Exercise may provide nutrition (5)
I believe the answer is:
pecan
'nutrition' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'exercise may' is the wordplay.
'exercise' becomes 'pe' (Physical Education).
'may' becomes 'can' (synonyms).
'pe'+'can'='PECAN'
'provide' is the link.
Can you help me to learn more?
(Other definitions for pecan that I've seen before include "Edible nut like a smooth walnut" , "of nuts" , "Type of nut" , "Nut of American hickory tree" , "Nut with sweet oily kernel" .)