I think you always get the best feel good factor when you do weight bearing exercise, something to do with the release of certain hormones. (zestforever.com)
To get maximum bone building benefits, you should take part in 30 to 60 minutes of weight bearing exercises for and least 3 days per week. (exercise-fitness-nutrition.com)
Weight bearing exercise for at least 20 minutes three times per week is recommended. (bostonmamas.com)