In November last year I decided I would experiment with intermittent fasting, or time-restricted fasting. Almost every day, for 50 days I restricted my eating to only 8hrs in the day, fasting for 16 hours. This meant I would usually finish dinner at 8pm, then not eat until 12pm the next day. If I went out and ate food until 9:30pm, then I would begin eating at 1:30 the next day. I talked about why I was doing this and the evidence for it here but essentially I had heard a lot about it and it’s benefits for health and figured, there aren’t really any risks, I’ll give it a go.
One thing many people asked me when I mentioned it to them was, “you don’t need to lose weight, why are you doing it?” I realised that fasting was most commonly seen as another weight-loss diet, it is the new fad. This question usually followed with me explaining autophagy and the health benefits of fasting, independent of weight loss, which again, I’ve explained previously.
How did it feel?
For the first week it was quite tough, I was getting pretty hungry around mid morning and consumed a lot of tea to keep myself full, which works a treat if you were wondering. Soon I became very used to not eating in the morning, especially if I was going to placement and not stopping until lunch time. This is when I noticed my first real issue with fasting. The post-fast insulin coma. I was having a massive lunch, to make up for not eating breakfast, usually with a lot of carbs to give me energy but come 3pm, I was exhausted. I was initially perplexed at this, but eventually realised it was because my body was so eager to start breaking down the carbs that it produced a heap of insulin to cope with the increased blood sugar levels, which increased my tiredness as the sugar levels dropped. On some days I experimented with eating lower carb, higher fat meals for lunch, or having lower GI carbs, both of which helped reduce the post-prandial crash. I also started having smaller lunch, not trying to play catch up, this also helped, and I would just snack throughout the afternoon on things like nuts and my homemade banana bread. The key for me was to eat healthily when I was, resisting the urge to just eat sugary or junk foods because I knew I’d feel much worse for it afterwards. I also found tracking my food in myfitnesspal very helpful to ensure I was getting enough food in me, without overdoing it.
The good things about fasting was that is is very convenient, you don’t need to allow time for breakfast in the morning, just grab a coffee or a tea and go. It would be a great way to lose weight because you make it through to lunch without eating and if you ate normally you’d be in a deficit, although it must be said I didn’t lose any significant amount of weight during the 50 days, but I was very conscious of eating enough. An unexpected benefit for me was even after I stopped fasting, I found that I was able to be much more flexible with my meal times. I used to always be hungry, i’d eat breakfast at 6-7am, have a snack at 9, and lunch at 12 then continue to snack until dinner, where I’d be insatiably hungry. Fasting helped me become much more able to be what we usually consider ‘hungry’ and just be okay with it, not needing to eat something immediately, helping me say goodbye to being hangry (most of the time). I think it’s worth just giving fasting a go for at least a week purely for this benefit alone, all other health benefits aside.
It wasn’t all good, when I began fasting I was not running very much, I was still in a stage of rehab where my sessions were <5km long and usually made up of intervals of easy running. I wasn’t expending a lot of energy during these and I would be doing them in the afternoons usually as well. A few issues began to arise when I started running more, six, seven or eight kilometres at a time and in the morning. I was feeling very flat and low in energy, with my heart rate much higher than it should have been. I soon came to the conclusion that I wouldn’t fast if I was training normally (which for me is >5hrs of exercise per week). Luckily, that nicely coincided with the 50 days of completed fasts. Over the past two weeks I’ve had a period of rest due to a recent niggle and a bruised knee and I’ve picked fasting back up. I noticed when I wasn’t training, I was still wanting to eat like I was training, so I figured fasting was a good way to kick myself back into gear and become okay with hunger again.
Overall I loved my time intermittent fasting, I think it’s a great strategy to be more conscious of what you eat, and when you eat it, as well as disrupt our psychological dependence on having constant access to food. I’m not going to continue it when I’m training a lot because it can be energy-sapping, especially when training in the morning, but for anyone completing <5hrs a week of training, I’d definitely recommend it to try, although it is crucial that you are eating sufficiently to fuel your training. Ultimately, it wasn’t life-changing, but wasn’t detrimental either and now I understand what it is like to fast, as well having picked up a few handy tricks along the way, and I’d recommend everyone try it, unless you’ve got a history of under fuelling your body, as an athlete or just as a person in general.
