In reply to BikeClimbWalk:
Your calves have 2 main groups of muscle.
Gastrocnemius : attaches at the tendoachilles and the back of the knee on the femur. It flexes the knee and points the foot. Tightness will be mainly felt in the bulk of your mid calf.
Soleus: attached to the tendo Achilles and lower portion of the rear tibia. Points the foot.
It is not possible to stretch both properly with the knee straight, as tightness in gastrocs will prevent a full stretch of soleus.
I would try these stretches.( you are by your post doing this on the step)
1. Balls of toes on step, let heels drop until you feel the stretch in back of mid/upper calf. Hold for 30 secs to a min. Repeat x3 , 4x a day
2. Same position with feet, but let knees bend in a mini squat before dropping heels. If soleus is tight you will feel this in the lower posterior ankle area. Same dosage. Do both legs at the same time.
You've possibly upped your training/hills and this is aggravating them?
If you can contact Roadrunner5 on here, he's knowledgeable on training schedules.
Post edited at 18:27