Fructose diet for multi-day event?

Lumen

Amongst other goals this year, I've been persuaded to do the Race Around Ireland in a team of four.

This involves riding about 6 hours/130km a day for four days in a row, broken into shorter stints, with not much sleep.

My biggest concern is my lack of time and motivation to do months of long, slow training sessions as suggested in the 600km randonee plan in the Long Distance Cyclists Handbook. I can probably manage one or two 120km rides a week in addition to racing and speed work on the turbo, but that's about it.

So, I'm looking for shortcuts.

Apparently whilst both muscle and liver glycogen are used in aerobic exercise, liver glycogen stores are the determining factor for onset of fatigue.

I found this study on rats, which found:

Thirty-six rats (8 wk old) were divided into two dietary groups and were fed with a control (chow) diet or fructose diet (containing 20% fructose) for 12 wk. During this period, one-half of the rats in each dietary group were trained by using a motor-driven treadmill (running speed of 25 m/min and duration of 90 min/day, 5 days/wk). The liver glycogen was increased by intake of a fructose diet and exercise training, and the content was in the following order: control-diet and sedentary rats < fructose-diet and sedentary rats <= control-diet and trained rats < fructose-diet and trained rats in the ratio of 1:3.4:3.6:5.0. The glycogen content in gastrocnemius muscle showed the same trend as that in liver; the ratio was 1:1.3:1.3:1.6. These results indicate that both long-term intake of the fructose diet and exercise training synergistically increased glycogen in both tissues.

So basically, eating 20% fructose and doing no training gives about the same liver glycogen boost (3.4x) as training and eating a normal diet (3.6x), but doing both gives the maximum effect (5x).

Wikipedia says:

"When fructose reaches the liver," says Dr. William J. Whelan, a biochemist at the University of Miami School of Medicine, "the liver goes bananas and stops everything else to metabolize the fructose." Eating fructose instead of glucose results in lower circulating insulin and leptin levels, and higher of ghrelin levels after the meal.[55] Since leptin and insulin decrease appetite and ghrelin increases appetite, some researchers suspect that eating large amounts of fructose increases the likelihood of weight gain.[56]

Excessive fructose consumption is also believed to contribute to the development of non-alcoholic fatty liver disease.[57]

So eating fructose might boost performance in the short term, but may kill my liver in the longer term.

Obviously I'm not so obsessed with cycling as to risk my health, but I wondered whether anyone more knowledgable could comment on the use of fructose in training for endurance athletics.

Is it worth introducing fructose into the diet during build up (e.g. the three months before the event)?

Should we consider using fructose for recovery during the event?

Is glycogen storage capacity really that important for a four day event, or is fat burning significantly trainable? Should we just stuff our faces with pizza at every opportunity?

niceonetom

also

https://www.youtube.com/watch?v=hILqMGb2u2w

Raam

Lumen wrote: »

Should we just stuff our faces with pizza at every opportunity?

Yes.

victorcarrera

I think many of the preferred food types that long distance and competitive cyclists eat are high in fructose anyway.
If the following link is to be believed, avoiding consuming high percentage fructose foods would be very difficult.
High fructose foods

Nice to know that a coke and apple dippers in McDonalds is a great way to top up though.

DirkVoodoo

Catsup, Ketchup, catsup, ketchup....

Are you here to help with my catsup problem?

Chips Lovell

I like the way Lumen can turn any cycling challenge into a science experiment.

DirkVoodoo

el tonto wrote: »

I like the way Lumen can turn any cycling challenge into a science experiment.

He would be a good host for that "Braniac:Science Abuse" show, certainly better than that ex-big brother guy. The experiments might go a bit too far though.

Chips Lovell

DirkVoodoo wrote: »

He would be a good host for that "Braniac:Science Abuse" show, certainly better than that ex-big brother guy. The experiments might go a bit too far though.

I'm not sure if I'd trust him blowing up caravans though.

rottenhat

Lumen wrote: »

Amongst other goals this year, I've been persuaded to do the Race Around Ireland in a team of four.

This involves riding about 6 hours/130km a day for four days in a row, broken into shorter stints, with not much sleep.

My biggest concern is my lack of time and motivation to do months of long, slow training sessions as suggested in the 600km randonee plan in the Long Distance Cyclists Handbook. I can probably manage one or two 120km rides a week in addition to racing and speed work on the turbo, but that's about it.

You think you'd need to do more than a couple of 120km rides a week, on top of racing and speed work? To do 6 hours a day at an average pace of 22km/h? I don't think the training plan for a 600 in the book would be at all appropriate for that - you won't even be doing 600km over the course of the entire event, much less in the 40 hours that you have for it on an audax. I think you'll be all right without engaging in bizarre modifications to your diet.

el tel

I think the study should be repeated with adult rats on static bikes before reaching any conclusions

blorg

Lumen wrote: »

about 6 hours/130km a day for four days in a row

More like 190-200km a day for under three days! Remember the faster we do it the quicker it will be over.

Lumen

blorg wrote: »

More like 190-200km a day for under three days! Remember the faster we do it the quicker it will be over.

I don't think that I can cycle at 35kph for six hours a day.

I can barely cycle at 35kph for one hour.

Bonking seems likely.

el tel

blorg wrote: »

More like 190-200km a day for under three days! Remember the faster we do it the quicker it will be over.

C'mon, spill the beans - who's also in the team? Fair play to yous, very hard core event. I'm wincing at the mere though of doing the Tour Of The Glens never mind the RAI

blorg

Lumen wrote: »

I don't think that I can cycle at 35kph for six hours a day.

I can barely cycle at 35kph for one hour.

Bonking seems likely.

190km each per day gives ~31.5km/h average. This was the speed of the winning team last year.

blorg

el tel wrote: »

C'mon, spill the beans - who's also in the team? Fair play to yous, very hard core event. I'm wincing at the mere though of doing the Tour Of The Glens never mind the RAI

Raam
aidan.doyle
blorg
Lumen

Lumen

blorg wrote: »

190km each per day gives ~31.5km/h average. This was the speed of the winning team last year.

Ah, right. I was taking 4x200km a day (giving 33.3kph) and leaving 3 minutes per hour for changeovers (giving 35kph).

Are we trying to win it now?

Raam

3 minutes for a changeover?

Lumen

Raam wrote: »

3 minutes for a changeover?

Arbitrary. Point is, small stoppages have a big impact on average speed.

And we'll get lost.

blorg

Should be able to do changeovers with no delay whatsoever, you overlap the riders and the one leaving does so when the one starting is up to speed.

Regarding getting lost, I would be planning on GPS.

rottenhat

blorg wrote: »

Regarding getting lost, I would be planning on GPS.

This translates as taking multiple wrong turns when Blorg does not read the GPS quickly enough, with a possible side order of running into the back of a car.

leftism

Lumen wrote: »

Should we just stuff our faces with pizza at every opportunity?

Not sure if you've heard of "fat priming"?

Stuff yourself full of burgers, chips, pizza, cheese, anything fatty for about 4 weeks before the race. Then switch to purely carb diet in the last 5 days and carbo load as normal.

This method has been shown to significantly delay glycogen depletion compared to a standard carbo loading regime. The reason being is standard carbo loading and a predominantly carb based diet promotes carbohydrate utilization as the primary energy source. As a result, your body will transcribe more carbohydrate oxidating enzymes within the muscles. The net result is faster utilization of your glycogen stores during exercise since the body is primed for carbohydrate metabolism.

By "fat priming" in the final month of training, you are exposing your body to large quantities of fatty acids in your diet and the net result is an increased transcription of fat oxidative enzymes. Thus the body has now been primed for fat oxidation, and you significantly slow down your rate of glycogen depletion during the race.

With regards to a multi-day event, replenishment of glycogen stores will be very important. Ingestion of protein-carb complexes directly after exercise significantly improves glycogen replenishment compared to pure carbohydrate replenishment. Check out any papers by Ivy et al. on post-exercise glycogen restoration. By adding protein into the mix immediately post-exercise, you can improve your glycogen restoration (and as a result your recovery capacity) by as much as 20% compared to pure carb recovery.

Just a few ideas. You've probably heard a lot of it before anyways, but good luck with this event! Sounds like a gruelling schedule!

victorcarrera

This is not my type of event so I'm wondering if there is any advantage to scheduling the changeovers to allocate riders with different abilities to parts of the course that suit them, or allocate on an equal time share basis.
My guess is that there may be a significant gain in starting your best climber at the bottom of a long climb or hilly section go flat out and swap again at the top, rather than have a tired rolleur face into the same climb.

Lumen

victorcarrera wrote: »

This is not my type of event so I'm wondering if there is any advantage to scheduling the changeovers to allocate riders with different abilities to parts of the course that suit them, or allocate on an equal time share basis.
My guess is that there may be a significant gain in starting your best climber at the bottom of a long climb or hilly section go flat out and swap again at the top, rather than have a tired rolleur face into the same climb.

I'm thinking that Raam can do the climbs and I'll do the descents.

Seems fair enough.

ROK ON

This race last year passed by the front door of my house.
If I am available I would be happy to provide support/bed/shower/meal for the kerry leg.
Best of luck lads.

blorg

Really appreciate that ROK_ON, I think we will take your advice on the baby thread with regard to taking you up on that

Raam

Lumen wrote: »

I'm thinking that Raam can do the climbs and I'll do the descents.

Seems fair enough.

Fine by me. I say that now...

aidandoyle

You do know that we will hold you to that Mr RAAM...

RAI have just released the route details, so we can start strategising as of right now. I must say that I like this idea of having the riders ride the sections which best suit their ability as opposed to blind swapping after an arbitrary time has passed. Thats grand, RAAM does the uphills, Lumen does the downhills, Blorg does all the flat stuff and I will perform the role of chief fructose supplier ;o).