R&R is the military abbreviation for "Rest and Recovery," a term used when units are withdrawn from the front line to rest and rebuild their combat strength.
The material is relatively complex to produce, featuring thin strips on the front that make the pants flexible and stretchy. The back consists of small squares that are brushed up, which helps to retain some warmth. The way the material is made ensures that the pants won't feel too warm. They are therefore perfect for warm-ups or off-duty wear. You can also use them for training, as they are extremely stretchy and follow the body's movements. Once you put them on, you certainly won't want to take them off again.
Tech pants are made of functional fibers that are both stretchy and breathable, thus wicking moisture and sweat away from the body. You therefore get a super comfortable pair of multi-purpose pants, as they are equally suitable for both training and leisure.