I’ve been experimenting with fasting for over a year now. I routinely do intermittent fasting, where I’ll skip breakfast and try to eat my meals within an 8 hour period. I’ve also done longer fasts, ranging from 2 days to 5 days. But when I’ve done the longer fasts (longer than 2 days) I’ve been nervous about doing a high intensity workout. Today I confronted that fear and I am so glad I did.
I’ve been fasting for 3 days, with nothing but coffee with cream and MCT oil in the morning and water throughout the day. Today I started drinking water with Zip Fizz because I was getting a headache from dehydration. I fast for a number of reasons – to help get rid of diseased cells, to cleanse my body when I haven’t been eating as well as I should, for weight management, and because I like how I feel when I’m fasting (most of the time).
I decided I was going to do a High Intensity Interval Training (HIIT) workout on the trainer to see how I would feel. I did 30 minutes of interval work, where I would get my heart rate as high as possible, pedal easy for 30-60 seconds, and then do it again (starting with a warm up and ending with a cool down).
I felt great. I had done a similar workout on Sunday, and today I felt better (and stronger) than I did on Sunday when I hadn’t been fasting. I’m planning to fast another full day, and will try to ride outside tomorrow (a longer ride) to see how I feel.
On prior fasts longer than 2 days, I’ve fought with dehydration headaches. This time I’ve been far more committed to my hydration than before, and it has definitely made a positive difference. One thing I did notice during today’s workout is that I did not sweat nearly as much as I did on Sunday…not surprising given the dehydration that occurs with fasting.
If you’re thinking about fasting, there are a number of great articles online, or if you’d like something more comprehensive, read The Complete Guide to Fasting by Jimmy Moore and Dr. Jason Fung.
On your longer rides, what do you fuel with.
I usually start with KetoCaNa 15 minutes before I start. They now make a strawberry lemonade flavor that is far better than what they had originally. It helps boost ketone levels prior to exercise. Just be careful as it can upset your stomach the first few times you use it, so experiment and see how you feel before going out on the bike. In my water bottles I have water in one and ZipFizz in the other.
I usually don’t eat anything unless I’m riding over 3 hours. I then use Stabilyze bars, and Atkins Trail bars (the ones with no sugar alcohols). I’m more concerned with hydration on my rides than I am with fuel, since I’m burning fat as fuel during rides. I hope this helps!
Thanks so much. I’ve just started w Keto and I’m finding on my training rides over an hour I’m finding trouble hitting my z4/z5 power zones. Thinking it’s because I have no glucose in me….