.......which probably has a proper name.

After a cycling holiday - lots of uphill cycling - alps / pyrenees etc, without regular cycling before hand.....

When return to proper exercise and go up a decent hill, I then come to go down a big hill and within a short time the thighs have gone completely solid ( Cramp? not sure what cramp in the thighs feels like ). It is unbelievably painful. Same happened every time I went out. Its a challenge getting off a hill with completely solid, rigidish legs.

Physio could not find nothing structurally wrong. Did get over it after a couple of weeks, stretching and building up the downhill. Stretching helps, until the next downhill.

No problems on flat / gentle undulations.

I now know of three other fell runners who have suffered the same after a cycling holiday and a return to the hills.

What is it? Cure?