Power output has gone way down


(What The Fast?!) #1

Hi Cyclists.

I have been keto for almost a year now and more recently, I’ve incorporated a lot of extended fasting. I noticed since I started doing more fasting that my power output is going way down. I’ve tried riding both fueled up (eggs/bacon pre-ride) and fasted (18 hours). In both cases, both my power output and speed are much lower than before I started doing extended fasting. I know that fasting is supposed to be muscle sparing, but I’m wondering if I’m doing more harm than good when it comes to athletic performance.

For those of you who don’t know me, I started doing extended fasting because I wasn’t losing any weight with keto. Weirdly, I’m about 5-6lbs lighter now…so I’d expect to be faster, but I’m much much slower and my power output went from 115-130 to 90-99.

Energy wise, I’m on fine while riding, I’m just sloooow and apparently, not powerful. My heart rate is definitely trending higher since going keto (and maybe even a little higher since all the fasting). I will chart out my trends in HR, power, and speed over the weekend to see if I can find some patterns…but right now, it just seems like I’m losing fitness.

As a side bar, I’ve also noticed that my strength in the gym is lessening as well.

(ianrobo) #2

Hi !

OK as you know when you fat adapt at the start you will lose power but I personally found after 2 months or so I was back where I was.

You sound like you are fully fat adapted so thats not the problem but HR higher is something I asked Steve Phinney about and the answer was MORE salt, have you tried that ?

So with the low of power I wonder what type of rides you are doing, if fat adapted IMHO you would be be doing longer and slower - MAF method and if you put in too many HIIT sessions I believe that will not help.

And of course I ask what is the ultimate goal for you ?

(What The Fast?!) #3

Thanks for this. I will try more salt for sure. I’m also getting a DEXA today to see if I’ve lost muscle.

I do the same rides I always have - we live near Red Rock in Las Vegas, so my typical weekday ride is 15 Miles with about 850 climbing. Weekend rides are around 32 Miles with 1500 feet climbing. (We do longer as well, but that’s normal.) It’s cold now so my HR should be way lower than in the summer, but it’s not. I spent the cold months doing studio classes of a TRX/kettlebell mix, a form of HiiT, but not traditional 15 min max HiiT. I haven’t been riding as much as the summer but if I look at my past rides from early season, my power is still much higher and speed is faster.

My goals are: weight loss (both for aesthetics and to improve my time on the bike), improved power and speed…mainly so I can keep up with the people I ride with. I also want to beat my last Century time…that was pre-keto and I’m wayyyyy slower now than pre-keto…but I would LOVE to do that Century again and not have to eat all those Clif bars…

(ianrobo) #4

oh you will, thats for sure, I can do a century fasted with no issues … just keep riding more and more fasted and ensure you get those salts in …

(What The Fast?!) #5

Will report back after the DEXA. I showed muscle loss from my first to my second, hoping it hasn’t dropped further.

(ianrobo) #6

I would be surprised, but how much Protein are you eating ?

(What The Fast?!) #7

Moderate amount. I used to track meticulously but had to stop because my stress was through the roof. I have about 98-99lbs of LBM, so my protein target was 45-65, I was generally on the higher end of that. Now that I’m fasting so much, I don’t track anything aside from ketones (which are high with low BG).

I don’t feel great fasting and both Richard and I think my body is having a hard time accessing fat for energy (albeit a low fasting insulin level) for some reason. It’s a weird perplexing situation I’ve been trying to figure out for 6 months. If that’s the case, it might make sense if I’m losing muscle.

I’m going to start testing out adding additional carbs right before a ride during my feast days.

TBH, while I love keto, im at the point where I need to evaluate if my body does or not. The only way I’ve lost weight is aggressive fasting so I think I may look at Paleo/whole foods mixed with extended and intermittent fasting to see if I get better results. I’m not there yet, but I’m close. …let’s see what DEXA says.

PS thank you for your thoughts. You have had incredible cycling results and was hoping you’d chime in! Just had a 1/2 tsp of salt!

(Alan Williamson) #8

It takes some time to adapt to using fat for fuel. The cells need to grow more mitochondria to burn fat efficiently. For example a cell might have 10 mitochondria. For fat burning, it might have 20 or 30 mitochondria. This doesn’t happen overnight, and the cells need to be stressed to adapt. For fat burning, insulin level needs to be low, and glycogen needs to be depleted. This happens on day 2 or day 3 of a fast. I have lifted the most weight ever for myself on day 5 of a fast. HGH was high, and my adrenalin was jacked. It was awesome.

(ianrobo) #9

No probs and I would say if exercising you need more protein anyway than a sedentary person so the calculation you hear about is upped. I do monitor and keep protein to around 25% over a week time but that goes up and down.

(ianrobo) #10

which is why in cycling fasted cycling is so good for this for the same reasons and as long as you are careful with efforts you will never run our of glycogen

(What The Fast?!) #11

I’ve been keto (and training) for almost a year though. I think there’s something whackadoodle going on in my system. Currently getting a bunch of tests done to see what’s up.

(What The Fast?!) #12

Had a DEXA today. Lost 4 lbs of lean mass in the last 8 months, 3 of those in the last 6 (since I started doing a lot of extended fasting). I’m perplexed by the results but seems to go along with my power output trends. Feeling discouraged but headed out for a couple hour ride today.

(ianrobo) #13

maybe but how much fat mass did you lose ?

(What The Fast?!) #14

2lbs. In 8 months. My BF % is still about 30%.

(ianrobo) #15

hmm can not think why this would be the case, does not ring true does it ?

(What The Fast?!) #16

Sorry, not sure what you mean. What doesn’t ring true?

(ianrobo) #17

why you are losing lean and not fat mass when Keto and exercising, I can not even try and think why ? it is like your body is craving protein yet you say you take enough ?

(What The Fast?!) #18

This is what I’ve been trying to figure out…I can’t comprehend why it’s simply not working like it’s supposed to…ESPECIALLY considering that I don’t have IR and have very low fasting insulin. I like your interpretation though - I’ll try and add protein and see if that helps.

(ianrobo) #19

maybe @richard could put a couple of thoughts on this ? he is the protein expert !!

(Boston_guy) #20

Are you taking Creatine/Glycine? https://chrismasterjohnphd.com/2017/12/21/creatine-far-more-than-a-performance-enhancer/

20:28 Creatine increases muscular contractile power by reducing ionic strength.

22:28 Creatine acts as a pH buffer.

25:36 Creatine is constantly recycling ATP, even at rest, but during intense exercise, creatine is used up faster than it can be recycled.

28:23 The creatine kinase system is especially important in cells and tissues that have 1) fluctuating energy demands, 2) high energy demands, or 3) long, polarized structures.

You take glycine and arginine, and you make guanidinoacetate, and then you methylate that to produce creatine. So if you don’t have enough glycine or you don’t have enough arginine or you don’t have enough methylation capacity, your creatine synthesis can suffer.