Sore calf - 5 weeks before London Marathon

Question
Morning. I'm running my 4th London Marathon on 17 April. My training has been going great and I can comfortably run 16 miles with plenty in the tank. I've had tight calf muscles for years (it runs in the family) so I take great care with diet, stretching, warming down and I wear running tights. Yesterday, after 8 miles I felt a real tightening in the middle of my right calf and stopped immediately, went home and carried out the RICE process. This morning, I have no pain, just a bit swollen and tight. What can I do in the next 4 weeks to ensure I complete the race. I'm seeing a physio on wednesday and intend on swimming / cycling for the next month to ensure my fitness level remains. Very worried because I have a lot of people and charity counting on me. Your advice would be very much appreciated. Regards, Mark.

Answer
Hi Markt
I have used the up right stationary bike for my clients and myself for many years and .Every thing you can do on the roads you can do on the bike,you just go by time.I would limit your swimmimg since  the bike is so much more event specific to the muscular skeleton system.You won't lose your fitness level in four weeks.

All the best Mark
good luck

John