For today’s edition of Dear Mark, I’m answering a question about taking ketones for overtraining from a reader.
I just saw this article  the other day and I’m wondering what you think of it. Should high-carb athletes (or regular carb athletes) be taking ketone supplements? Is there any reason why they shouldn’t? It’d be awesome to get the “best of both worlds,” but is it safe?
I saw that one too. Very interesting. Here’s the full study  they reference.
Okay, so what’s this all about?
Most ketone ester studies have looked at the benefits to performance. An athlete takes ketones prior to training, then they measure the effect it has on subsequent performance. It’s useful in that situation, improving performance by a few percentage points. I’ve noticed the same thing. Whenever I use ketones—which is rarely—I’ve usually taken them before an Ultimate Frisbee session.
Other studies have looked at post-training ketone supplementation, but only acutely. They’d have trainees work out or compete and then take ketones, with the effects including increased protein synthesis and glycogen repletion. Good to know, but what about long-term post-training supplementation? Would those acute effects translate to long-term effects?
This recent study aimed to find out. Instead of having the athletes take the ketones before or during training, or after but only in the short-term, they had them take them post-training consistently over a period of several weeks to see if they’d aid in recovery. They did.
All the athletes in the study trained twice a day. In the morning, they did either HIIT—high intensity interval training, 30 second all out cycle sprints with 4.5 minutes rest—or IMT—intermittent endurance training, 5 × 6 min with 8 min recovery or 5 × 8 min with 6 min recovery. Evenings, they did steady state endurance training. This was a heavy schedule designed to promote overtraining. There was a lot to recover from.
Both groups showed evidence of overtraining:
- Lower adrenaline at night. Increased adrenaline at night is a hallmark of overtraining and can make it really hard to get a good night’s sleep.
- Blunted decrease in resting heart rate. Acutely, stress increases heart rate. But over the course of several weeks of overtraining, an athlete’s resting heart rate will drop. Taking ketones led to a lower reduction in resting heart rate, indicative of lower stress.
- Improved bone mineral density. Ketone-takers had slightly higher bone mineral density than the control group, in whom bone mineral density decreased. This is a marker of positive response to training. In overtraining, bone mineral density tends to drop.
- Increased tolerance of training. Those who took ketone esters had a higher subjective tolerance for training on subsequent days, indicative of improved recovery.
The group who drank ketones had better numbers, though.
And when they tested both groups with a two-hour endurance session at the end of each week, the ketone-takers had better performance: more power output during the last 30 minutes.
In the past, I’ve expressed skepticism over high-carb eaters adding exogenous ketones to their diets. It just seemed physiologically “wrong” and unnatural to mix ketones and high-carb intakes, since the normal prerequisite for ketosis was a low-carbohydrate intake.
But this study, and some other research I’ve since explored, makes me wonder if adding ketones to a high-carb training schedule might make physiological sense. There are instances where exercise alone is sufficient to get someone into ketosis. For instance, in multistage ultra-marathoners —men and women running 240 km/150 miles over five days, no amount of dietary carbohydrate was able to keep them out of ketosis. They ate over 300 grams a day and they were still deep into ketosis. They even tried eating over 600 grams a day, and they still couldn’t keep themselves out of ketosis. That tells me that ketone production during protracted training is a feature, not a flaw, of human physiology. The two can naturally co-exist even in the presence of carbs.
The key is “glycogen stripping.” As far back as the 1980s, researchers knew  that depleting glycogen stores was a prerequisite for ketosis. Now, back then, most researchers saw ketosis as a negative side effect of glycogen depletion, as something to be avoided and mitigated with “proper” carbohydrate intake. They were unaware of the potential benefits ketone bodies can deliver to athletes.
Ketones are anti-inflammatory. I even know a few high-level athletes who are experimenting with extended fasting during de-load periods to reduce the effects of overtraining and speed up healthy recovery. I make the distinction between healthy and unhealthy recovery. Healthy recovery is true recovery; it speeds up the process without inhibiting healing or training adaptations. Unhealthy recovery can get you back out there quicker but you might miss out on some of the benefits of training. One example of this is using ice baths to recover from intense performances. Doing so will blunt pain and help you get training/competing, but it may inhibit some of the benefits of training, like hypertrophy. Useful when you have to get back out there (it’s the playoffs). Not so useful if you’re trying to adapt to the training (it’s the off-season).
Ketones are protein-sparing. When ketones are present in the body, you are less likely to break down muscle tissue and organs for amino acids to convert into glucose. This makes perfect sense, doesn’t it? As an alternative source of fuel for the vast majority of your body’s tissues, ketones reduce the amount of protein you need to break down to provide glucose.
Thus, contrary to my earlier assessment, what was unnatural about the study wasn’t the combination of ketones and carbohydrates. That can clearly occur in natural settings where glycogen is depleted and elevated levels of physical activity are maintained. The unnatural aspect of this study was the insane level of training these subjects were doing.
Humans are built for high volumes of low-intensity work and movement—walking, hiking, gathering, low-level labor.
Humans are built for low volumes of high-intensity work and movement—fighting, killing and field dressing large mammals, carrying heavy objects.
Humans are not built for high volumes of high-intensity work and movement—”two a days,” sprinting in the morning and going for long bike rides in the afternoon. We can do it, but there are consequences.
So what the ketone esters are doing is restoring the natural balance. They are physiological tricks to restore order in a highly-stressed body asked to perform supranatural feats of endurance.
If you try them out for this reason, I have a few suggestions:
- Don’t use ketones as a way to get back out there and keep overtraining. Instead, use them to enhance the training effect—to improve your recovery, to make your time off more meaningful and effective.
- Consider simply going keto. Adding ketones to a bad diet might be better than nothing at all, but the real benefits come when you commit to going keto, build up those fat-burning mitochondria, and become truly fat-adapted.
Taking ketones after a training session clearly works. But you can get there just as easily, with likely downstream benefits, by going low-carb. I’m reminded of the study from a few years ago where athletes “slept low “: after similarly grueling training, they’d eat a low-carb meal (rather than refuel their glycogen) and go to sleep.
They rapidly reached the very-low carb /ketogenic state for a good portion of the day by depleting glycogen and failing to replace it, from the afternoon snack to the post-workout breakfast. They weren’t just “high-carb.” They were smart carb, filling the glycogen , depleting it, and forcing their bodies to run on fat for a while.
To me, that’s a better (cheaper, too—ketone esters are expensive!) way to get similar results.
But whatever route you take, it’s a good way to spend time in the ketogenic state. The presence of ketones, especially paired with training, is a good thing for anyone.
What’s your experience taking ketones? How do you incorporate ketogenic states into your training schedule?
Thanks for reading, everyone. Take care!