Guardiola's energy? (3)
I believe the answer is:
pep
'energy?' is the definition.
(personal energy, vim)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for pep that I've seen before include "savings plan" , "Palindrome for vigour" , "Palindromic vim and vigour" , "Ginger; tax-free investment" , "Go" .)