As a doctor (not the GP mentioned above) and an asthmatic, I would definitely recommend using your ventolin pre-run - two puffs good technique and you should see a big difference.
The thing that has probably helped me most, however, is learning to breathe in through my nose rather than mouth. I used to get really wheezy but forced myself to start nose-breathing and now can do it for at least the first 15 mins of a run which changes everything. Basically the air needs to be warmed and humidified before going into your lungs, otherwise it is irritant and causes inflammation and, you guessed it, tight, burning chest. Your nose is much better at this than your mouth. It will feel hard at first as there is more resistance but just get yourself to do it every other breath or something and then build it up. Obv not if you are congested!!
Finally remember that you are built to exhale for twice as long as you inhale. The natural tendency as you get more out of breath is to cut off exhaling prematurely. This means you get hyperexpanded and find it increasingly difficult to inhale! A simple way to get the rhythm is 'in for two steps, out for four' although obviously you don't want to have to think about this all the way round - just get started then relax and forget about it until you get short of breath.
I still will get wheezy in really cold weather, but otherwise never have symptoms, and have actually come off all my preventer inhalers as the only thing setting off my asthma was running and the above measures have solved it.
Hurrah some other non-bionic runners! I'm in this group too, got down to 51:30 10K last summer but had a bit of a break (work-related mostly) and now floundering around the 55min mark again and lost a load of stamina doing most training on the treadmill at the moment due to shift patterns and that 12kmh speed feels a lot faster than it did.
Managed 5K in 24:45 back then too so will be aiming for 24 on the nose once I'm back up to speed (!)
Races... should definitely take the plunge I think as am sure that's the best way to push yourself that little bit further.
This was probably myoglobinuria - rather than haemoglobinuria/haematuria - caused by muscle breakdown products in the urine which do look very like blood and even test positive for blood on the dipsticks (although if your GP sent a sample to the lab to look under the microscope they would see differently). Rhabdomyolysis (muscle breakdown) is not uncommon after long races and is a classic exam question re marathon runners!
If you are still feeling rough two weeks on now you need to see your GP SOON - they will send a urine sample (although it's probably a bit late now) and do blood tests for kidney function, blood count and CK (one of the breakdown products). Most likely all of the tests will have gone back to normal by now and your fatigue is not linked, but it would be as well to check.
If it happens again after a long race, go to your local A&E and do the tests straight away - much more likely to yield a diagnosis (although be warned if positive they will probably keep you in for observation, your call!)
This has reminded me I have to get back to PROPER porridge instead of those naff sachets I got into the habit of on night-shifts this winter. Although I tend to swap to muesli in the summer - second the Dorset cereals vote.
My old magic recipe was 1/2 cup JUMBO oats (sooooo much nicer texture and flavour and no more expensive if you buy own-brand) to 1 cup skimmed milk, microwave 2mins (maybe Josh has a 3 gigawatt microwave but I've never had porridge explosion issues.
Best flavour combos - finely chopped apple (+/- raisins) put in before zapping and stir in some ground cinnamon afterwards, or chop up a banana and put that in for cooking then add mixed nuts after cooking (chop or break the biggies like brazils) - only tend to have this one post run when have earnt the nuts!
Loving the chocolate and peanut butter ideas (although it's gotta be crunchy!) but not so big on the coffee - prefer mine in a mug thanks!
Got my first sub-25 last week - 24:45 - super chuffed and bit surprised as my best prior to that was exactly 26 mins. Not done any races tho, wonder if I would be faster with some competition... Think TTTB and I are roughly on a par.
Now aiming for sub-24, am really more of a 10K and longer runner but nice to have a short loop after work and gain some speed... hoping it'll help my 10K time too!