The best workout clothes, if you really wear them to workout.. are not obviously fashionable but are designed to make working out as comfortable as possible.
If you think wicking. Unfortunately, supposedly "wicking" fabrics are not natural. If you sweat a lot, clothing made out of fabrics containing polypropylene maybe a good choice for exercise, they should allow the sweat to be evaporated from the skin and do not soak clothing in theory, in reality, it does not always happen, I see runner in Nike Dry-Fit with big patch of sweat on their back all the time.
If you think natural sweat absorption, anti-stink and temperature regulation. Then you are at the right place. Natural fibers have to withstand variations in temperature and humidity for the life of the organic beings they originate from, natural thermal regulation: How a worm (silk), sheep (Merino wool), bamboo plants or Eucalyptus trees (Tencel lyocell) survive, they adapt.
The best activewear natural textile for us: Tencel™ Lyocell the ultimate fiber for sporting activities due to it's natural sweat management, anti-microbial and hypo-allergenic proprieties. The Austrian company Lenzing branded Lyocell fibers are derived from sustainable wood sources, created through an environmentally responsible process with low environmental impact. The pulp of trees is dissolved in a non-toxic organic solvent. The solution is then extruded through fine holes to produce fiber and the solvent is recovered in a closed-loop process, more than 99% of the solvent is recycled and reused.
Tencel™ Lyocell based fabric helps you to stay cool, dry and comfortable naturally. Clothing made from TENCEL have a luxurious texture, are softer than silk and cooler than linen. Tencel is biodegradable, breathable, and resistant to wrinkles.
Most importantly stay away from fabrics that don’t breathe. Never wear clothing made out of rubber-based or plastic-based materials, which keep sweat from evaporating and keep your body temperature too high during a workout. Also polyester clothing like plastic items will not biodegrade, are hardly recycled, and every wash releases plastic microfibers into waterways.
And don't forget, If you exercise outdoors or play seasonal sports, sportswear change with the seasons. If you are still not sure read Is lyocell breathable and good to workout in the summer heat? and Is lyocell good for cold weather
Remember that no matter what, you're still likely to work up a sweat during a workout. Or you don't work out HARD enough!