I've had several people claim that I'll get better results if I separate my cardio days from my strength days. Have people found that this makes a noticeable difference?
There is not simple answer to your question. It all depends on what you want to emphasize.

For some people, 30 minutes of running is alot, and training with weights on that day is out of the question. Other people spend an hour on cardio, then hop to the weight room and lift for another hour or 2. The thing they do first will get the most energy, and if they are in better shape, the second thing will not suffer as much.

Also, what are you considering cardio?
If it's low intensity, long duration, and legs only, that's great for endurance. But, if you do alot, like over 30 minutes, and you are in shape for it, then you may as well finish off your legs that day with weights and completely rest them the next day.

If you are considering sprint intervals your cardio, then that is most times anaerobic, and is not the same. Some jump rope for cardio, and for some it's anaerobic... that depends on their fitness level, and the efficacy of their technique. Self perceived exhertion is the key here.

I doubt if many firefighters are beginners, but I'll say it anyway: With people who are just starting out, I recommened alternating cardio days with weight training. On their cardio days, they do only (20 minutes at first) that and abs. On their weight training days, they do the entire body, 2-3 sets of each muscle group, and rest from resistance training the next. They train 5 days a week, 3 cardio, 2 weights.

As they progress, I break it into upper and lower body days, and cycle those with cardio days. That would mean day 1: cardio, day 2: upper body, day 3: lower body, day 4 rest. Abs can be done very day.

Later, I might put them on a push-pull routine: day 1: cardio, day 2: chest, shoulders and tri's, day 3: back and bi's, day 4: legs day 5: rest. Abs can be done every day.

Still later, I might break it down to: day 1: cardio, day 2: chest, day 3: cardio, day 4:back, day 5: cardio, day 6:legs. Abs every day, and rest on day 7.

If you really want to increase strength, I wouldn't use your valuable time doing small muscle groups. Let's face it, when you do chest, you also get anterior delts, middle delts, and triceps. This is epsecially so if you train upper pecs with incline work. Then there is not real need to shoulders and tri's. It's not really functional in terms of what you guys do for work. You would always (at least try to) use more than a minor muscle group in your job.

Likewise, when you train back, you get posterior delts, and biceps in the bigger exercise. You are more apt to grow strength by just doing more back work instead of doing the smaller muscle groups. Again, you'll almost never use just your biceps or just your posterior delts in your job.

Days when you really work hard at major muscle groups, your cardio should be done last. You may not have enough energy to do it with all your might, thus the law of diminishing returns.

The strongest people spend most of their time doing the exercises that use the most muscle groups at one time. This causes the brain to release more growth hormone, and the results are better for functional strength. Mittleschmirtz had a great point in here a while back about picking up and moving very heavy objects... like those huge sand heavy bags they hang in gyms. This uses every muscle in your body, and is very effective for overall strength. These kind of exercises deserve an entire day off the next day... depending on how much you do, and whether you are used to it or not. People who are in good shape might want to do a light cardio workout the next day just to loosen up and pump the lactic acid out of their muscles... decrease soreness.

If you are going for looks, by all means, don't leave out the bi's and tri's and shoulders. Doing these separately will be more effective for that!

Super setting opposing muscle groups (without rest between sets) works well keep your heart rate in it's training sensative zone WHILE you are training with weights. This could then be considered "cardio", right? You may not need to do it that day, depending on how high and how long your heart rate was up.

Don't forget, you can do intervals: say of jump rope, and major muscle group work. Like: 1 minute of rope, and 20 smith machine squats. Keep increasing your weight every squat set, and keep jumping for a minute each rope interval. Then you get cardio and strength for legs at the same time. Do 8-12 sets. Try not to rest between sets. This could also be considered cardio too, right? AND resistance...

Another big thing is cross training. Try to change the exercises you do often. It will shock your muscles and stimiluate growth hormone release. You will respond by growing bigger and stronger, more adaptable and functional muscle.

The last point I'll make is that to increase strength, you really need to work very hard. Don't go to failure at the top end of your weights on every exercise every time... but probably every 3rd time. I also recommend going from say 16-18 reps, lowering that number by 2 each set, as you increase your weight each set. There is no reason not to go all the way down to 2-4 reps at your heaviest set. Yes, I know that sometimes means 8 or 9 sets of any given exercise.

Oh, and stretching and resting are paramount.

I hope that's not too long winded. There are so many different ways to do it. Alot of them work. See what I mean by there is no simple answer? It all depends.

Dr. Jen
Author of Fire it Up! CPAT Training System