[LittleGreyCat]

Personally, since diagnosis, and gaining control the only time I have ever taken anything to bring my numbers up a bit they have been significantly lower than 4.1, and I was going to have to wait a while longer for my next meal. In those circumstances, I have just had a cup of tea, with a splash of milk to see me over the hump (dip); but really it's hunger. I don't eat between meals, and never have.

Clearly those particular options aren't credible on your bike! I'd therefore make a contingency plan to have enough to ensure I could have a drink at that time, and if I felt convinced I needed some calories, I'd have very weak squash or a few nuts.

As T2s; either un-medicated (I've never taken any meds) or on the gentler options, like Metformin, our bodies will usually try to look after us, and mine seems to do pretty well. It's unlikely we will suffer a medically dangerous hypo, and all of the foregoing assume you feel well, if a little fatigued.

Of course, you have to go with your own judgement.

Interesting topic all round.

As far as I know you "hit the wall" when all your fuel reserves have been used up and you can't replenish them fast enough; that is, you drink sports drinks and eat energy gels but you are burning stuff off faster than it can get from your gut into your bloodstream then into your muscles. So cramming in more sugar just gets you a delayed sugar rush and doesn't solve the immediate problem.

I would assume that you can therefore logically hit a similar situation when burning fat through ketosis. The conversion of fat and the transfer to the muscles isn't happening fast enough so again you "hit the wall".

If that is true, then you may be in a position where nothing will help and you just have to ease off for a bit.

That in turn raises the question of which is the fastest recovery strategy:

1. Quick small hit of glucose
2. Quick small hit of protein/fat
3. Let the fat burn, baby, burn.

Or perhaps a combination?

As an aside although I think I may have burned off most of my glucose reserves I haven't run out of fat reserves yet.

My current thought is that perhaps if I am burning fat and also creating base line BG through gluconeogenesis a quick very small glucose hit may just pop my BG up a bit but not too far since I only need a little more because I am not burning it as my main fuel source.

The original thought remains, though. If you have switched to burning ketones and you start to run out of ketones, do you start to cut into your minimal remaining glucose? Or does your muscle start to eat itself?

 

[Brunneria]

People in ketosis, or properly 'fat adapted' don't hit 'the wall'. This is why endurance athletes do so well in ketosis. They start and finish the race fuelled by fat.

Voleck and Phinney have an excellent book covering the whole concept of low carb exercise from start to finish (Art and Science of Low Carb Endurance). It is a fascinating read. No need to carb load. No need to top up with carbs throughout the event. No 'wall'. No increased insulin resistance immediately after a hard event. Just plenty of hydration and a constant energy source. Mind you, not so good for sprints or high demand activities. Works best on steadier activities like long distance. I think they mention a figure of 65% output being the optimum.

 

[therower]

Probably a bit of a difference between feeling "a little bit wobbly" and being in a full hypo. However fortunately I've never (to my knowledge) suffered a full hypo.

If I felt really, really bad I would obviously pull in and stop for a rest (which I have done a few times due to extreme tiredness).

That's good news. As diabetics we live close to that hypo line especially when exercising. It doesn't take much to find yourself on the wrong side.
I don't want anyone to have a serious accident that could have been avoided by a bit of sugar.
Excuse my heavy/warped approach but I don't want to see you stop posting.

 

[AndBreathe]

That's good news. As diabetics we live close to that hypo line especially when exercising. It doesn't take much to find yourself on the wrong side.
I don't want anyone to have a serious accident that could have been avoided by a bit of sugar.
Excuse my heavy/warped approach but I don't want to see you stop posting.

I personally believe T1s and T2s have to consider things differently. I consider myself never to have experienced a hypo, although I have evidenced bloods into the 2s, and have 3s pretty much every day.

If we (T2s) are fortunate to have minimal (if any) cell damage and we're still producing adequate levels of natural insulin, we can be fortunate enough to recoverer a good bodily function near to, if not necessarily totally mimicking non-diabetics.

When I go to the very low 3s, I'm usually hungry. When I go well into the 2s, I'm generally verrey hungry and more than ready to eat. I don't "treat a hypo", I have whatever meal is due and usually enjoy it massively.

T1s clearly can need to manage their own regimes very differently, and I consider myself extremely fortunate not to have to learn too much detail in that regard.

 

[AndBreathe]

Interesting topic all round.

As far as I know you "hit the wall" when all your fuel reserves have been used up and you can't replenish them fast enough; that is, you drink sports drinks and eat energy gels but you are burning stuff off faster than it can get from your gut into your bloodstream then into your muscles. So cramming in more sugar just gets you a delayed sugar rush and doesn't solve the immediate problem.

I would assume that you can therefore logically hit a similar situation when burning fat through ketosis. The conversion of fat and the transfer to the muscles isn't happening fast enough so again you "hit the wall".

If that is true, then you may be in a position where nothing will help and you just have to ease off for a bit.

That in turn raises the question of which is the fastest recovery strategy:

1. Quick small hit of glucose
2. Quick small hit of protein/fat
3. Let the fat burn, baby, burn.

Or perhaps a combination?

As an aside although I think I may have burned off most of my glucose reserves I haven't run out of fat reserves yet.

My current thought is that perhaps if I am burning fat and also creating base line BG through gluconeogenesis a quick very small glucose hit may just pop my BG up a bit but not too far since I only need a little more because I am not burning it as my main fuel source.

The original thought remains, though. If you have switched to burning ketones and you start to run out of ketones, do you start to cut into your minimal remaining glucose? Or does your muscle start to eat itself?

Personally, I wouldn't hit the glucose, but that's me and my personal preference.

Assuming you are not undertaking this level of exercise in a fasted state, if the situation becomes your "norm", I would be looking at upping my pre-exercise fuelling, in advance, to give my body good nutrition to work through whilst exercising, and not leaving me feeling the need to take sugary goods onboard.

Tamsin Lewis is a low carb Psychiatrist. She is also a low carbing, professional athlete with a very interesting biog. http://www.sportiedoc.com/about/

Her PHCUK presentation is on this site already, if you haven't come across it already.

Good luck with whichever approach you end up adopting.

 

[LittleGreyCat]

Thanks all.

Came back 4.4 after a slightly shorter and less strenuous ride - no head winds.

I am not eating specifically to fuel for exercise because one aim is to burn more calories than I take on board.

If I ride in the morning it will be a couple of hours after a coffee, butter and cream and I will brunch when I get back.

If I ride in the afternoon I will normally have had a full English or a cheese omelette in the morning as well as the coffee.

I am generally doing all right - just pushing myself so that I am usually knackered at the end of the ride.

As @Brunneria says above, ketone fuelling is best for endurance at 65% output but not for sprints. My route has aspects of interval training (otherwise known as small steep hills with flat bits in between) so I think I am going above the 65% at times. So generally all good but more research needed.

On the subject of hypos I think that they are hard to define by precise BG levels. So people show the symptoms at remarkably high BG levels if their body is used to running at high levels all the time (sometimes called false hypos) and others can run very low without any symptoms.

I think my bit of wobbly was probably because I seem to have brought my BG levels down quite a bit recently so I might be sensitive to being at or below 4. not a real wobble; just a brief "that felt a bit odd" thing for a second or two.

 

[AndBreathe]

Thanks all.

Came back 4.4 after a slightly shorter and less strenuous ride - no head winds.

I am not eating specifically to fuel for exercise because one aim is to burn more calories than I take on board.

If I ride in the morning it will be a couple of hours after a coffee, butter and cream and I will brunch when I get back.

If I ride in the afternoon I will normally have had a full English or a cheese omelette in the morning as well as the coffee.

I am generally doing all right - just pushing myself so that I am usually knackered at the end of the ride.

As @Brunneria says above, ketone fuelling is best for endurance at 65% output but not for sprints. My route has aspects of interval training (otherwise known as small steep hills with flat bits in between) so I think I am going above the 65% at times. So generally all good but more research needed.

On the subject of hypos I think that they are hard to define by precise BG levels. So people show the symptoms at remarkably high BG levels if their body is used to running at high levels all the time (sometimes called false hypos) and others can run very low without any symptoms.

I think my bit of wobbly was probably because I seem to have brought my BG levels down quite a bit recently so I might be sensitive to being at or below 4. not a real wobble; just a brief "that felt a bit odd" thing for a second or two.

Is the wobbly feeling in your legs? Could it be when you step off your bike, after the exertion that your legs have got used to the exertion and your rotational cadence and are protesting to standing or walking? I know when I'm overseas, I try not to use the car to go to the supermarket, unless we need a big shop or the weather is poor. There always seems to be a head wind, in both directions and I have a routine to sort of race myself on the return route. Couple that with a heavy back pack and I can feel like I have my sea legs for a moment or two.

If it's not that for sure, you could try moving your nutrition around a bit to fuel a bit more at the preceding mealtime or just wait and see if your body becomes more accustomed to what you're doing.

 

[LittleGreyCat]

Wobble was between the ears - just a little light headed for a breath or two and then O.K. again.

 

[AndBreathe]

Wobble was between the ears - just a little light headed for a breath or two and then O.K. again.

Were you on your bike, or was it as soon as you stepped off? If the latter, I'm wondering if it might have your body your body objecting to stading up after a long time bent well over.

 

[LittleGreyCat]

Just as I climbed off. However I have ridden a lot and not had this before.

Don't think it was a bent over thing as I change my position quite often.