Cycling UK Forum

853 wrote: ↑15 Apr 2024, 6:32pm

Cowsham wrote: ↑15 Apr 2024, 6:14pm Was it wrong for me to have a fish supper every 30 miles of a 100 mile cycle? ( was only two but they were enormous fish suppers ) then a packet of sandwiches for the last 20 miles. + some chocolate after the sandwiches.

Almost certainly. Protein and fat takes many hours to digest, and if you are pedalling hard body resources will switch from digestion to powering your muscles, meaning it takes even longer.

Of course, if you were pedalling easily then the first fish supper would probably be beneficial to the later stages of your 100 mile cycle ride

After 80 miles and getting *lost on top of a mountain carrying the bike on my shoulder cos of the ruts and foliage. I felt like I had exhausted everything I'd ate. I had for hours run out of water too -- scary cos I'm not usually thirsty and have to remind myself to drink but I was really dry that day and it had been hot. If I'd found another fish supper growing in the bushes I'd have downed that too.

* ( I wasn't lost I knew which direction I needed to go - just couldn't find the way down -- every way I went was blocked by massive bracken or thorn hedges I eventually had to retrace my steps all the way back to way I got up there another 5 miles or so and then go around the mountain -- I found out later that the coastal path, made in the 80's, I was looking for had been washed into the sea a couple of years previous )

Pebble wrote: ↑16 Apr 2024, 9:50am I think I must have a very different metabolism to most, I don't think I have ever bonked, Have worn myself down to a frazzle on many occasions, but I just feel tired and get slower and slower - I can always keep going. My wife is quite different, she will complain of feeling a bit light headed if she hasn't eaten for 3 or 4 hours, she does not cycle but if she did I reckon she would 'bonk'

Even at the moment where I am trying to loose a few pounds, I am fasting twice a week for 24 hours at a time, I don't feel I have any less energy on the days when fasting, don't even feel hungry (I can verge on a psychological break down around meal times in watching my wife eat and all those wonderful smells of cooking), but that is just an overwhelming desire to eat and not hunger. Hunger is very different and something I guess many people have never experienced, takes days to get there and its very different to just wanting to eat. Try it sometime its an interesting experience

I think I'm the same -- just get slower and more exhausted but never 'Bonked' . I did however do the one meal a day diet while training for a weightlifting competition and went from 12 stone to 10 and a quarter stone to enter a lighter weight class. I was surprisingly still very strong and won the competition easily but soon after my strength did wane so I had to put some pounds back on to push the same weights as before. I found losing muscle weight very hard while training. My body was screaming for food.

Have we really got THREE concurrent threads on sugar/fat-burning etc??
And why not? One of the few topics that affects us all to some extent

axel_knutt wrote: ↑16 Apr 2024, 12:50pm
I didn't find any mention of it measuring metabolic rate.

Isn’t Metabolism, as far as us cyclists are interested in it, about converting food to energy? Unless I’ve misunderstood, the ZOE app is all about measuring how that happens, on an individual basis, meal by meal. I’m not sure exactly what units it uses, but what with it having a good look at your blood (and optionally, your poo…) I’m sure it can draw some useful conclusions.

If people should like to see data please see Figure 2 in this manuscript from Flockhart et al in Acta Physiologica (2023)
https://onlinelibrary.wiley.com/doi/ful ... apha.13972
This shows glucose concentrations in blood after an ingestion of glucose, as part of an oral glucose tolerance test (OGTT). Interesting is that they compared endurance athletes versus controls, both at rest and during physical exercise (3 h at 65% of VO2max) and after high intensity interval training (5x4 min at 95% VO2max). The difference between the rest and exercise state shows how much glucose was being utilised over time. It appears to take about 15-30 minutes to start using the ingested glucose.

Paulatic wrote: ↑16 Apr 2024, 10:26am The first 400K I did I was 4lb heavier after the event. The food was excellent
I remember on a 300K in Northumberland being unable to resist a fish supper in Wooler. They sat heavily undigested in my stomach for the rest of the ride back to North Shields. Lesson learnt never to be repeated on an Audax.

What do you estimate as the mass of that meal on the 400K?

Changes in body mass during exercise are often caused by changes in body water. (This is how overhydration was identified in participants in the London Marathon, and was a major step in increasing our understanding of exercise-induced hyponatraemia.)

Jonathan

eileithyia wrote: ↑23 Apr 2018, 7:56am Probably the minutes rest and the psychological boost of knowing something is in the system.
Question do you really NEED the snicker bar or only THINK you need it?

TBH I would be ill if I had something inside my stomach that close to starting a big climb.

A friend used to have this theory; When heading for the bonk stopping and eating makes you feel immediately better, 1. obviously psychological. 2. He thought that eating something triggered the brain/body to know there was some re-fuelling on it's way so the body could release the last bit of reserves of stored glycogen into the system... so your body got a short term boost while the replacement food was digested and absorbed.

tests were done where the subject gargled sugar solution increased performance
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9033104/

I was in the UK for a couple of weeks over Easter and rode most days. 915km in two weeks, with a few rest days.

Most rides were 2-3hrs, generally done at a fairly high intensity. In every instance, the largest hills were sought out and climbed, usually at a fairly hard pace.

Every ride was fueled with two bottles of carb infused water/juice. 1100ml total, 300g dextrose/maltodextrin blend, 200ml fruit juice. So 320g of carbs for each ride, equating to about 120g/hr.

I definitely feel faster and better fueled with that level of carb intake, rather than water. It doesn't come close to covering my overall calorific needs (120g/hr is 480kcal. I usually burn 1000-1200kcal/hr depending on power output) but it stops me depleting my glycogen supplies.

To the original poster, I don't think Snickers is good ride fuel. Far too much fat. Simple carbs and lots of them is the best course of action.

The great thing with Maltodextrin and Dextrose is that they cost almost nothing, and blended with a bit of fruit juice, taste great. It's the cheapest, best tasting and most convenient fuel. The two bottles I usually take with me cost a grand total of about £1.

Question joninsweden. What proportions do you use to mix the dextrose and maltodextrin?

Maltodextrin is a type of carbohydrate, but it undergoes intense processing. It comes in the form of a white powder from rice, corn, wheat, or potato starch. Its makers first cook it, then add acids or enzymes to break it down some more. The final product is a water-soluble white powder with a neutral taste

That sounds healthy and wholesome. May as well get a packet of Capstan Navy Cut.

Several people have commented on the laxative effect of sugars. It's possible that this would vary between different sugars that have equivalent calorific value.

Is anything known about this in practice?

Thanks

Jonathan

Jdsk wrote: ↑17 Apr 2024, 9:59am Several people have commented on the laxative effect of sugars. It's possible that this would vary between different sugars that have equivalent calorific value.

Is anything known about this in practice?

https://www.health.harvard.edu/diseases ... g-diarrhea

The energy gels also contain caffeine, so double whammy

Sweep wrote: ↑17 Apr 2024, 7:29am Question joninsweden. What proportions do you use to mix the dextrose and maltodextrin?

Just 50:50. It's not excessively sweet.

Pebble - I'm sure that maltodextrin isn't the healthiest thing to consume. The rest of my diet is excellent, malto represents about 1-2% of my weekly calorie intake and I honestly dont know how I'd fuel myself as efficiently. I need a crap load of calories to sustain my cycling.

Jon in Sweden wrote: ↑17 Apr 2024, 12:20pm

Sweep wrote: ↑17 Apr 2024, 7:29am Question joninsweden. What proportions do you use to mix the dextrose and maltodextrin?

Just 50:50. It's not excessively sweet.

Pebble - I'm sure that maltodextrin isn't the healthiest thing to consume. The rest of my diet is excellent, malto represents about 1-2% of my weekly calorie intake and I honestly dont know how I'd fuel myself as efficiently. I need a crap load of calories to sustain my cycling.

thanks for info.

and I agree totally with you on using maltodextrin - I already use it for longer tougher rides and think it great - it's gently powered me on many a long ride as of course you sip it in bits as you ride. Better than a stop to stuff yourself I think. Malto is of course used by the food industry as a "filler" but since I eat next to no processed food in my regular diet I don't think this a problem.

I will consider adding dextrose to my bottles - thanks again for info.

Paulatic wrote: ↑16 Apr 2024, 10:26amThe first 400K I did I was 4lb heavier after the event. The food was excellent

If that was all fat gain that would amount to an excess calorie intake of 14,000kcal.

Jdsk wrote: ↑16 Apr 2024, 2:24pm What do you estimate as the mass of that meal on the 400K?

My diet overall weighs 730g per 1000kcal, but it contains a lot of heavy low calorie fruit & veg. Sandwiches which I eat on a ride average 360g/1000kcal, and breaded haddock is 500g/1000kcal.