Somewhat my NSV... really, my dog's NSV

So, I have been taking my dogs for fast/long walks every evening. I have a 13 year old Italian Greyhound, a 10 year old roly poly Shiba Inu, and a new member of the family is a 2 year old Lab/SharPei mix. We've had the lab mix for a month now. It took me a week of walking with her and coming home with a swollen shoulder to figure out she needed a Gentle Leader. Once I got that, it was night and day. Then, I added the IG to our walks. He is 13, but being a Sighthound, he can run circles around me any day. The Shiba Inu was a major abuse case and she lives with us on her own terms. I show her the collar/leash and if she turns tail and runs in the other direction, I don't force it. She's got a half acre fenced in, so can do what she wants.

Anyway, the last week, she's been asking to go for walks with me by sitting in front of the door while I get the other dogs ready and letting me put her collar on. However, she had a speed limit. 4MPH and no faster than that. It's still fast for her as she's not fat, but is on the plump side and 10 years old and out of shape. However, if I tried to get her to move faster, she'd just sit down and there was no budging her unless I wanted to pick her up and carry her.

The night before last was overcast when we went for a walk. A quarter of the way out (3 mile walk), it started drizzling, half of the way through, it POURED. Ginger, who hates getting wet and was now soaked, decided to scrap her speed limit and run with me. The other dogs obviously kept up. Last night, I was expecting her to reinstate her speed limit. But she agreed to run at intervals. We'd walk 4MPH, then jog for a while until she started lagging, then walk to let her recover, and then jog again. I was very impressed with her last night. She was tired when we got home and thirsty. She was very funny though and when I walked past the front door to the trashcan to throw poop out, she sat down and refused to walk away from the door. She was DONE WALKING.