Possible Clues:

• Gymnastics exclusively outside in public
• In frank and candid manner
• Only about a third of the people, frankly
• In a non-confining way
• Just set about exercises without secrecy
• Frankly, without concealment
• Sans stealth
• Just gathering Philistine's clothing in public view
• In frank, candid manner
• Taking exercise inside, but not in private