Exercise-induced Ketosis?
Robertus
Posts: 558 Member
Hi. I learned a very little bit about ketosis many years ago but have never tried to follow a long-term ketogenic diet. I have, however, done some fasting and long-distance swimming in my weight loss journey and I am wondering if 'exercise-induced ketosis' is a thing?
I do not have a target weight, at least not yet, anyway, and weight loss is not my primary goal, but it is, of course, desirable and a secondary goal to my primary fitness goals.
I was struck by this passage from Marcia Cleveland's book, Dover Solo: Swimming The English Channel. She doesn't have medical or physiological training, but practical experience in swimming very long distances.
I have also done this, I think with some success. It is certainly not a way to cheat the basic mathematics of CICO, but I'm thinking it may be a way to get your body into ketosis more aggressively than merely fasting. It seems to be essentially what what many marathon runners describe as 'hitting the wall' around the 23-mile mark. Since I too have no medical or physiological expertise, I do not recommend it too others, but I do it myself sometimes, about once or twice a week on long swims of 3 miles after not eating that morning, or sometimes not even the day before, at least not much. A couple of times, it was a little scary afterward (ie, feeling like I might faint, dry heaves, tingling in my fingers), and I needed to sit still for quite a while before I started to feel normal again. Later on I always follow up with a big dose of protein (steak or lobster) for the rest, restoration, and rebuilding phase. I now sometimes also eat a protein bar before I do this, at the recommendation of a pharmacist friend.
A couple of articles I saw today also seem to indicate that longer-term moderate intensity aerobic exercise may burn calories more effectively than higher levels. Obviously, moderate levels of aerobic intensity can be sustained for a much greater length of time. I call this swimming in an aerobic loop, where it feels like you can almost effortlessly increase distance just by increasing the time of the work-out. Here are the articles I'm referring to:
Anne Bach Stisen, Ole Stougaard, Josef Langfort, Jørn Wulff Helge, Kent Sahlin, Klavs Madsen. Maximal fat oxidation rates in endurance trained and untrained women. European Journal of Applied Physiology. November 2006, Volume 98, Issue 5, pp 497-506
Stefano Lazzer, Carlo Busti, Fiorenza Agosti, Alessandra De Col, Renzo Pozzo, Alessandro Sartorio. Optimizing fat oxidation through exercise in severely obese Caucasian adolescents. Clinical Endocrinology. Volume 67, Issue 4 October 2007 Pages 582–588
By the way, the reason I have not tried to follow a sustained ketogenic diet is that increasing fitness and endurance is a more important goal for me than weight loss. And this seems to be aided by eating back a lot of exercise calories (not all) after long work-outs when my body is in rest and rebuilding phase. Maybe this can also be done by eating mostly protein and fat during this phase, but I tend to just eat what I like! Nonetheless, I have lost 60 lbs in the first 3 months of my 'dieting' phase, which I started doing after first starting to work on basic fitness for about a month.
Thoughts? Resources?
PS: Please feel free to add me as a friend. You can never have too many good friends!
I do not have a target weight, at least not yet, anyway, and weight loss is not my primary goal, but it is, of course, desirable and a secondary goal to my primary fitness goals.
I was struck by this passage from Marcia Cleveland's book, Dover Solo: Swimming The English Channel. She doesn't have medical or physiological training, but practical experience in swimming very long distances.
[Mike Oram, pilot of an escort boat for channel swimmers] suggested that I go into my long pool swims on an empty stomach so my body would learn how to burn fat effectively. Since I did not eat before my morning workouts I was already doing this, thus simulating the physiological condition after swimming for a few hours. My system was already learning to switch over from its initial stores of carbohydrates and glycogen to fats right from the start of a swim."
I have also done this, I think with some success. It is certainly not a way to cheat the basic mathematics of CICO, but I'm thinking it may be a way to get your body into ketosis more aggressively than merely fasting. It seems to be essentially what what many marathon runners describe as 'hitting the wall' around the 23-mile mark. Since I too have no medical or physiological expertise, I do not recommend it too others, but I do it myself sometimes, about once or twice a week on long swims of 3 miles after not eating that morning, or sometimes not even the day before, at least not much. A couple of times, it was a little scary afterward (ie, feeling like I might faint, dry heaves, tingling in my fingers), and I needed to sit still for quite a while before I started to feel normal again. Later on I always follow up with a big dose of protein (steak or lobster) for the rest, restoration, and rebuilding phase. I now sometimes also eat a protein bar before I do this, at the recommendation of a pharmacist friend.
A couple of articles I saw today also seem to indicate that longer-term moderate intensity aerobic exercise may burn calories more effectively than higher levels. Obviously, moderate levels of aerobic intensity can be sustained for a much greater length of time. I call this swimming in an aerobic loop, where it feels like you can almost effortlessly increase distance just by increasing the time of the work-out. Here are the articles I'm referring to:
Anne Bach Stisen, Ole Stougaard, Josef Langfort, Jørn Wulff Helge, Kent Sahlin, Klavs Madsen. Maximal fat oxidation rates in endurance trained and untrained women. European Journal of Applied Physiology. November 2006, Volume 98, Issue 5, pp 497-506
- Training-induced adaptation in muscle fat oxidative capacity.
- The highest rates of fat oxidation occur at moderate exercise intensity, ie, 56% VO2max for endurance trained athletes and 53% for untrained people.
- http://link.springer.com/article/10.1007/s00421-006-0290-x
Stefano Lazzer, Carlo Busti, Fiorenza Agosti, Alessandra De Col, Renzo Pozzo, Alessandro Sartorio. Optimizing fat oxidation through exercise in severely obese Caucasian adolescents. Clinical Endocrinology. Volume 67, Issue 4 October 2007 Pages 582–588
- Severely obese and sedentary nonobese adolescents reached maximal fat oxidation rates at 41%V̇O2max, which corresponds to 58% HRmax.
- http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2265.2007.02929.x/full
By the way, the reason I have not tried to follow a sustained ketogenic diet is that increasing fitness and endurance is a more important goal for me than weight loss. And this seems to be aided by eating back a lot of exercise calories (not all) after long work-outs when my body is in rest and rebuilding phase. Maybe this can also be done by eating mostly protein and fat during this phase, but I tend to just eat what I like! Nonetheless, I have lost 60 lbs in the first 3 months of my 'dieting' phase, which I started doing after first starting to work on basic fitness for about a month.
Thoughts? Resources?
PS: Please feel free to add me as a friend. You can never have too many good friends!
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