As I did R3 today I noticed my right calf beginning to tighten and ache after 10 minutes. After 21 minutes it was getting painful (3/10) so I decided to slow to a walk to avoid the IC (I think that is the runners acronym for the “injury couch”). It seems to be getting better already.
The great thing about this forum is I remembered the phrase - “no such thing as a failed run - think of it as a practice run” 😁
Now I need to do that other forum recommendation - stretching on recovery days!