i have trailhounds that i race. They only get a tiny bit of their favorite food when they finish a race as a treat, they don't get their proper feed til they get home. They all wear coats so they don't cool down too quickly and get muscle cramps. They don't all race 10 miles, some do 5 miles...
you dont say how old the puppy is. if its very young it could be missing its mother and the rest of the litter. a ticking clock and a teddy might make it feel no so alone at night