Exercising While Fasting


(Cesare) #1

I was wondering if anyone had experience with heavy exercising while fasting. I wanted to know what to expect or feel while continuing to strength train and cycle while doing an extended fast.

Thanks guys!


(Guardian of the bacon) #2

@richard does like 60-100km bike rides often just before breaking an extended fast.


(Tim) #3

I was wondering the same thing about strength training during an extended fast. Where does the protein come from that’s needed for muscle recovery and rebuilding? I understand that HGH levels rise while fasting to assist with the rebuilding process but is this enough in the absence of added protein?

I was thinking of fasting this week and want to make sure resistance training midway through won’t cause any problems.

Thanks!


(Erin Macfarland ) #4

It depends on how much body fat you have. The leaner you are the harder it is to fast for extended periods while working out.


(Bart) #5

I have ran 8-10 miles regularly after faster for 24 hours and have always felt great. I do make sure I have some bullion and magnesium earlier in the day before the run, I have cramped bad when I have not supplemented minerals. I have done this with body fat percentages as low as 8-9%. I will say this though, you can smell the ketones in my sweat, not the most pleasant thing. *** Note, this is me and my body, not making any recommendations. ***


(Cesare) #6

Well i starter a 5 day fast today so i will report back with my findings!


(Christina Hansen) #7

Your body can get the amino acids it needs to rebuild muscle from autophagy. Remember, fasting is muscle-sparing. The protein breakdown that comes from fasting/autophagy is coming from old cells and damaged proteins that need to be removed anyway.


(Jo Lo) #8

Since going LCHF/Keto two years ago I’ve done all my 2xwk Crossfit WODs fasted, and dozens of long runs (up to 26.2 mi) and 5 days of backpacking on the PCT with minimal food while exercising. Once you get fat adapted you can do this without hunger, and at moderate intensity. It may not work so well at high intensity… but I monitor my heart rate and try to keep it around 70% for endurance work. This is Primal behavior IMO. Our ancestors did a lot of low to moderate intensity moving, only rarely going all out. Read Primal Endurance.

I think Ted Naiman said in a tweet that there are only three times you need to feed carbs: before, during, or after exercise. That way it is used immediately and not stored. Otherwise, limit carbs, push protein, and scale fat (more if you are lean, less if you want to lose).


(Vivian) #9

And hopefully autophagy of loose skin!


(Blyss (Old @Charmaine)) #10

This was a response I gave to a similar inquiry on FB in another group. Rather than typing it over, I’m pasting it.

"On January 8th, I ended a modified extended fast of 21 days. I say modified because if I had done a water fast, I wouldn’t have been able to work out; I included fats, bone broth, and some protein as needed. During week 1 I had bone broth, but didn’t include it in weeks 2&3 - that was a personal choice. At the end of week 1, I actually bested my previous leg press PR by 10lbs. What happened was, I got hyped. LOL The adrenaline and ketones were flowing for both of the chosen lifting days and next thing I know, I was doing more than I should have. I payed for the lifting the next few days (funny but not funny).

I maintained my workouts, they were just less intense for the most part, over the last 2 weeks. I was surprised that I had no issues outside the recovery from the new PR. My body couldn’t reasonably keep up with the needs created by the workout.

This was totally my own n=1 that I was determined to see what would happen. I monitored bp and bg; I kept up with electrolytes and kept muscle cramps at bay; again if I needed to have some fat/protein I’d have a small amount. I don’t know how autophagy was affected, but I lost a total of 15lbs and never had energy or hunger issues."


(Blyss (Old @Charmaine)) #11

And another response to further inquiry about recovery.

"… the only recovery I had difficulty with was after the first leg day where I set a new PR on the leg press. It wasn’t my original intention to go heavy any at all, but like I said I got all hyped and next thing happening was me press 578lbs x 10. I learned not to go all out with the strength training on fasts. A shorter extended fast is different (which I have done). But the week before I started the 21 days, I inadvertently prepared for it by doing a sort of fat fast (I had initially planned to start the 21 days on January 1, but said what the heck why wait?) with one mini meal a day of probably 90% fat. There were no issues with fatigue, recovery, or strength for any of the other workouts.

With this experience, I better know the parameters for me to stick to when I do a long fast again. Keep the workouts moderate. Endurance isn’t an issue at all; no full out HIIT training."


(Jason Fletcher) #12

Thought this may help here was the link his comments


(Larry Ozenberger) #13

I’m currently in my third seven day water fast. I’ve had good results starting these extended fasts with a hard workout on the first day.

My hard workouts are 90-minute hot yoga classes. Doing this on the first day seems to knock the glycogen levels down and speeds my transition into deeper levels of ketosis. It also helps with hunger, as I often do IF on yoga days anyway.

I have been doing three yoga classes during the extended fasts and two lighter Aikido workouts on other days, which is my regular schedule. Later in the fast, the effort expended in the workouts is moderated if I’m feeling light-headed or unwell.

I make sure to get enough water, electrolytes, and sea salt. I continue taking my vitamins and other supplements, and do a little bone broth on the first two days. On this plan, I lose some lean mass but it bounces right back after the fast ends. The post-fast workouts are fantastic, I guess because of elevated HGH and improved mental focus. My plan is to keep doing this about once a month as long as it seems beneficial.


(Tim W) #14

I’ve done five day fasts where I ran 3 days and did a full body circuit workout (mod weight, 10 reps, 5 sets) 2 days and no issues.

I’ve fasted for six days, running 3 days during the week and 12 miles on the sixth morning, no issues.

I started out IF over a year ago and often worked out in the morning after having my last meal at 1800 the previous evening (so working out about 8 hours after eating) and then didn’t eat again until 12 hours later, no issues.

I think it’s an adaptation issue. Playing with a protocol long enough allows us to adjust to it and really push the boundaries of what’s “normal”.


(Peter Barney) #15

I find now, 2 years into keto and fasting, that my blood ketones don’t skyrocket when fasting and urine test barely register.

Using moderate workouts and steady long runs to drop out glycogen levels stops my body sitting in cruise control. It sets me up for a strong workout and effective refeed, normal very good lean muscle gains and pace improvements shortly after fast.