Welcome to The Fast Diet › The official Fast forums › Body › Benefits and side effects › Feeling incredibly tired, does any body else feel this too?
This topic contains 6 replies, has 5 voices, and was last updated by daisybouquet 12 months ago.
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29 Mar 19
I am 74 and a regular visitor to the local gym where I do 3 classes a week, and I also do some weight training. I have been on the fast diet for 4 weeks this coming monday, and have lost 5 lbs. However I find that when I go to my usual gym classes I feel ridiculously tired and weak!!Does this happen to everyone or is it my age? It’s very depressing because I used to enjoy the exercise, but feel reluctant to go now which is silly. Any comments/reassurance would be very welcome.
Well done on losing 5lbs.
My first thought is that you’re not drinking enough water. I know that when I first joined the gym I almost fainted a couple of times after my workout as I felt so weak and I suddenly realised it was lack of water.
We get most of the water we need from our food not from what we drink and if you are exercising you need extra water. Try drinking a glass of water immediately prior to your class and another one afterwards and see if it helps.
I just finished my 4th week on the fast diet also and have lost about 4 pounds. I was very tired the first three weeks, especially the day after a fast day. It has started getting better this week.
This is the second time I’ve followed the Fast Diet so I remembered from last time that I would be very tired the day after a fast day so I was better prepared.
Like Amazon said, of course check to make sure you’re hydrating but it could also be that it takes a while for the body to adjust to burning your stored body fat for fuel instead of relying on the food, particularly carbs, that we usually have a constant supply of. But it will adapt! It can take 6 -8 weeks for some people to become efficient at utilizing their stored body fat.
Also, you may need a little extra sleep during the adaptation process. It’s hard work for your body to re-wire it’s energy system so to speak and it’s hard work for it to lose weight. I try to give myself an extra hour of sleep on the nights I’ve had a fast day.
Lastly, it could be that you need to take in a little salt on your fast days. We lose quite a bit when we are hydrating and fasting. For me a cup of bouillon really does the trick. I’ve also just mixed 1/4 teaspoon of sea salt into a glass of water with the juice of half a lemon and in about 20 minutes felt significantly better!
I’ve heard from other people that exercise starts to feel good again around week 5 or 6. I think what you’re experiencing is quite normal! Hang in there! 5 lbs is fantastic!
Hopefully your energy returns soon! I had a very successful fast day yesterday but told my husband before bed last night that I was expecting to feel pretty tired today. I did need an extra hour of sleep this morning but now I feel quite normal and my energy level is great! I think I’m through the worst of it.
Thank you so much for the extremely helpful reply Kerry Ann, and when I finish writing this I shall go and mix the suggested salt solution ( in both senses of the word!)
I am relieved to hear that you have experienced the tiredness, and that it will pass, and also you have reminded me that our bodies must be very shocked at the sudden withdrawal of carbohydrates! I failed to consider this, and it makes perfect sense.
I am also interested in the idea of an extra hours sleep, something else that had never occured to me. I shall try to do that too.
All in all I feel that I have expected too much from my (ageing) body.
PS I had the salt drink about 20 mins ago, and I really feel it’s working!
Hi Yvette I used to feel tired, lethargic, couldn’t concentrate to the point of not driving ,
and got a lot of headaches on my fast days as I am a migraineur, however this all went away when I changed my fast day to the following:
Begin the first FD meal at dinner, go to bed and don’t eat your 2nd fast day meal till lunch next day. Too easy as I’m asleep during the fast time!
Have healthy afternoon snack
Then have normal dinner( I don’t do carbs at night)
I always have low GI whole grain carbs and high protein in my FD meals as this definitely keeps me going longer
I still eat really healthy on the non FD (no junk food)-but don’t restrict how much.
I found this advise on the 5:2 forum, and it really works well!
Ive lost 5 kilos in 6 weeks
With regards to the exercise, I used to go to the ladies gym or walk 30 minutes on fast days and feel terrible all day after it- but I don’t feel that anymore as I am eating again by lunch time.
Also having healthy snacks that don’t overdo my calorie count helps combating low blood sugar levels during FD.
I actually do 550 cal and sometimes 600 and I still have lost the weight.
I only weigh myself once a fortnight as weight fluctuations occur daily, that can disappoint me if I weigh myself too often.
Hope this helps you work out what’s best for you as everyone responds differently.
30 Mar 19
Yvette! I’m so glad to hear the salt water helped some and hopeful that the other things will help too. I know what you mean about expecting too much from aging bodies. I’m 51 so you have a year or two on me yet 😉 but i do the same thing.
I’m really excited to be using the 5:2 again because it works so well! I hope you finish with this transition phase soon. I’m sure your energy will be back up in no time!
@annelt….did you say that you fast from lunch to lunch then? And wow! 5 kilos in 6 weeks!?? I usually do dinner to dinner but lunch to lunch might actually be even less distracting. Although, it has definitely gotten easier.
15 Aug 19
I tried intermittent fasting and found it very hard going. I too, felt tired, with tired muscles, despite my efforts to put some energy into my walking. After just a short period of time (perhaps no longer than after two weeks’ 5:2 dieting, I felt that I had low blood sugar, and was amazed at the difference after munching just a small bag of McDonald’s fries. I quickly perked up and the misty vision cleared up. I felt I was back in the land of the living. I could even walk uphill with ease.
Since then, I’ve intermittently fasted by missing breakfast, and sometimes lunch, trying not to overeat by making up for it at dinner
but I can’t say I’ve felt alot better – except on odd occasions when I don’t feel hungry, and don’t feel like eating, or doing much at all when ‘fasting’ doesn’t seem to bother me – otherwise it is a horrible regime. So perhaps it’s better to let your body tell you what it feels like…
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