5:2 while marathon training

[elspethmcgillicuddy]

I'm hoping for some advice about fasting and marathon training. I started 5:2 a year ago and love it. I started running about 6m before I started fasting and in the past year I have run 4 half marathons with no problem.

I am running London Marathon and in the past few weeks since my long run distances increased beyond 14 m I have found I am a lot more tired with major energy dips. I am also finding myself binging a bit on feast days. On fast days I occasionally feel a bit woozy and out of it. This hasn't happened since I first started a year ago. I do run on fast days but up to a max of 5 easy miles (I've always done this). I also don't fast the day before my long run. I'm currently running 30-40m per week.

I guess I want advice on whether to give up 5:2 until after the marathon. I think it might help me train better and feel less tired in general.

If it helps I have a BMI of 22 and haven't lost any weight with 5:2 but have loved the ease with which I have maintained my weight. I had hoped to continue IF forever and feel scared at the thought of giving it up. Please help!

[BigChocFrenzy]

With the increased exercise, you might need to eat more carbs for fuel, i.e. tweak your macronutrient proportions

[BigChocFrenzy]

Long runs are tough when you are fasting, because your body struggles to burn sufficient fat as fuel for that longer period.

I suggest you stop FDs for a couple of weeks as a trial.
Instead do daily 16:8 or even 14:10, but aim to stay within TDEE.
If you are maintaining with 2 FDs, you may need to train yourself to eat to TDEE, say via mfp.

I recommend you cut right down on alcohol, sugary treats, junk food etc, to help your training and to keep calories within bounds.
Concentrate on protein, lots of veg, beans & pulses, fruit, nuts, plus complex carbs for sustained energy.

Weigh at least weekly, for a reality check:
Longer runs increases appetite, so you tend to eat more if you don't monitor intake - a surprising number of folk overshoot and gain weight

[elspethmcgillicuddy]

Thank you. I was supposed to fast today and normally would having nothing. I had some natural yoghurt, a banana and a small handful of nuts at lunchtime and felt SO much better. Think I will add in a small meal like this for now on fast days.

[lucjam2105]

I'm trying to do the blood sugar diet 800 kcal per day and train for 10k. I have no idea how you manage 5 miles on fast days! I'd leave off dieting until after the marathon. Is not worth messing up your marathon for a diet. You might never get a place again so treasure it and the training.

Good luck for the marathon.