Anyone here on the keto diet while they are training?

I can't imagine that this would be a good idea for anyone riding copious amounts of miles. There may be lots of health benefits to a ketogenic diet, but if you're training for an aerobic event like endurance cycling you're going to need carbohydrates. While I'm sure there are people who do it, it would be far from optimal.

You have to be absolutely clear on the totality of your goals and diet and training and exactly how each part fits together into the whole.

So let's start with all of your goals from training, plus where you are now wrt each goal, plus your training plan / time horizon.

I did Keto a few years back. Worked fine for me. I was doing centuries, 200k's, etc. These days I've shifted from keto to acknowledging there are plenty of carb sources that are beneficial, however I'm of the crowd that considers sugar (specifically, added and/or excess) the root of most issues.

If you're training for performance, then this would not be the diet to follow.

Depends on:

current power
current weight
current fitness
power goal
weight goal
fitness goal
time frame

Example: cut weight while building base. May be great application for keto.

Example: building power to peak for long rides / races. Keto may be counter productive.

I do low carb, not true Keto, stay under 100g of carbs daily. With that being said, I did <30 net grams daily and tried to ride. Did a 20 mile ride and bonked hard enough to rethink what I was doing. On <100 net grams a day I have plenty to go on that 20 mile ride and for longer rides we pack some GU. I find that we need to have one after every 25ish miles. YMMV

I say try it, you can definitely lose weight on a Keto diet. Be prepared, have some GU or something to get you past a bonk, as you more than likely will have one on a longer effort.

When properly keto adapted, bonking is a thing of the past (that sounded kind of wrong...) because your body runs on ketonebodies made from fat of which we all have an almost unlimited ressource. Even a very lean athlete has in excess of 100.000 calories of body fat compared to a maximum of a few thousand from glycogen in the body.

So for endurance and long distance events it works great, not so much for super high intensity where the body prefers carbs. But you can train your body to be much, much better at burning fat. Even at high output, but it takes a while.

For more info read about guys like Phil Maffetone, Stu Mittleman and Tim Noakes. They all talk mostly bout running but the physiology on the cellular level is the same. BTW Maffetone trained Mark Allan when he won the Kona Ironman 6 times in a row, and he was NOT slow on the bike!

You might ask to have this moved to the more appropriate "Training and Nutrition" section.

Um, yeah, you have to build up to it. It is a path with some suffering. But totally worth it.

Excellent points.

My gf is keto when she isn't stress eating rice. She tried to get me to go keto; like the grizzled sailors of yore I have shirked the siren call.

Basically, when compared to a keto diet it is less energy intense for your body to process carbs into muscle fuel. This fuel is what is needed to be able to go harder than say, z2. If you are taking in fuel that is less efficient to turn into the stuff your muscles use, you are giving yourself less to work with anaerobically.

My guess is that keto probably works OK for ultraendurance where you're holding a steady pace forever and ever, but is absolute garbage for anything resembling normal road racing or fast-paced group riding. While I am occasionally given back to back (to back!) bonk rides where I also avoid carbs, doing that on the regular is probably a recipe for training disaster.

Not sure how. More seems to depend on whether or not you want to tool around at a pedestrian pace or actually train to get fast.

If you want to lose weight, you just get hungry. Consequently that's also something that doesn't mix very well with training to get fast because your body needs carbs. Time and a place to cut calories for performance sake. Not so much for keto.

While I don't particularly think strict keto has a place if your goal is to race and spend lots of time above your anearobic threshold right now, to say keto doesn't have a place in getting fast unequivocally is quite ignorant of the science. You'll never be that fast if you are fat, and usually losing weight for the average cyclist is going to be the easiest way to get faster. At best, you can maybe make a 10% jump in ftp in a season? Whereas a 10kg drop in weight will increase your w/kg by that same 10% at the same power

So, my experience is that losing weight necessitates allowing your training to become somewhat inconsistent. So let's say you can normally manage 4 days of hard workouts a week, when dieting you may only get 1 or 2 good workouts in weekly. As your time in zone decreases, in order to maintain as much of your power as possible you have to make those days really count. Running a calorie deficit is hard enough; running a calorie deficit while restricting carbs seems like a bad idea if you're going to try to maintain ftp. You'll more than likely lose weight, but I'm pretty positive you'll also lose a lot of power.

I am on a low carb diet, not keto. I do it because it is best for my health, not for gains in cycling. (although I am doing fine there too)

I don't see the low carb/keto as ideal for someone who's body normal tolerates high carb diet. If you can suck down carbs and not have health issues, that is what you should be doing.

Routinely do long rides, not a fast rider, but faster than 15mph on a Metric.

I do better on day on/day off schedule, try to do one long hard ride weekends, with a medium effort and a recovery ride during the week. I try to replace 50% of calories after a ride with low glycemic index foods, lots of protein, good amounts of Omega rich fats.

You do have to be more careful not to overtrain, make sure you get extra rest so that your body repairs yourself.

Honestly, riding is not really a good choice for weightloss, not that the OP was saying they were doing it for weight loss but it is implied, it is better for overall cardio and fitness.

I've done the metric centuries in Keto. Make sure your in Ketosis for long rides. You can either eat very little or continually. I rode 75 miles with a 17.6 mph average. I ate 2 kind bars, 1 quest bar, and some almonds.

You kind of went on a nonsequitor, there, and got a bit irrelevant. You can lose weight quite readily without resorting to keto.

For weight loss:
2 days a week.
1 cup of black coffee before 45 minutes to 1 hour of Zone 1-2
then a light breakfast of milk.


For training, you won't be able to get the muscle stimulation you need for long enough to make for effective training.

Yes, it is pretty simple to lose weight if you can maintain more calories out than in. It is pretty difficult to maintain muscle mass while on a calorie deficit diet though. It is even harder to add muscle mass while in calorie deficit mode. Dropping carbs from your diet and burning fat in their place MAY allow you to increase muscle mass while shedding fat. I am not convinced of this but I have seen some pretty impressive people who are on a ketogenic diet.

I don't think this sort of thing is hard to achieve for any fit cyclist that does a reasonable amount of training.
I am not into Keto diets etc but have no problem riding a metric century on just water. I wouldn't be able to push hard for long but if the pace is kept moderate it isn't a problem.

Why would you want to increase muscle mass for cycling?

Muscle is heavy.

That's kind of a big issue.

That's why I don't get why anyone would even think of trying this to get faster, or would try to ride 60+ miles on "just water". Averaging ~276 watts an hour is ~1,000 kJ, and that's not even a lot of watts relatively speaking. You need some carbs if you want to actually ride fast.

Two years ago, LeBron James famously lost 25 pounds and upped his late-game endurance by cutting carbs and sugars from his diet.

From: The truth behind the world's most cutting-edge, fat-burning performance meal plan: the keto diet

I am not advocating it as a way to fuel your training rides but just pointing out that anyone who racks up a fair amount of training could do this if they wanted too. You don't need to of been been on a Keto diet/training regime.