For the dogs, lots of hikes & road work on gravel roads (toughens up the pads). We will get some waterfowl and sharptail hunting in before roosters opens in October, as well. I constantly adjust their intake of food to prevent them getting overweight in the off season.
I'm 62, and keeping in shape was a helluva lot easier 40 years ago. I walk as much as possible, as hunting roosters & sharps in ND requires a person be able to walk at least 2 miles a day in cover, and sometimes much more. Nothing more frustrating than hunting with someone who is done in for the day after hunting the first half a mile in cover.
I also shoot clay birds, increasing the frequency as the seasons approach. I don't shoot just trap loads, but also the loads I use hunting, as nailing a double with trap loads is way different than with a stiff hunting load like the Prairie Storms I favor. Yesterday after work, I shot a round of 25 clays with Federal Prairie Storm through my Citori Featherweight. Yes, 25 rounds of Prairie Storm in about 15 minutes using a lightweight shotgun like my Browning was overkill, but the Citori is new to my rooster arsenal for this fall and I'm still getting used to it. After I picked up hulls and cleaned the Browning, I took 3 Advil for the sore shoulder and recoil headache...