Cycling and Fasting (5/2 & 16/8)

Over the last couple of years I've lost almost 15kg, most of it fat, using time-restricted eating and cutting my carb consumption. It really didn't affect my cycling at all.

In January I signed up to a training programme with a cycling coach. Inevitably, the nutrition advice was to dramatically up the carbs on training days. As a result, I gained 1.8kg in a few days plus the usual stomach problems and heart rate spikes that go with carb consumption. After four weeks of half-killing myself on the turbo, my FTP had DROPPED 10%. To be fair, the coach gave me a full refund but personally I think the benefits of carb fuelling are oversold, especially if you're a bog standard club cyclist and not in the pro peleton.

I was essentially doing a 16/8 for a couple of years before Covid and had was fairly satisfied with it. I got to probably the lightest and fittest I'd been in decades and was able to do multi-hour rides (longest I think was 5-1/2 hours/120 odd km) As others have said, endurance is fine, but my pace fell way off. I lapsed in the middle of lockdowns and have never really managed to get back to where I was - I'm failing miserably to shift the Christmas timber at the momen - though my fitness is improving

I have been commuting 'on empty' for years now. I don't know how long your ride is but an hour or more is fine, just try to keep the intensity down if possible so that you're not using up your carb stores and making yourself more hungry.

I used to go out for longer rides with no brekkie and limited in-ride food but found I was ravenous when I got home, it didn't really work. It seems that the whole keto/fasted thing is of limited value if you're trying to train with any intensity - lots of advice around nowadays to 'carb up', to 'fuel for the work required' (i.e. before & during, e.g. Cycling Weekly).

When you eat can help promote weight loss but IMHO more important is what you eat.

I follow an intermittent fasting strategy on a regular basis, usually 18/6, so 2 meals a day, around 1PM and 7PM while doing all sorts of high intensity sports or work.

I still consume as many calories as I would do eating more often, I just find that a 2 meal a day strategy makes me far more able to concentrate fully during the mornings, rather than have a slump mid morning as breakfast is digested.

I've got a 7 day fast planned for the end of the month, a first for me, having done a weekend fast, once a month for the last year now.

If you want some scientific lead facts about intermittent fasting, when and how to go about it, I suggest you listen to

https://www.youtube.com/watch?v=9tRohh0gErM&ab_channel=AndrewHuberman

https://www.youtube.com/watch?v=7R3-3HR6-u4&ab_channel=AndrewHuberman

I ride fasted regularly, and have even bike commuted (9 miles each way) during a 24+ hour fast. An hour ride, maybe two, is no problem, and if you're truly keto adapted and can limit the effort, you can do it for 6+ hours.

The only trouble I've run into was:

• Keeping up with a fast group while fasted. After about four hours I was really starting to bonk. I was riding above what I could sustain from converting fats to ketones. Stopping for a snack (mostly) fixed it.
• If it's hot, and you're not eating, you need adequate electrolytes in your drink for a 2+ hour ride. I thought I was getting enough from drinking sports drinks, but with heavy sweating they have less than half the electrolytes needed. I should have bought the packet of crisps I was craving when we stopped at a shop.

My current strategy if riding fasted is to still carry carbs and, in hotter weather, electrolytes, and either start consuming them after 2-2½ hours if it's a high effort ride, or just keep them for as needed if riding alone or with a slower group.

Will Missus Squirrel know or care if you're eating Percy Pigs on longer rides? They're not going to your waistline if they're able to go straight into your pedals.

Tried riding on a 20/4 fasting plan: bonk city!
That's 20 hours of no calorific intake eating only between 17-21:00; I'm a courier so early to bed, early to rise.