I am not quite sure what you are asking. The two are so different. The only ‘combo’ I could possibly envision is a Reiki session after exercise.
I would agree with Karin, unsure of the question. Are the two compatible? Yes. Reiki on different days or post exercise would seem appropriate.
Many fitness/body work modalities are compatible and highly recommended in combination for optimal strength, muscular endurance and wellness progress and for mind/body/tissue healing and restoration.