I feel like I saw this on a nature doc, but can't find any references now. Wild dog packs defecate before hunting, but not for the energy boost. The zoomies are to ensure they leave the scent of their poo in the dust, to minimize the chance of the scent causing them to spook their prey. But a dog doesn't consciously know that, it's just a naturally selected behavior that has made them better at surviving.
Do not quote me on this, my all natural intelligence may be hallucinating.
Worst experience of my shitting life was when I didn't defecate prior to the monthly jog. Luckily I could squeeze through the fence of the golf club I was near, and it was early enough nobody was around to 'report' me, AND they had the course's bathroom door unlocked. Now I just exercise at home where there's a bathroom within safe jumping distance.