Throw your running shoes into your suitcase and then you can be off and running. Skip the treadmill and go for a run in a new city; it’s a great way to see the city in a completely different way. You can make it more fun by making it a game and challenging yourself to try to run more miles in other cities than at home. If you don't know where to go, just ask the concierge; they always have trail maps for routes of varying distances nearby.
If you don't want to run or you need to cross-train, use the hotel gym. But you might not always feel like going down to the gym -- and you don't always need weights or machines. You can build your own workout with suggested exercises from Sharecare Fitness. You can use pushups, sit-ups, burpees, squats... anything to get you started.
When you're entertaining clients/partners at dinners, sometimes it’s easy to stop counting your calories. But whatever you do, don't. When you're on the road is when you'll likely need your food log the most. Keep a close eye on everything you're consuming to make sure you stay within your calorie ranges. That doesn't mean that you have to be the fuddy-duddy on your trip, but you also don't have to go overboard. You'll feel better the next morning for it when you're working out in your hotel room.
The best way to keep yourself honest with exercising and eating right on the road is by making it social. Tell all your friends on Facebook, Twitter, and Sharecare. Another fun way to exercise is to make friends with the concierge or the front desk clerk and then tell him that you're going to go for a run; you won't want to walk by him later if you didn't run when you told him you would.