From Dr. Joseph Mercola:
Swim (But Only In Fresh Water)
“Swimming is one of the best exercises, working all the major muscles, but it poses the challenge of exposing you to the large amounts of chlorine that are in most swimming pools.”
Bike (But Be Aware Of Safety Measures)
“If you decide to bicycle for health, study all bicycle safety measures and be aware of the high risk for serious injury compared with other exercise options. Always, of course, wear your helmet.”
Run
“[Running] is one of the most efficient and inexpensive ways to stay healthy; the only equipment required is a good pair of shoes. If you decide to run, please recognize that most shoes will not last more than six months.”
