I have some experience that might help. Similar to Bbt67, but never was ill just less time overall on it. I really enjoyed being on Keto while cycling. As a disclaimer, i did it for 3 months hard-core. I managed macros, electrolytes, vegetable intake and little to no stevia/monk fruit… really easy to maintain and no desire for sweets. I went from 84kg to 78kg in this period and FTP increased 3%. (4.1 w/kg at the time)
As the podcast points out, there is an issue with longer high intensity workouts, however increases avg power over longer endurance rides. Here are a few scenarios i found on the bike.
Regular weekend 3 hour climbing rides:
I’d have enough energy for 1-2 early ride sprints with full effort. I didn’t feel there was any loss in performance and finished as expected for most. After glycogen depleted (it is noticeable) there was nothing in the tank for high efforts… HOWEVER, I found a sweet spot in performance around 135bpm (I’m 30) that i could ride all day at even after the earlier exhaustion. Yes, in this case HR is much more the limiting factor than power (you can read up on the science of optimal fat burning zones) I couldn’t push past the threshold, but had no reason to go less. Contrary to what Coach Chad said in the podcast, i found some sugars can be added during workouts to improve performance, like jet fuel, just it doesn’t take much nor can your body handle much and it won’t magically bring back your regular performance for the ride.
1x/mo 160km ride:
I had my fastest time for this route and also had some “Show-off” pulls for some randos we passed on the route. I had no body aces such as back, hands, neck. My mate who usually rides faster was struggling at the pace and i pulled most of the last 60km back while smiling and joking… we were all weirded out (maybe the mates more pissed because i felt so good) For fuel, I had 2x string cheese, a pack of fatty ham and other then sugar free sodium, potassium, magnesium, calcium + aojiru mix, i did have 1x500ml diluted Sports drink (Aquarius) with plenty of sugar over the course of the ride. Legs were tired after of course, but hunger pangs were just not so bad that i could manage the food intake after.
Sprints and CX races:
Did one CX race. Its only 30 minutes, but there was no sluggishness, lack of power or any sense of a difference in performance in concentration. I did want to do more races to see if this was special case, but I promised myself only 3mo and the timeline became more important than staying on it.
What i found:
- It isn’t as easy as just upping your fat content, watch protein levels and eat your damn salted veggies.
- Endurance rides were more efficient from budget and calorie intake
- <30 minutes of intense exercise showed no noticeable drop in performance
- There is a sweet spot “fat burning zone” which you build your
- General dieting afterwards was much easier
- Neutral mood throughout day regardless of meal times… you may hate your less productive colleagues more.
- Best HDL/LDL readings of my entire life.
- Everyone thinks your crazy, so make sure to be prepared with the science to justify your plate of mayo.
- You’ll learn a lot about your body, whether you have sensitivities towards food groups or just how to properly fuel.
- When you cycle off, you will gain some weight from water retention. Don’t worry, it is easier to go back on the next time
- There is no more celebratory beer after rides/ races… bring your gin and give shit to your uncivilized mates as you weep inside.
- You have nobody to talk with about it and there is little studies to support endurance use to help you manage it.
- You desperately need: sodium, potassium, magnesium, calcium… more than you can expect so add salt to everything… everything
- You find even after being on keto, longer ride fueling isn’t such of an issue and your body seems to better manage switching the energy source. It isn’t instant, but it is noticeable.
I hope that helps, I try to fit 3months of KD in during the year. I find during your base period is the most productive time and use for it and mentally just easier to periodize that way. After that you can try CKD (cyclical) if your able to be disciplined your body has been properly adapted in the past. If you like to do more centuries or Randonneuring, its probably for you.