Exogenously delivered ketone supplements significantly altered rat weight gain for the duration of the study (Fig. 6). However, rats did not lose weight and maintained a healthy range for their age. Rats have been shown to effectively balance their caloric intake to prevent weight loss/gain [97–99]. Due to the caloric density of the exogenous ketone supplements (Table 1) it is possible for the rats to eat less of the standard rodent chow and therefore less carbohydrates while maintaining their caloric intake. Food intake was not measured for this study. However, if there was a significant carbohydrate restriction there would be a signifcant change in basal blood ketone and blood glucose levels. As the hallmark to the KD, carbohydrate restriction increases blood ketone levels and reduces blood glucose levels. Neither an increase in basal blood ketone levels nor a decrease in basal blood glucose levels was observed in this study (Fig. 7). Additionally, if there were an overall blood glucose decrease due to a change in food intake, this would not explain the rapid reduction (within 30 min) in blood glucose correlated with an elevation of blood ketone levels after an intragastric bolus of ketone supplement (Figs. 2, ​,33 and ​and44).

Ketogenic Diets and Physical Performance – Impaired physical performance is a common but not obligate result of a low carbohydrate diet. Lessons from traditional Inuit culture indicate that time for adaptation, optimized sodium and potassium nutriture, and constraint of protein to 15–25 % of daily energy expenditure allow unimpaired endurance performance despite nutritional ketosis.
Athletic performance benefits: The use of exogenous ketone supplements for bettering physical/athletic performance is promising for several reasons. Firstly, taking exogenous ketones (particularly BHB salts) induces acute nutritional ketosis for upwards of eight hours, mimicking fasting physiology (e.g. increases fat burning, insulin sensitivity, etc.).[3]
Although decreases in FFA, TG and glucose occurred, there were no significant differences between the KE and KS drinks or with intake amount. Ingestion of ketone drinks significantly decreased overall mean plasma FFA from 0.7 to 0.4 mM, TG from 1.1 to 0.9 mM and glucose from 5.7 to 4.8 mM after 1 h (all p < 0.05). Concentrations were the same as at baseline by 4 h, with FFA at 0.6 mM, TG at 0.9 mM and glucose 5.1 mM (Figures 2A–C). There was a rise in insulin concentrations 30 min following all drinks, probably due to the small amount of carbohydrate in the sweetener (Figure ​(Figure2D2D).
Will taking exogenous slow down my fat loss? Since now before digging into my body for energy/ketones, I will first use up the exogenous ketones I ingest. Also do exogenous ketones somehow help get even more keto adapted, keeping in mind I have been on a strict keto diet without a problem and don’t mind it at all. Outside of performance improvements, do you think exogenous ketones is for someone like me who is primarily looking for fat loss.
The second ketone ester compound was developed at the University of South Florida. This is a diester of AcAc and BDO. In rodents, this ketone ester raises blood D-BHB to 1-4 mM and blood AcAc to up to 5 mM.19 There is one published study of this ketone ester in humans; results showed a 2% decrease in 31 km cycling time trial performance.16 This may be due to the high rate of side effects of this ester studied. Other factors may have been low levels of BHB (<2 mM), the short, high-intensity time trial used, or the use of AcAc vs. BHB.
Uncontrolled diabetics may face some risks in using exogenous ketones. This is because when the body is unable to produce insulin (type I diabetics and extreme type II diabetics), it is unable to get sugar or glucose into the cells.  Therefore, the body will start producing ketones.  If these individuals do not use an insulin injection, they can overtime build up unsafe levels of ketones (6).
The best time to start a one day fast is in the evening (neither morning nor the night) – preferably, around 6 pm. It won’t make you lose your vital energy during the daytime workouts, nor does it let you sleep with undigested foodstuff in your stomach. Taking late meals and sleeping with undigested food doesn’t allow your body to rest. So the natural healing mechanism of your body fails during the sleep time as the entire resources are busy digesting your food.
However, with the ketone esters, the effects are nearly immediate, and my entire body was humming throughout the entire day, but not in a jittery way. I was full of mental and physical energy that lasted without any sort of crash (it was a gradual taper). During my cognitive tests, things felt almost effortless as I played the various games. After my experiment was complete I continued writing code for several hours, then went to the gym to work out. I did forget to each lunch though, so there must be some suppressive effect on appetite.
Elliot received his BS in Biochemistry from the University of Minnesota and has been a freelance writer specializing in nutritional and health sciences for the past 5 years. He is thoroughly passionate about exercise, nutrition, and dietary supplementation, especially how they play a role in human health, longevity, and performance. In his free time you can most likely find him lifting weights at the gym or out hiking through the mountains of Colorado. He will also host the upcoming BioKeto podcast. You can connect with him on Facebook (https://www.facebook.com/elliot.reimers) and Instagram (@eazy_ell)
I had heard horror stories about how bad ketone esters tasted (like “rocket fuel”!) so was prepared for the worst. I followed their instructions and drank the contents of the bottle in one gulp, then chased it with a sip of sparkling mineral water. While not the most pleasant aftertaste, the flavor wasn’t any worse than after a shot of well tequila. Within 15 minutes I was already well into therapeutic ketosis, and after 30 minutes my ketone meter displayed a “HI” error message (meaning my level was greater than 8.0 mmol/L)!
Ketones are naturally slightly acidic, so the combination of BHB with sodium acts as a bit of a buffer to this acidity. Ketones will also naturally act as a diuretic, so you lose salt, potassium calcium and magnesium, and it is generally encouraged to increase sodium intake with ketones. The addition of sodium to the product will replenish this salt loss.
Yes — you read that correctly — 24 hours of intermittent fasting without any resistance training and these subjects were able to preserve more muscle mass than the subjects that ate fewer calories every day without fasting at all. This finding contradicts our common sense, but when we dig deeper into autophagy we can find the mechanism behind this result.
This is an excellent resource. Thank you for all the work and resources you found. i had never even heard of Adkins 72. I am keto but I always let Sunday be my high Carb cheat day.So im learning from this blog how to get back in ketosis in 24 hours after my 4pm meal on Sunday The Lords & family day. So im 25hr fasting. I would like to reference this article on my blog, thanks for helping me on my 100 lb lost journey.
Glucose and BHB went down slightly throughout the effort and RQ fell, implying a high rate of fat oxidation. We can calculate fat oxidation from these data. Energy expenditure (EE), in kcal/min, can be derived from the VO2 and VCO2 data and the Weir equation. For this effort, EE was 14.66 kcal/min; RQ gives us a good representation of how much of the energy used during the exercise bout was derived from FFA vs. glucose—in this case about 87% FFA and 13% glucose. So fat oxidation was approximately 12.7 kcal/min or 1.41 g/min. It’s worth pointing out that “traditional” sports physiology preaches that fat oxidation peaks in a well-trained athlete at about 1 g/min. Clearly this is context limited (i.e., only true, if true at all, in athletes on high carb diets with high RQ). I’ve done several tests on myself to see how high I could push fat oxidation rate. So far my max is about 1.6 g/min. This suggests to me that very elite athletes (which I am not) who are highly fat adapted could approach 2 g/min of fat oxidation. Jeff Volek has done testing on elites and by personal communication he has recorded levels at 1.81 g/min. A very close friend of mine is contemplating a run at the 24 hour world record (cycling). I think it’s likely we’ll be able to get him to 2 g/min of fat oxidation on the correct diet.

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