Hi! I am on day 8 of what I hope to be a 35 day water fast. I was wondering if as long as I take in the proper electrolytes throughout the day, it would be okay if I went to the gym and did cardio. I was hoping to do this to accelerate weight loss. This wouldn’t cause any damages right? If my body is in state of ketosis and using fat for energy, then further energy usage through exercise would just burn more fat. Also would exercising mean I should increase my electrolyte intake? Thanks
Yes, you can exercise while fasting.
You lose electrolytes whenever you lose fluids, for the most part. This includes sweating so it would be wise to take in extra electrolytes when you work out.
Most importantly just listen to your body. If you start feeling off in any way just take a break, get your electrolyes and don’t push it. The extra couple hundred calories burned is not worth passing out on the treadmill.
Definitely take in your electrolytes. You might have to adjust how much you take as you work out, especially on a longer fast and especially deeper into the fast. Most people just focus on salt because of how much is lost in your sweat (and you definitely want to make sure that you up your salt), but a lot of people sleep on Magnesium, Calcium, Potassium, and Chloride while working out, all of which can pull out of your sweat as well. Magnesium actually helps trigger your muscles to contract and as you go longer into your fast, you could have spasms if you don’t make sure to take your magnesium.
All that being said, making sure you take your regular electrolytes and then rehydrating after your work out with an electrolyte mix should be fine. Taking a magnesium at night should also be fine. If you start getting muscle cramps or feel like there’s a skip in your heartbeat, up your potassium to a safe level and stop the workout. Try again the next day. A multivitamin will help replenish your thiamine and calcium on a longer fast and while not necessary on shorter fasts, will definitely help with the longer ones for some of those hard to supplement things we all need.
Just take it slow. If you worked out before your fast, your strength isn’t going to be where it was prior, but you might be surprised at how well your body steadies and maintains function. Listen to your body. Since it sounds like you’re doing cardio, try to do things less impact (biking/swimming) and again listen to your body.
All in all, working out during your fast is actually advised to keep those muscles moving! Just keep it safe and keep hydrated with water and electrolytes, definitely!
Personally I don’t know how anyone exercises during prolonged fasting. I did a 5x day once, walking three times per day just one mile at a time and I was spent, got cramps and wicked muscle tightness. I wasn’t taking electrolytes. But even still, just seems far too risky to me.
Edit: perhaps it matters how much extra body fat you have as well. I had near none.