Exercising for a lifetime: Encouragement to keep going strong

Studies show that to keep bones strong, we need to keep exercising throughout our lifetime.  With years  between bone density scans, it's hard to know whether exercising is making a difference.  So how can we keep motivated?
Here are some thoughts:

• Exercise with a team or a friend or a personal trainer. 
• Think of dollars you spend on personal training, a gym, new running shoes, etc. as an investment in your health.
• Vary your exercises, but always try to include an activity that is  weight bearing and bone building, such as jumping, weight lifting, rowing, racquet sports, running.
• Include non-bone-building activities as warm ups, cool-downs, or as off-day exercise.  For example, I like bouncing on a mini trampoline.  The research is mixed and not convincing regarding its effect on bone density, but it's fun and may have other health benefits. And swimming is not weight bearing, but works many muscles, is easy on the joints, is fun and relaxing. Who knows, maybe someone will discover that it does benefit bones in some way.