Jog is good to take part in altogether (5)
I believe the answer is:
nudge
'jog' is the definition.
(I know that jog can be written as nudge)
'good to take part in altogether' is the wordplay.
I cannot really see how this works, but
'good' could be 'g' (abbreviation) and 'g' is located in the answer.
'in altogether' could be 'nude' and 'nude' is found within the leftover letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'is' is the link.
Can you help me to learn more?
(Other definitions for nudge that I've seen before include "Jogger" , "Gentle encouragement" , "Poke gently with elbow" , "Gently encourage" , "Push (with a wink?)" .)