You carry more, so you eat more ... so have to carry more.

[Bearbonesnorm]

I've just re-read an article by Eddy Meecham in which he compares his present ultralite kit to his previous lightweight kit. He does this by going out with his 'old' kit for the first time in a few years ... now, his 'old' gear certainly isn't what you'd call heavy by general backpacking standards, tipping the scales at 10kg inc' food but the ultralite kit he now uses weighs around half that figure.

The thing that struck me as most interesting wasn't the fact that his 'old' stuff was still surprisingly good or that it was less faff to use ... it was the effect carrying it had. To sustain the increased workload he had to consume twice as many calories while carrying 'old' kit than he would, had he taken his ultralite stuff. Unless you're going to survive on blocks of lard then having to consume more calories must mean having to carry more food to some degree ... I can see a vicious circle forming here.

As 'cyclists' I'm just wondering how much the same thing effects us. I'm not sure we suffer in quite the same way as someone with all their stuff on their back but I'm sure it must be similar ... the effects of riding a loaded bike for the very first time must testify to that

Anyone?

[d45yth]

I suppose a lot of it depends on the route you're doing and hard you push yourself...you can still get rest on a bike whilst still moving, on certain parts anyway.

The last trip I set off to do, I wasn't sure how far I'd be able to cover on the first day or how much I'd need to eat. I just concentrated on the climbs, taking it fairly easy on the flats and descents. I was having a snack every half hour and drinking plenty too. I'd had my breakfast and stopped for a light lunch. I ended up riding the whole route in less than a day, I needn't have took my bikepacking gear! The point of me mentioning this is, if my setup weighed twice as much, would I have eaten more? I don't think so, I would just have been slower. I think when you're exerting yourself, eating more (than 400cals/hr) would have a detrimental effect. You probably wouldn't be able to stomach it and/or it would slow you down even more.

I think most folk don't plan their daily rations around how much they're carrying either. Even if you were under-eating slightly, you'd get away with it for a couple days. It would only be on extended trips where it would start to effect you.

Warning, the above may be a load of nonsense! I know there's a lot more folk on here who know a lot more about nutrition than me...they've put the miles in/done the trips to prove it!

[Cheeky Monkey]

Whilst I get the theory I'm sceptical it'd really be discernible. There's such a large number of variables that would affect calorie consumption, effort being one but also temperature, altitude etc.

Whatever, I've got substantial excess stores so a couple of kilos of gear here or there isn't going to make much impression

[Bearbonesnorm]

I suppose on one hand it's really quite complicated and on the other, very simple ... riding with a heavier load requires more effort ... that increase in effort requires more calories to fuel it ... more calories require more food.

I think everyones own 'make up' must also play a big part. I've ridden with people who seem to require 2-3 times more food than I do and others who need to eat something every half hour to keep the fires fair chuffed. I often wonder ('cos I've nothing better to think about) whether your own bodies ability to fuel itself by using fat stores rather than a regular intake of carbs, plays a big part ... if you can readily / easily burn fat, then as effort increases you just burn more of it, without the need for extra food?

[d45yth]

I think you're right about everyones own 'make up'. I weigh 10 stone and haven't an ounce of fat on me. Even with a large breakfast, I would struggle towards the end of a hard 3 hour ride without extra fuel. Others I ride with don't seem to have this problem. It isn't like I don't eat enough either, I eat more in a day than most riders I know. I've even tried eating snacks between all meals and having weight-gain at night. After a few months of this I still weighed the same!

I suppose on one hand it's really quite complicated and on the other, very simple ... riding with a heavier load requires more effort ... that increase in effort requires more calories to fuel it ... more calories require more food.

I've tried writing a more in depth version of this but it ended up being that long winded I was confusing myself! It takes someone more articulate than me to explain it. If you were using a mechanical engine as the basis, it would be easier. Even that though would choke on too much fuel and could overheat or be overcome if under-powered or overworked. When you throw in humans, bikes, gears, etc, the varibles soon start to stack up. Another would be whether you were trying to travel at the same speed, apart from steep hills, you could travel slower and not use more energy. To try and travel at the same speed wouldn't be able to be sustained, unless you weren't going at your maximum sustainable speed in the first place...taking in more fuel isn't exactly the answer.
Those who exercise hard all day, for multiple days will know that it's impossible to take on more calories than what they've burned too. Look at those who've done the TDR or Tour de France.

Anyway, enough wittering from me. You can probably tell I'm wired on too much caffeine!

[Cheeky Monkey]

MIke Stroud wrote a good book on this subject (ish):

http://www.amazon.co.uk/Survival-Fittes ... 453&sr=1-1

Got some quite good credentials having done a bunch of expeditions with Ranulph Fiennes.

[pedalhead]

I've been experimenting with a low carb diet recently, just to try & get my body trained to burn fat better. I've definitely noticed an improvement in general energy levels (no more peaks & troughs), and on low intensity rides I find I need to eat less. I still feel that I need simple sugars on more intense rides though.