How does keto work for you doing exercise? Do you have a routine or adaptation that works for you?
I ask because I’ve tried keto a couple of times and usually gave up within a few weeks because it was incompatible with (energetic) cycling. The difference with huge - I was crawling up hills that usually I’d barely notice.
I assume it’s because I’m very carb-adapted and/or my level of exercise intensity is too high for fat-burning anyway, but I’ve not found much about this online. (And here and there, I’ve found mention, even on the most vehemently anti-carb websites, of athletes needing supplemental carbs to exercise efficiently.)
I do intense exercise at least 120 mins / day including running, HIIT, calisthenics but no heavy weights. No cycling here unfortunately as the roads are terrible, drivers are nuts, just not safe, but I used to ride centuries when living elsewhere so have some idea of how demanding that can be. I used to take gels and nuuns in bottle etc. Not sure how you'd go with hitting carbs before a ride but you can always try and then do a ketone urine test after the ride to see if you're still in ketosis. Maybe it works.
The main issue I encountered along the way where resolved by:
1) Supplementing basic electrolytes (sugar free).
This helped with cramps and pains that I got once starting out.
2) Getting the right number of calories per day (how much I burn in the day +/- 150 calories).
I check in on this with data from fitness band connected to a nutrition app. A deficit over 150 calories and I definitely have noticeable side effects, mood, focus etc. But for me it's not as severe once in ketosis as it is on regular diet.
3) Ensuring the right macros
I was shocked how much fat I had to eat at first. I'd always thought keto was closer to a high protein diet. Getting quality fats was key. Tallow, Ghee, MCT oil, avocado, olives etc. For snack sometimes I take a tablespoon of feta marinated in olive oil and herbs.
My goal in switching was about freeing myself from sugar addiction. But the side benefit is I now exercise less (120 mins down from 160 mins). Yet in these last ~3 months I went from 90kg (198lbs) to 85kg (187lbs), the lightest and most energetic I've been for over a decade.
It's been great for me so far, but recognize it's not for everyone.
You might find Dr. Dominic D'Agostino's websites or podcasts with various people instructive. He gained prominence after being amplified on an episode of The Joe Rogan Experience, but long before that, he was developing ketogenic solutions for the ONF (Office of Naval Research), specifically using ketones and the ketogenic diet to allow SEALs to remain submerged for longer periods due to a synergistic effect with ketones and oxygen metabolism in the brain.
He has specifically discussed how to solve the problem you had, but it's buried in one of his podcasts somewhere, and I haven't listened to them in ages.
I’ve done marathon training while on keto. Obviously a much different power output need to cycling so take this with a grain of salt… it took me about a month to adjust. That first month had me really struggling to even do 50% of the training distance I was used to. And then it all just clicked suddenly. Not like I started improving again, literally went from struggling to straight back to race performance. One day I was struggling to do a slow 10km. A few days later I ran 35km near race pace. It was a very weird experience.
I’ve been out of keto and training habit for a few months now (recovering from surgery) but I also seem to recall having a different sense of energy awareness while running. Like somewhere between the 30-40min range of a run I’d suddenly feel more awake and like I’d just had a coffee.
As someone who both runs and bikes, I don't think Marathon vs Cycling is that different. You just need to compare similar efforts, are you pushing a marathon to hit 2:30 or whatever? Then compare to biking a shorter crit. Or if you are doing a 5:00 marathon, compare to a century.
Marathon running is typically at a steady pace with only minor variations in the energy output needed. Except for time trials, cycling power is a lot more variable. A cyclist in a road race might be cruising along in the peloton for most of the race but then have to sprint near maximum power to attack or chase several times at unpredictable intervals. So training plans focused on one sport or the other end up looking significantly different in terms of target heart rate zones or perceived exertion, even when training for races of similar duration.
More like a low 3:00 time for me these days (to answer OP). Which as you’ve said is mostly a product of a very steady pace. Hopefully only a 3% variance of my cadence over the distance. Pace may change a little based on the gradient. But it’s a pretty consistent power output for 3hrs.
I’m basing my incredibly limited cycling knowledge on listening to my friends talk about their weekend rides. Certainly seems like a lot more variance with power demands for the climbs, slip streaming on the descents, and then the variance from peloton positioning when they’re in the long flat sections along the coast.
Here's a good example from when Sepp Kuss won Stage 15 of the 2021 Tour de France. It was a massive effort over 5 hours but his power output varied a lot at various points.
I ask because I’ve tried keto a couple of times and usually gave up within a few weeks because it was incompatible with (energetic) cycling. The difference with huge - I was crawling up hills that usually I’d barely notice.
I assume it’s because I’m very carb-adapted and/or my level of exercise intensity is too high for fat-burning anyway, but I’ve not found much about this online. (And here and there, I’ve found mention, even on the most vehemently anti-carb websites, of athletes needing supplemental carbs to exercise efficiently.)