A friend reminded me this week about indoor rowing as a low-impact alternative to running. I had forgotten about rowing! It is a great whole-body workout, as I experienced a couple of years ago at a different gym. Of course, I wanted to know what effect rowing might have on bone density. Even though rowing does not involve impact, as running and jumping do, studies have shown that it can lead to significant increases in bone density in the lower lumbar spine. That's great news! Building up the spine seems to be one of the most difficult challenges, as few exercises target it safely. Don't have a rowing machine? Here's how to make your own. Or if you happen to have a kayak or row boat, all the better. Happy rowing!