heating cold water to body temperature

[Adrian]

Your body has fairly sound instincts as to what it needs;

Syrup sponge and custard might hit the bonkspot rather well though; it's a good mix of fast-burn sugar (4kcal/g), medium-burn (4kcal/g) starch and slow-burn fat (9kcal/g), with some water to help the medicine go down...

In a cafe this meal is mostly comprised of processed flour, saturated fats, sugar and dairy by products with little nutritional value, otherwise known as empty calories and will be depleting the bodies existing vitamin and mineral store to digest it.  so much for sound instincts.

The instinct is OK, just let down in the finer detail.

[Greenbank]

Your body has fairly sound instincts as to what it needs;

Syrup sponge and custard might hit the bonkspot rather well though; it's a good mix of fast-burn sugar (4kcal/g), medium-burn (4kcal/g) starch and slow-burn fat (9kcal/g), with some water to help the medicine go down...

In a cafe this meal is mostly comprised of processed flour, saturated fats, sugar and dairy by products with little nutritional value, otherwise known as empty calories and will be depleting the bodies existing vitamin and mineral store to digest it.  so much for sound instincts.

That's the danger of over-analysing individual dishes or parts of a meal rather than the complete intake over a longer period.

[Jaded]

This is why
Firewood
is not usually in the lists of nutritional content

You've never had  Frugrains, have you?

[mrcharly-YHT]

Your body has fairly sound instincts as to what it needs;

Syrup sponge and custard might hit the bonkspot rather well though; it's a good mix of fast-burn sugar (4kcal/g), medium-burn (4kcal/g) starch and slow-burn fat (9kcal/g), with some water to help the medicine go down...

In a cafe this meal is mostly comprised of processed flour, saturated fats, sugar and dairy by products with little nutritional value, otherwise known as empty calories and will be depleting the bodies existing vitamin and mineral store to digest it.  so much for sound instincts.

Don't be daft. Dietary needs depend on what you are doing. 
Nothing but salad is theoretically nutritious, but won't enable you to keep cycling.  I was once on a very healthy diet, mostly raw veg and salad with some brown rice. Went for an overnight ride, Holmfirth - Holme Moss - Snake Pass, camp in wood, then back home. Man I was in a bad shape when I got home, absolutely craving sugar and carbs.

[Kathy]

Why don't weight loss people just keep themselves a bit cold? Turn off the heating, open a window, drink cold water and lose kilos.

Becos prolonged exposure to cold triggers the body to develop layers of fat as insulation. And if the body in question is still growing, it will grow into a plump round dumpy heat-conserving shape, rather than a lean thin heat-losing shape (I've seen results of studies done on baby piggies).

[inc]

Your body has fairly sound instincts as to what it needs;

Syrup sponge and custard might hit the bonkspot rather well though; it's a good mix of fast-burn sugar (4kcal/g), medium-burn (4kcal/g) starch and slow-burn fat (9kcal/g), with some water to help the medicine go down...

In a cafe this meal is mostly comprised of processed flour, saturated fats, sugar and dairy by products with little nutritional value, otherwise known as empty calories and will be depleting the bodies existing vitamin and mineral store to digest it.  so much for sound instincts.

Don't be daft. Dietary needs depend on what you are doing. 
Nothing but salad is theoretically nutritious, but won't enable you to keep cycling.  I was once on a very healthy diet, mostly raw veg and salad with some brown rice. Went for an overnight ride, Holmfirth - Holme Moss - Snake Pass, camp in wood, then back home. Man I was in a bad shape when I got home, absolutely craving sugar and carbs.

Who said anything about salad or raw veg, I was saying the average cafe meal is lacking in nutrients, mainly because it uses the cheapest ingredients some of which are so processed they have to add vitamins by law, there is more to food than calories. It appears rickets is making a comeback in the UK due to poor nutrition but I doubt many of the kids will be short of calories.  Incidentally craving sugar and carbs is normally due to low blood sugar which in cycling terms is normally due to the inability of your body to metabolise fat fast enough but can be improved with the right  training. 

[hellymedic]

Incidentally craving sugar and carbs is normally due to low blood sugar which in cycling terms is normally due to the inability of your body to metabolise fat fast enough but can be improved with the right  training. 

You can only train your fat-burning so far. Carbs are needed for some 'fast twitch' activities.

[mattc]

Don't be daft. Dietary needs depend on what you are doing. 
Nothing but salad is theoretically nutritious, but won't enable you to keep cycling.  I was once on a very healthy diet, mostly raw veg and salad with some brown rice. Went for an overnight ride, Holmfirth - Holme Moss - Snake Pass, camp in wood, then back home. Man I was in a bad shape when I got home, absolutely craving sugar and carbs.

Who said anything about salad or raw veg, I was saying the average cafe meal is lacking in nutrients, mainly because it uses the cheapest ingredients some of which are so processed they have to add vitamins by law, there is more to food than calories.

The average cyclist won't eat all their meals in the cafe. They can get plenty of nutrients at home (or on the days off the bike).
On a long ride the calorie requirement is what increases the most => eat more carbs/fat at the cafe stop. It's of 2ry importance whether your cake/beans-on-toast are vitamin-rich.

[inc]

The average cyclist won't eat all their meals in the cafe. They can get plenty of nutrients at home (or on the days off the bike).
On a long ride the calorie requirement is what increases the most => eat more carbs/fat at the cafe stop. It's of 2ry importance whether your cake/beans-on-toast are vitamin-rich.

A lot of cyclist are deluding themselves that they need cakes, sponge duff and custard to be able to ride long distances. The average cyclist could do do a lejog on their stored calories. It seems a bit ironic that during exercise most of the blood is diverted to the working muscles and digestion is negligible but if the pace was slow enough to allow digestion the recently eaten  calories are not required as existing fat stores would be mobilised. The old adage " you are what you eat" has more than a ring of truth. Just maintaining a healthy weight by exercise while eating a nutritionally poor diet will still have a negative effect on long term health.

[andygates]

I bonk in an hour.  So, I contest this.  Yes, I have a merry scad of fat, but it doesn't turn into miles.  What am I doing wrong, to be so abnormal?

[pcolbeck]

I bonk in an hour.  So, I contest this.  Yes, I have a merry scad of fat, but it doesn't turn into miles.  What am I doing wrong, to be so abnormal?

Nothing. You just can't convert fat into energy fast enough. No one can. Fat takes much longer to burn than sugar or carbs.

[inc]

I bonk in an hour.  So, I contest this.  Yes, I have a merry scad of fat, but it doesn't turn into miles.  What am I doing wrong, to be so abnormal?

Google "cycle training in a fasted state" 

[Greenbank]

I bonk in an hour.  So, I contest this.  Yes, I have a merry scad of fat, but it doesn't turn into miles.  What am I doing wrong, to be so abnormal?

Going too fast for your fat metabolism.

Bonking is lack of glycogen/carbs/sugars, not fat.

Fat burns in a carbohydrate flame, so if you run out of sugars you're pretty much gone i.e. bonking.

I did the first 160km of LEL on an empty stomach with nothing but water. How? I wasn't going quickly. ~20kph average for 8 hours. (That was after a large amount of preparation for LEL, I'm not saying that anyone could do 8 hours at 20kph now, I couldn't when I first started to get fit again as my lack of fitness and lack of efficient fat metabolism would have had me burning too many carbs at that pace. There are plenty of other riders who can go further and faster without food...)

I doubt I would have lasted an hour if I'd tried to do the very same thing at 30kph.

I've made an effort to improve my fat metabolism by doing lots of miles, often on an empty stomach. The first thing I eat most days is my lunch at midday and I can quite easily go for 24 hours without food and it doesn't really affect me, the hunger soon passes.

[hellymedic]

I bonk in an hour.  So, I contest this.  Yes, I have a merry scad of fat, but it doesn't turn into miles.  What am I doing wrong, to be so abnormal?

Nothing. You just can't convert fat into energy fast enough. No one can. Fat takes much longer to burn than sugar or carbs.

Wot he sed.
You can get your body store of carbs to last longer if you go gently (akin to walking rather than running). Hills, trying to go a bit faster and frequent acceleration will consume your carbs.

[inc]

I bonk in an hour.  So, I contest this.  Yes, I have a merry scad of fat, but it doesn't turn into miles.  What am I doing wrong, to be so abnormal?

Nothing. You just can't convert fat into energy fast enough. No one can. Fat takes much longer to burn than sugar or carbs.

Wot he sed.
You can get your body store of carbs to last longer if you go gently (akin to walking rather than running). Hills, trying to go a bit faster and frequent acceleration will consume your carbs.

ATP is the fuel your body uses which it makes from either glycogen or fatty acids and recycling lactic acid. Converting fatty acids uses more oxygen so requires a slower pace. The brain is a large user of glycogen and it is thought that bonk is more an effect of a mental process triggering a self preservation mode that stops the muscles working. Numerous test have been done showing that fasting ( for days) with little glycogen stored has little effect on exercise performance.

[mrcharly-YHT]

inc, you do know you are lecturing a medic on basic body biochemistry, don't you?

[mattc]

inc, you do know you are lecturing a medic on basic body biochemistry, don't you?

Humble medic by name ...    but at night, she becomes Super Randonneur(se) !!!

[hellymedic]

inc, you do know you are lecturing a medic on basic body biochemistry, don't you?

Humble medic by name ...    but at night, she becomes Super Randonneur(se) !!!

All in the past...
Sports Medicine course Lilleshall 1993
SR 1994-6.
Treated hypothermic squaddies Poole & Salisbury 1996-8 and worked in A&E between 1983 and 2004 as well as helping at various Audax controls.
Maybe I have a vague idea of what powers randonneurs.
Maybe not...

[inc]

inc, you do know you are lecturing a medic on basic body biochemistry, don't you?

I wasn't aware I was lecturing anyone, just adding to the thread, I thought that was the point of a forum.

[mattc]

The brain is a large user of glycogen and it is thought that bonk is more an effect of a mental process triggering a self preservation mode that stops the muscles working.

That's interesting. Of course it may well be that the brain detects this crisis at about the same time the muscles would run out of glycogen anyway!

Numerous test have been done showing that fasting ( for days) with little glycogen stored has little effect on exercise performance.

"Exercise performance" needs careful definition. "power generated for 25mins flat-out" is pretty typical in these studies, and is very different to the kind of steady pace we are talking about. Also, the fat-burning training that I've read about and done does not involve fasting for days.

(I'll assume they weren't measuring max bench-press weight!)

[mrcharly-YHT]

speaking from an unreliable memory, I think it goes a bit like this:

Brain uses about 30% of normal glycogen useage.

Glycogen is stored in muscles, but it's sweet fa - only good for very short period.

Main glycogen store is in liver, but that is released at a steady state, not fast enough to keep up with medium/heavy demands.

You can go at a very low intensity on liver glycogen stores. Up the intensity and it has to come from somewhere else. Conversion from fat is one route and this can be trained. Conversion from carbs in digestive system is another, easier route, but demands more constant feeding.

[hellymedic]

I think nocturnal confusion in long-distance cyclists may be connected with:
Blood sugar
Sleep deprivation
Caffeine consumption
Borderline hypothermia
Darkness
GOK what else...

Whilst this problem usually sorts itself out, it can be dangerous for the sufferer and very worrying for those around. Trying to prevent it is challenging (nigh impossible) but avoiding a low blood sugar (a 'normal' blood sugar which drops as soon as the rider is awheel may be a factor) must be a start.

[mattc]

I did the first 160km of LEL on an empty stomach with nothing but water. How? I wasn't going quickly. ~20kph average for 8 hours. (That was after a large amount of preparation for LEL, I'm not saying that anyone could do 8 hours at 20kph now, I couldn't when I first started to get fit again as my lack of fitness and lack of efficient fat metabolism would have had me burning too many carbs at that pace. There are plenty of other riders who can go further and faster without food...)

I doubt I would have lasted an hour if I'd tried to do the very same thing at 30kph.

I've made an effort to improve my fat metabolism by doing lots of miles, often on an empty stomach. The first thing I eat most days is my lunch at midday and I can quite easily go for 24 hours without food and it doesn't really affect me, the hunger soon passes.

GB: I can well believe that you were able to ride that 160km as described, but did you actually do it on no food? Did you stay at one of SimonP's hotels with no breakfast?

[This is just for my curiousity, nothing to do with answering the OP.]

[inc]

"Exercise performance" needs careful definition. "power generated for 25mins flat-out" is pretty typical in these studies, and is very different to the kind of steady pace we are talking about. Also, the fat-burning training that I've read about and done does not involve fasting for days.

An extract below, 45% VO2 max sounds like  Audax territory

" Aerobic endurance was measured as time to volitional fatigue during a cycle ergometer exercise at 45% VO2max. Measures of VO2, VE, heart rate, and ratings of perceived exertion were obtained prior to and during the cycle exercise. The 3.5 day fast did not influence isometric strength, anaerobic capacity or aerobic endurance.
Influence of a 3.5 day fast on physical performanc... [Eur J Appl Physiol Occup Physiol. 1987] - PubMed result

[mrcharly-YHT]

Inapplicable test

"Aerobic endurance was measured as time to volitional fatigue during a cycle ergometer exercise at 45% VO2max. "

Audax requires time to fatigue to be infinite (or of timespan measured in more than 24hours).  Ergo not testing same thing.