I’ve had two stress fractures over the past six months — one in my foot and one in my shin bone. The doctor has put me off all activities that could cause pain (mostly weight-bearing). But that is having a terrible effect on my training schedule for the Boston marathon next spring. What else can I do that won’t interfere with the fracture healing but still keep me in shape?

The dilemma of staying active and fit in preparation for a marathon while recovering from (not one but two) stress fractures can be quite a challenge. Repeated stress fractures suggest there are some risk factors to pay attention to.

For example, diet and nutrition are important for bone strength. Studies have shown that adequate amounts of calcium and vitamin D are essential in this area. Women (and men) who diet and restrict calories in order to make weight or stay thin for their sport are often at increased risk for stress fractures. These same behaviors can also impair bone healing once a fracture has developed.

As for activities you can still participate in to maintain strength and cardio fitness, consider swimming, pool-running, and bicycling. Check with your physician first, but these are usually safe bets. Free weights or elastic tubing for upper extremity strength training is also a possibility. Overhead lifting can have a cardio effect when performed properly.

When you do return to training, you’ll want to gradually increase your training regimen. Avoiding another stress fracture requires good posture, good bone alignment, and balanced biomechanics. If there are any problems with hip rotation, leg length differences, flat feet or other similar issues, you may want to consider being evaluated for the use of an orthotic (special insert for your shoes).