Low Energy 2 Hours into Ride

(Manuel Wanskasmith) #1


I have been on the keto diet since Dec. 14 2018 and am having difficulties on longer rides.
I’ve been an adventurous cyclist for many years and am currently training for a 200 mile ride in Kansas on June 1st 2019. The reason I started keto was to gain better endurance for long rides and get off of the high-carb spike/crash cycle.

My issue is that I start rides with good energy and strength, but right around the 2 - 2.5 hour mark I start feeling foggy-headed and have difficulty maintaining a pace that I would normally maintain just fine pre-Keto. The more strenuous I ride, the sooner I reach the plateau. It’s NOT bonking – I would call it a pre-bonk.

I have noticed that my heart rate is higher than most cyclists given the same amount of effort. On rides where my friends are in Zone 2 or Low 3, I am spending a lot of time in high zone 3 and Zone 4. This has always been the case, and did not change after I entered ketosis.

I wonder if I am even sufficiently fat-adapted. I try to limit my carbs to 30g or less per day, but realistically I’m probably in the 30-50g range daily. I do experience the other benefits of Keto – can fast for several hours without crashing, I’ve lost about 5% of my body weight and kept it off, am generally eating healthier and more nutritious foods.

Pre-ride, I will have a teaspoon+ of Lyte Show electrolytes mixed in water. If it’s going to be more than a few-hour ride, I’ve been eating 30g of Generation UCAN Super Starch, a slow-release carb source, to keep the glycogen stores topped off. It does not make a difference with the 2 - 2.5 hour issue.

During rides I try to snack every hour or so, with nuts, sausage, mashed avocado, fat bombs, various keto-friendly snacks. Sometimes a Generation UCAN bar. Sometimes a Bulletproof Collagen bar. I hydrate with a zero-sugar, zero-carb mix that provides some electrolytes.

I don’t measure my ketones in any way. I used the urine strips in the first 30 days, but of course their effectiveness drops off. I have a Keyto on order, but it won’t ship until late April.

I am pretty close to pulling the plug on the keto experiment, because I need to train a lot over the next 7 weeks. Does anyone have any comments or suggestions of things to try? Ask me anything you want clarified. Thanks in advance.

(Joseph) #2

Same boat. Started on the first week of December with LCHF & TRE (16:8, 18:6, and occasional OMAD), and a few IF (just slightly over 24+) for weight loss and metabolic repairs. My double is on 5/18 (first ever but done a number of centuries and a couple of 200k). What I’m reading is that it takes a long time to be fully fat adapted, 6 months to 2 years. Prior to the diet change, 2-3 hours at tempo is typically what I can do without eating.

Thus far I’m averaging 80-100g of carbs a day per week and more equal protein and fat than high fat. Initially, I was able to incorporate one or two fasted workouts per week (~1-1.5 hour rides at low tempo, IF of ~0.78+) but stop doing it mid-February when I ramp up duration from 6 to 10+ hours a week (indoor sweet spot base plan). The fasted rides was just too draining. Just tested my limit in the last two weeks. 3/15 was a 6.5 outdoor ride with IF of 0.797 and had only one UCAN bar before ride start and didn’t eat until after 2-hour mark (four bars total). Last Saturday and Sunday, I road 4.5 and 1.5 hours indoor (initially fasted) with IF of 0.7 and 0.79 respectively. I had to eat around the 2-hour mark on Saturday (three bars total) and my power dropped off significantly after 1.5 hours in (IF of 0.73 & 0.69 remaining three, planned for a 6-hour track but had abandon). Sunday was supposed to be an active recovery but felt ok after warmup so tested to see if I can make up for lost time. Nope. The two weeks prior, a 4-hour trainer ride with IF 0.78 on 3/2 and 5-hour and IF of 0.762 on 3/9, was with light breakfast and eating after ~2-hours on the bike.

I think the fasted rides that was giving me problems initially was because my fitness was at an all-time low. My CTL was at 16.4 after being off three months recovering from being rear-ended (minivan vs bike). It’s now in the mid-60s. I’m going to resume once a week fasted rides to see how it goes (mainly for weight loss). Figure I got plenty of time to experience since the big day is seven weeks away and had fairly good results so far. I was in a similar boat the year before, shoulder surgery with three months of recovery and trained for six months after for the Death Ride (finished but it hurt). I had a hard time regaining fitness and couldn’t drop the weight gained as part of the recovery. This time it has been easier and seems to be on a faster trajectory.

(Manuel Wanskasmith) #3

Thanks jkc, good to know I’m not the only one struggling. So many acronyms in your post I don’t know… TRE? CTL? IF of 0.78?

Yeah, I’m transitioning off keto. I just don’t have the patience to suffer 6-24 months to find out if I can get fat adapted enough to support the kind of riding I do. I created a problem for myself by going on this diet, and since the solution seems to be to add carbs back in, that raises the question of why the heck am I doing this at all? I’ll go back to carb-fueled, but try to pay more attention to the quality and type I consume. Have learned a ton about sugars. UCAN Superstarch seems to give me good long term energy without the spikes and crashes.

Now I wonder if there’s a sub-forum here about tips for transitioning OFF keto…

(Joseph) #4

Sorry about the acronyms.

(traci simpson) #5

Wouldn’t you feel that regardless of what diet you are on? that’s a long ride and a lot of burned energy (fuel). I know my rides which are finished at hour 2, I feel like I’m just gonna drop dead. I usually just eat two boiled eggs and that’s it. I did a 40 mile race in NY and we had bagels, power bars, bananas, and such but that was to help with the sugar which will help you finish the race. I work with the an association that puts on Marathons and the food that they give ranges from orange slices, to jelly belly’s, vodka, bananas, electrolyte power, or bars etc. to give you that quick sugar rush you need at say mile marker 10 or 15. Maybe on the days you ride that distance, indulge in some carbs or sugars that you wouldn’t ordinarily eat.

(Joseph) #6

Depends on the intensity. Just finished a 121 miles ride with 7,377 feet elevation gain and 8:47 moving/9:59 total. Overall ride intensity was 0.747 or upper endurance pace. I had one scoop of UCAN before ride start, 5 UCAN bars during, and half a ham & cheese sandwich for lunch. Dinner was after a 1.5 hours drive home. Ride expended 4,384 kJ or roughly 4,415 kCal and ate ~1,270 kCal. Minus ~2,000 kCal glycogen reserve, I was in the hole of ~1,145 kCal. The “bonk” would have hit me around hour 6. My ride was not a fast ride due to cramping after hour 5 (never developed into full cramping just that tingling feeling you get before the muscle locks up) but I never felt dead (although the last climb starting 6:20 was not fun, 1,014 feet elevation gain over 3.2 miles with average gradient of 5.9).

(traci simpson) #7



Give this a listen. Ian went through periods where extra salt helped and fasted training enhanced fat adaptation.


Instead of quitting keto try a targeted approach. I suffered the same as others but I started taking dextrose (Karo Syrup) half hour before I rode. Two tablespoons is 30 grams of carbs. It goes straight to the bloodstream and is burned right away. Never effected my ketone levels.

(JJ) #10

Yes, I know this is an oldie, but it is pertinent to a question I came on here today to specifically research.

So many people state they do great fasted and feel better and can go all day on a bit of salt- I am not one of them and it sounds like a few others may also feel similarly about their own performance? I am very interested in the idea of TKD and that theoretically someone who is fat adapted and of a healthy body weight could maintain ketosis even with a strategically consumed bit of carb action.

I ‘only’ cycle about 80-100km a week ( I know that is nothing for you serious cyclists) and can do a ride of 1-1.5hours okayish fasted, but it feels way better if I at least have a fatty coffee before, if not an actual little meal. My running efforts are the same, short runs okay. Anything above 7km- half marathon distance I need fuel or I feel crappitty big time.

Yesterday, I did a 3.5 hour ride. I ate a chaffle before hand and then at the halfway mark stopped for a coffee, ate a homemade keto muesli bar and 1x medjool date. I rocketted home, I felt awesome. So I think that perhaps there may be something in a TKD for me. I felt amazing, strong and struggled far less than I have on much shorter rides. The medjool date was eaten on a whim, but I do have some UCan that I use if running a half, haven’t used it for cycling yet though.The date consumption and sensation of having consumed rocket fuel is what got me wanting to learn a bit more about the idea.

I have been keto since Dec 18 and been in maintenance mode since mid last year after losing 50 pounds pretty quickly. Although I am appreciating the continual improvements to body comp and my overall fitness, I would not want to be any ‘smaller’ than I am now. My husband has also expressed concern about me shrinking any further, so I am aiming to hold steady, enjoy my running, hiking, weight training and cycling.

Does anyone regularly utilise TKD into their activities? How is it working? Do you feel you slip back into ketosis well afterwards? Or is CKD and then fueling with low carb options working better for you?