Like others have said it sounds like balls-to-the-wall-max-effort post run pain to me.
I tend to follow the a routine and I find it helps. My long runs are on Sunday and I usually pace about 80% effort. On Monday I rest and then on Tuesday I will go for a very short and light jog and combine with some stretching, strength or yoga type exercise.
The rest of the week I will do a few more runs at higher intensity but shorter distance than my long runs.
When training I always have a nice dull ache in my legs but it always feels like a nice tiredness. I would never call this actual pain.
How do they calculate £1 per runner per run of damage? That would be over £10k per year of maintenance? Must be an amazing park......
It smells of a parish council trying to scam some extra funding with a grant out of the county council. I am not sure they would be allowed to enforce parking charges and keep the income themselves (parish councils do not normally do that).
If they were genuinely concerned about damage I am sure that if they asked to put some collection buckets at the start a couple of times a year and ask for contributions I am sure they would collect all they needed.
If I am running 13 mile I will take a gel around mile 9-10. Its not completely necessary but I feel it helps, especially post race recovery.
However if you are struggling with them it is best not to bother. Use your training to work out what it is you are trying to fix, are you using gels because you think you should or are you trying to fix something?
I am not an expert on a no added sugar diet but maybe that is one area you should look at. One of the benefits (I find) of running is being able to pretty much eat anything I like.
In my opinion everyone can find 30-60 mins of time twice a week to exercise. If you are unable to, then you either are not motivated, supported or disciplined enough. Look at your calendar, speak to your friends & family and work out how to make it happen.
If you are very overweight (I understand I have been there) a cheap static bike in front of the TV is an excellent way of building a base level of fitness that makes running more doable
If I do an especially long on a Sunday I find a 20 min jog on a Monday night loosens everything up again. Generally though I cannot see much point in exercising for less than 30 mins, Too much hassle, changing, showering, etc.