That's a good way to give your body a chance to recover... Cardio, Core & Flexibility everyday with strength training every other day. The ramp it up to focus on muscle groups... Remember for firefighting endurance is the more important part of fitness. Getting off the truck and climbing multiple flights of stairs while carrying equipment is more important than how much weight you can push on a weight machine. Skipping rope can really add to your endurance & cardio workouts.
Getting into the Gym and working out for fitness & endurance is only part of the Training Program. You also need to focus on Wellness & making healthy choices for training, the one thing most people miss in this wellness program is rest & recovery. You need to get your sleep in order to recover from your training.