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!
If your cardio training regimen is for the intention of improved fitness and performance, then it is recommended that you train three to five days per week for 20 - 60 minutes each day at higher intensities.