I had a very serious blood disorder myself, so I can relate.
You don’t necessarily need more cardio if you do this program properly.
If adding bone mass is an issue, than training in progressive resistance is your first step, but there are nutritional guidelines you have to put in place, too
You’re trying to add bone mass, not necessarily muscle, so you don’t need to do a lot of isolation moves or work to failure, but the weights must be challenging. Your bones grow in a similar fashion to your muscles, but rather than hypertrophy, you’ll be trying to induce osteogenesis.
The best approach for you would be a circuit training programme done 3-4 times per week. Concentrate on doing sets of ten to twelve reps of weights that are challenging, but not VERY difficult.Doing a circuit programme may also remove the need for cardio training, if you do the exercises in the proper order.
Try something like this, but modify it for whatever equipment you have access to.
Warm up with a couple of light sets of various exercises. Once you’re sweating a bit and you feel loose, go on to the core of your workout.
One set each of the following body part in rapid succession. The rapid pace and the bouncing from lower body to upper body will induce enough stress on your circulatory system to make this both anaerobic and cardio vascular at the same time. Your heart will have to pump blood all over your body to oxygenate your muscles.
Chest presses, leg presses (or squat), rows (or pulldowns-pullups),shoulder presses,hamstring curls, sit ups (crunches) and repeat three times.
Now you can add a little isolation, because you may start to poop out a bit. Working smaller muscle groups toward the end of your training will work best.
Biceps curls, triceps extensions or press downs, calf raises, side lateral raises, bent side lateral raises and repeat three times.
Since I don’t know what you have access to, you can look up any of these exercises in the HUGE database.
http://www.bodybuilding.com/fun/exercises.htm
http://health.netscape.com/story/2007/08/10/bodybuildingcom-exercises-guide-over-300-exercises
There are images and videos there that can help tremendously.
NOW! Part of the issue with osteogenesis that many people fail to consider is vitamin D. Most experts agree that the USRDA for vitamin D is entirely too low and doesn't take into account the elderly and people that don't get much exposure to the sun.
That said, you'll need calcium, vitamin D and even boron. Boron is a trace element that we need in order to utilize the calcium that we take in. Also, inulin is a dietary fiber that's shown great promise in improving calcium uptake. I get my inulin from Stonyfield Farms Yogurt. Four grams per serving and two servings meets the inulin requirements in line with the studies.