I have been doing about 15 min on the rower after my workouts. Its about 3 minutes for warmup, then about 7-10 minutes of interval, and about 5 min for cool down. If anything, I have been putting on a little mass and losing fat. I stopped weighing my food though so don’t know exactly how many calories I’m bringing in though. I’ve been doing a day of total body + rower, then a day of usually dumbbell circuits, then a day off. I’m not putting on slabs of muscle, but I’m getting a little bigger, stronger, and leaner.
I don’t want to screw up your bulk or anything, but I think adding more intervals whether sprint, rower, or weight circuits are a good way to drop body fat while maintaining or adding muscle. It might be faster to focus on one or the other, but I don’t see anything thing wrong with following the middle road and doing both simultaneously.
If anything, you can give it a shot and if you notice strength or energy decreases, you can up your cals or cut back on the cardio.
Still, 4-5 intervals sessions plus lifting sounds like a lot to take on and it might be overtraining a bit, and cutting into your recovery.
…Hmmm, I guess after considering these options, I would have to agree with Zagman and say just cut back your calories on non-training days, and be careful not to go too crazy with the cardio. Its funny how things seem to straighten themselves up when you write out the options, not that I’ve ever really done it.