The Under Armour Women's HeatGear Armour Leggings are another popular choice for women's tennis base layer bottoms. These leggings are made with Under Armour's HeatGear fabric, which provides excellent moisture-wicking and breathability. They have a compression fit that supports your muscles and reduces fatigue during long matches. The leggings also feature a wide waistband and a hidden pocket for convenience. Whether you're playing a casual game or competing in a tournament, these leggings will keep you comfortable and focused on the court.