So today is 15th July and I have been on the Keto diet for 18 days. I thought I would scribble down a few thoughts about what it has been like, especially as someone who is also training (Running and cycling) and how it has impacted in both positive and negative ways.
First a bit of context as to why I started down this road in the first place. I am a coached athlete and have been for the past 18 months. I race bikes (Time trials and crits) Run (5k, 10k, and half) and compete in mainly 70.3 triathlons.
Over the past 18 months my weight has dropped from 82kg to about 76kg. I know that i could loose maybe another 1-2kg to be really happy with were I would like to be both visually and as an ideal read weight.
During June, I had torn a muscle in my back which had kicked my training out of sync and as a result I had gained some weight. Now this was not significant, I got on the scales and they read 79.2kg. (With hindsight it was probably just one of those weird days when the scales go mad, but never the less it was a shock!) At this point I have to say that most of my issues with food and weight are probably mental and emotional rather than anything else. I immediately felt down and quite low. The rhetoric was “You are going backwards, all that hard work you’ve put in has now gone to crap, you are very soon going to be back where you started or even worse!”
I came out of the bathroom and said to Bex, “I am going to try Keto! I can’t continue in this direction.” She was great, she is constantly gracious when it comes to all of my new ideas and fads.
I have had a good mate who has been really successful on Keto so I tapped him up for some advice and he was great and really supportive. That day felt great as I was taking action and was happy that this would all be a good thing.
The first two days were epic, I was eating amazing tasting food, bacon, fried eggs etc… day 3 came and the thought of more salt kind of made my upper lip curl and a smile was forced through gritted teeth.
But it was all still heading in the right direction, I was reading up about all the positives and that’s what I was focusing on.
Also I was peeing for England, and drinking water like it was going out of fashion. I was popping an electrolyte tab in a few drinks as well as they say that the Keto flu can come and kick your ass about day 3.
I got into bed at the end of day 3 and thought, well if that was the Keto flu then I can live with that no worries. I had felt fine all day, maybe a little off the pace but no more so than a normal busy hectic work day.
Day 4 arrived and I could not have been more wrong. THIS was the Keto flu. I had no energy like NO energy. I was sleepy, foggy in my head and I also knew that I had a tough intervals session to do on the bike planned today. By this point I still had not said anything to my coach as I thought I could just wing it and push through whatever training had already been set a few weeks ago.

I spent the day thinking that if i just put this workout off a little bit longer I’ll have some more energy. It never came! I climbed onto the bike about 4pm for a session called over/ unders. This is were you ride two blocks of about 15 mins split into 1min at 105% of FTP immediately followed by 1 min at 95%. It’s a tough session when feeling great, I wasn’t looking forward to it. I did the 20 min warm up and then set off into the efforts, I managed the first min fine at 105% FTP but when the second effort came I just blew up my legs piled in and that was me done. I climbed off defeated. Wrote my feedback and confessed to my coach what was going on. Shame was a real feeling.
I had read that you loose some of your top end when on Keto as your body cannot convert the fats as fast as it does carbs for energy.
Day 5 and I had a long slow zone 2 heart rate ride to do. I was feeling a little more human this day and after a breakfast of bacon and eggs (again) I set off. The ride was good and after about 20mins I found a really good rhythm. I would usually take a light snack with me for a 2 hour ride. But I didn’t take anything with me at all and actually felt fine. Going on through Keto I found this to be the same, the long steady runs and rides I felt great as my body began to become fat adapted for the slower endurance type of events.
Day 6 and I had dropped to about 77.9 which I am guessing was mainly water weight. Your body dumps a load of water that it would usually use to burn carbs. So the weight loss is almost instant. This in one way is good as you can see results fairly quickly.
Day 7 was a 3 x 1 mile max reps. Again a fairly hard workout which taxed the top end and the results were again what I would have expected. I was not at my best but actually not as far of as I had thought to start with. Maybe things were changing for the better.
The week from the 6th-12th July were days 8-15 of Keto. I found that my energy levels were fairly consistent throughout the day rather than peaking and troughing. But my over all energy levels seemed down and I often felt lethargic. My Weight fell to about 76.4kg on average which is about were I wanted to be back to at the start of this with the hope that I would also be able to drop that bit extra. I never experienced that Keto high and clarity that so many talk about.
Again I did find that through that week my high end intervals were hard work and just about unachievable whereas my long stay rides and runs were fine.
As of today I have packed it in as I just felt the longer term effects were actually not allowing me to progress in my training goals which defeats the whole process. But I have learnt an awful lot from this brief experiment.
- It was a total knee jerk reaction to try Keto and mentally I could try and work on a better way of dealing with this.
- When it comes to dialling in nutrition for longer more endurance based events like the 70.3 triathlons I could see huge benefits from being fat adapted as a way of training and racing.
- It has given me a better awareness of food and how it is broken down into fats and carbs and understanding when and what to eat.
- I have lost weight in a fairly short space of time, but that has come with a downside in a lack of high end performance.
This is maybe something I would do again, but at the right time and for the right sort of effects. All in all nothing is bad if it has helped you learn and develop.