Possible Clues:

• Loose-fitting top and bottom for athlete warming up
• Sportswear
• Loose sports/casual wear
• Possibly cut risk with a rest at the end, it's assumed, if exercising
• What an athlete may wear to follow match?
• What an athlete may wear in line with action
• Tailor cut a skirt as garment for athlete
• Retiring Welsh runner pursuing clubs in characteristic warm-up gear
• Course -- leading clubs perhaps put it on for training?
• In a truck, sit changing gear for practice