The only thing we really know with 100% certainty is that humans have been taking DMT for several thousand years. In 1990, two mummified human bodies were dug up near the Matanza River in northwestern Argentina. The mummies were very well preserved, both being adorned with high quality woolen mantles.
Just 30 minutes of swimming three times per week can boost your energy levels through increased metabolic rate. Exercising without the sweat. If sweating puts you off other forms of exercise, fear not!
How much cardio you do should be based on what your health and fitness goals are and what you are physically capable of doing. If you are trying to make a healthy lifestyle change then consider 30 minutes of moderate cardio (walking, hiking, biking) 5-7 days per week.