Out of practice? Left for run, becoming vigorous (5)
I believe the answer is:
lusty
'vigorous' is the definition.
(I've seen this before)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for lusty that I've seen before include "Brawny" , "Healthy, strong, vigorous" , "Full of energy, spirit" , "Full-blooded" , "Full of life, energy" .)