How old is he & what "issues" were you seeing? 3 days of hunting isn't terribly much, but it's still significant & you should expect to see an impact of some sort on your dog.
And define "good shape". There's a big difference between being in decent shape & being in "hunting form". My dog's in good shape all year, but it still takes several hunts (cooler weather helps too) before he starts to get back into true hunting form, where he can hunt hard for a few hours, multiple days, & seem like it doesn't phase him (while hunting anyway). That said, at night after hunting, he's still pretty wiped out, which is normal. If your dog is middle-aged or older & seems stiff/sore in the evening &/or morning, here's something that's helped me in the past. Aspirin in the morning before hunting & in the evening afterward. Buffered. 5-10 mg per pound of body weight. (Always best to consult your vet.) That can really help with general sluggishness.
I've had great luck w/ PPP 30/20. Plenty of water while hunting is key, especially in warm weather. But if we're going to start hunting at 10:00 (SD shooting time), Ace doesn't get breakfast. He's really excited about his breakfast though, so I'll give him a little bit just to take the edge off & let him know I still love him. Much of the season though, we don't hunt until 2:00, 3:00, or sometimes even later. So he'll get kind of a medium-light breakfast those days. Evening meals are big enough to offset anything he was denied that morning, and then some. When I first learned about not feeding in the morning before hunting, it made a small but noticeable difference in my dog's energy level during hunting. It increased.