So here are some ideas to give the calorie burn to the dog, not you. Even 10 minutes of these activities (try for 20 minutes or more if possible though!) will give him a pretty decent workout before you put him in his crate and leave for work.
Fetch. Weimaraners are generally natural retrievers. To get the most out of fetch when you are short on time, have your Weim fetch up the stairs. No stairs? Get a Chuckit so that you can throw that ball far enough that he really sprints for his ball.
Biking. You bike, he runs. 10 minutes is a pretty good run for him in the beginning and you can work up your time. You should get a bike attachment (I prefer the Walky Dog) and put a harness on him, so he learns to pull. Once your Weim learns to pull, you won’t need to help peddle!
Find It. Use this game as described here. You can incorporate yourself in to this game or use a toy. This game engages the mind as well, so a short stint will usually do the trick. Again use stairs if you can for this one.
Play. Nothing wrong with a good ol’ play date with other well socialized dogs! Gotta love a tired pup!
Don’t forget the brain exercises! Mental stimulation is very important for a thinking breed like the Weimaraner. Boredom is always trouble so anything that engages their mind is going to stave off bad behavior. Training actually works best in short intervals, even 5 minutes! Thus, a great way to tire out your Weimaraner is to physically exercise him, and then follow it up with a short training session. Take the time to do this and you will find your Weim will be much more calm and behaved.