@taliesin: it probably has to do with the berth of your run and the position you have. i sometimes get that when i do interval training - say, 1min at 8km/h and 1 min at 12 and so on. if i'm tired, i tend to perform a walking movement in the slow segments, ie try to walk very fast rather than running very slow; i overwork the calf muscles and feel annoying strains. relatively small steps tend to put more effort on the lower leg, while relatively long steps (ie running movements proper) put more effort on the upper leg. since the bulk of muscle is in the thighs rather than calves, you have to make sure that when you start running you put more effort on the upper legs. note that this is not related to speed but rather to how you move; a good rule of thumb is trying to 'run tall' - very straight back, and lifting your knees as high up as possible. this type of movement weighs way more on the thighs than on the hamstring-calve system. you don't need to be fast at the start, you can adopt a small 'trot' and still not get hurt, provided you're actually 'running tall'. then, once your muscles are warm you can, if you like, have power walking spells as well to reinforce your calves (however, be sure it's not a half-hearted run, because that would damage your back).
this said, i've finally finished my back-to-form routine so now i get to do the fun stuff. i'm still going quite easy, but i managed to do my 3x12 arm curls with 6.5kg per arm on wednesday with no pain whatsoever, which means that if i work hard i'll go back to the summertime peak of 10.5kg per arm. i still look quite crummy, because i've burnt the little excess fat there was but muscle tone is not optimal... however, i'm optimistic. my scheduled groups for today are: back, shoulders, triceps.
this said, i've finally finished my back-to-form routine so now i get to do the fun stuff. i'm still going quite easy, but i managed to do my 3x12 arm curls with 6.5kg per arm on wednesday with no pain whatsoever, which means that if i work hard i'll go back to the summertime peak of 10.5kg per arm. i still look quite crummy, because i've burnt the little excess fat there was but muscle tone is not optimal... however, i'm optimistic. my scheduled groups for today are: back, shoulders, triceps.