Go to a physiotherapist, get a proper assessment and a decent set of exercises to do based on that assessment, then do them!
Lots cheaper and better to do it now, before you get a serious problem due to the compensation, rather than wait until it leads to a stress fracture or other serious injury (speaking from experience...).
Self-massage those calves. Get a bit of oil (coconut oil for cooking will do, also baby oil - anything that smells okay to you!) and massage your calves, using both hands on each calf and making sure to get both parts of gastrocnemium (the larger, outer calf muscles) and soleus (smaller and deeper, a bit lower, in the centre of the back of your calf. Massage at least twice a day. Go back to using your old shoes. If you haven't taken several days off running, do that. Note that it's better to rest now, sort the calves out, possibly get behind on your training and use a run-walk strategy if necessary for the half marathon than to try to push on now, cripple yourself, and not be able to run in October at all. Good luck!
marty:thanks. Yes, I've done Beachy Head before (that WIND!) and enjoye it. I'm just trying to decide whether working up form my present level (9-mile LSR last weekend) to that in under three months is vaguely sensible after a stress fracture. Should probably be okay if I don't try to race Beachy.
Re. a 50-miler prior to Comrades, it depends: in 2013 I set myself the challenge of five 50-milers and ran Thames Trot, SDW 50, NDW 50, Lakeland 50 and Ladybower 50... I've been wondering about tackling both Comrades and Lakeland 50 next year, if I can get a place for Lakeland 50, and I would certainly have been doing SDW50 if it didn't clash with a work event - apart form being trail rather than road it's similar terrain and I hope to do lots of training along SDW once I get my mileage up.
Hi Matt, Welcome! Pretty much any official marathon or ultra should be fine. I did the Saxons, Vikings and Normans Dymchurch Marathon and that was accepted. Ensurance life events tend to be over rather than under stated distance- at least, that's my experience from the Sussex Coastal Trail series earlier this year.
Regarding hotels, it depends on the hotel. Rooms in the Hilton get pricy, while e.g. Belaire Suites (on the coast, very comfortable) stays much more reasonable - book through e.g. Booking.com and you can cancel any time to three days before without penalty, so if a better offer comes up you can always switch. Now if you wanted to book a hotel in Pietermaritzburg... you're probably a couple of months too late!
I'm also back running again now, finally, including a great nine-mile woodland trail run last Sunday (another blog post!).
Considering whether to enter Beachy Head Marathon and jog round it for fun, or whether that's too short a time to sensibly return to that length of run.
Will: everyone is different and no training plan is set in stone. However, I find it's worth looking at some plans to see the kind of volumes of running that would be appropriate. For example if you look at http://www.trailrunevents.com/ul/schedule-50k.asp for a 50K (31 mile) race they suggest reaching 56 miles a week including a couple of weekends of a 26-mile run followed by a 10-mile run. For their 50-mile schedule, it's 26/12 and 62 miles for the week. I sort-of followed these for my first ultras and found them helpful. But I also made use of some other 50K plans that looked quite a bit different e.g. http://www.runforthetoad.com/trainingprogram.html (sorry, it's in km not miles).