Are there any exercise clubs, like people training for marathons, in the village of Wappinger Falls?

There are some gyms in Wappingers Falls, but they don't specialize in marathon training or anything like that. Probably the best you're going to get in that regard is by going to Planet Fitness in the Home Depot plaza and getting on a treadmill; since they have the capability of angling up to simulate hills, that might not be so bad. I don't know the first thing about running marathons but I'll guess that's a poor substitute for specialized training.