"Breaking Down" during exercise

I'm trying to determine how much my Parkinson's is responsible for me bodys reaction to exercise.

I was officially diagnosed in October 2014.

When training for the New York marathon in 2003, my calf muscles would occasionally cramp up after say 10miles. One day, after a particularly hard session the previous evening, my calf cramped up so badly that I couldn't walk. Ultimately I was treated for tendonitis in my achilles but here's the crunch ... despite recovering a lot of my fitness by cycling and walking, when I tried to run again, my calf broke down (badly) after less than a mile. 

I'm coming round to thinking that this is "condition related" rather than any particular bio-mechanical anomoly (or gait/technique for that matter), and wondered if any other runners, or ex-runners even, have had similar experiences?

A little worryingly, I had a calf cramping episode when cycling this week - the first time it's happened on the bike.

Hi

i m not a runner but try to walk everyday if possible. I ve recently been diagnosed with Achilles tendonitis because of tight muscles in my lower back, backside, hamstring, calf right down to the Achilles' tendon.

I am sure this is PD and am having gentle massage from an osteopath and a Bowen therapist which help at the moment.

hope you can get some treatment

bw.    Samdog