This study presents a real-life insight into the lives of five seasonal endurance athletes who by virtue of their own curiosity wished to experience the effects of a ketogenic diet on their sports performance. Overall, participants were able to increase the substrate utilisation of free fatty acids, reduce body fat and experience positive health benefits, but their maximal aerobic performance was compromised. The reduced body fat can likely be explained by a resultant calorie deficit created by the diet, as participants reported enhanced feelings of satiety and a reduction in overall food intake. Perhaps a combination of all three mechanisms can explain the weight loss. A limitation of the study was a lack of energy comparison prior to, and during the study, which would have provided some clarity about these mechanisms. All participants had a greater fatty acid oxidation at a higher given intensity at the end of the trial compared to baseline.
Furthermore, this substrate utilisation alteration can be attributed to the change in diet as training was kept relatively consistent throughout the intervention. Our participants also had a higher oxygen cost at sub-maximal workloads due to the higher use of fat as an energy substrate. However, this did not benefit exercise capacity. Future research with chronically fat-adapted athletes is needed to investigate these micro-level mechanisms alongside performance outcomes. 2.3 times greater fat oxidation rate in the LCHF group compared with the mainstream dietary group, but also demonstrated no difference in resting and replete muscle glycogen stores between groups. Authors suggest a homeostatic muscle glycogen repletion mechanism arising from hepatic gluconeogenesis, which might serve to provide clues into why many athletes report optimal performance, anecdotally, when having eaten in an LCHF manner for extended periods of time. LCHF and mixed-diet athletes. In fact, glucose was produced endogenously to a greater extent in the mixed diet group, and was attributed to greater rates of hepatic glycogenolysis. Researchers concluded that gluconeogenesis during exercise may remain stable across a range of dietary regimes after an overnight fast, but that hepatic glycogenolysis is influenced by dietary carbohydrate.
Further exploration of fuel contributions to gluconeogenesis and the effect of different feeding protocols on endogenous glucose producing mechanisms is warranted. This is one of the few studies to report specifically on endurance athletes’ experiences of undertaking a ketogenic diet. However, they also reported experiencing benefits throughout the trial. However, further research is required to substantiate this within athletic populations. From a physical well-being perspective, the cases of improved skin, and the resolution of an ongoing prostate issue, were major points of discussion of benefits experienced. All participants were consuming high-Omega 6 industrial seed oils prior to the study (used as cooking fat and derived from processed foods). During the study these fats were replaced with coconut oil, butter and olive oil; i.e., fats containing minimal Omega 6 fatty acid content. Being a translational study, we followed up participants informally 12 months after the study concluded. They were all still competing in endurance events, and while not eating a ketogenic diet, none of them had returned to their previous high carbohydrate, low fat style of eating. Collectively, they reported that once the study concluded they gradually increased their carbohydrate intake until the point at which they felt their performance at high intensities return. They were still restricting carbohydrate and eating more fat than mainstream guidelines recommend, and reported having discovered the optimal macronutrient ratio that satisfied a performance, body composition and a health goal. This study had several limitations: Its design as a pilot case study, with no standardisation of training prevents any inference from being made to athletic populations. A lesson learned from undertaking this research, and a key consideration for researchers and practitioners, is to encourage a reduction in athlete training intensity and volume in the early weeks of embarking on a ketogenic diet. This will likely induce less early fatigue and other negative symptoms related to training, and allow for metabolic adaptations to occur in a lower stress milieu.
Your body can only utilize glucose as a fuel source for very intense exercise and if you aren't taking in carbohydrates, you'll have no glucose available. Therefore, the ketogenic diet is not for anyone who wants to lead an active lifestyle with regular workout sessions. 3. You May Suffer Brain Fog. Those who are using the ketogenic diet may also find they suffer from brain fog. Again, this is thanks to the fact your brain primarily runs off glucose. Some people may find after a week or two of using the diet they start to feel better as their brain can switch over to using ketone bodies as a fuel source, but others may never find they begin to feel better. All in all, this diet simply does not work for some people for this very reason. 4. Your Antioxidant Status Will Decline. Finally, the last issue with the ketogenic diet is due to the lack of fruit and vegetable content - your antioxidant status is going to sharply decline. Antioxidants are important for fending off free radical damage, so this isn't something to take lightly. If you aren't taking them in, you could end up ill in the future. So keep these points in mind as the diet comes with some risks. The ketogenic diet converts fat instead of sugar into energy. It was first created as a treatment for epilepsy but now the effects of the diet are being looked at to help Type 2 diabetics lower their blood sugar. Make sure you discuss the diet with your doctor before making any dietary changes.
0 Comments