Call well in advance if you want to play on a weekend in winter. The Army Golf Club (Delhi Cantonment. 11/2569-1972) is close to Delhi. To play against a backdrop of ancient monuments, try the 27-hole Delhi Golf Club (Dr. Zakir Hussain Rd. 11/2436-0002 Ext. 227 or 98100-03064) in the center of town.
The top hotels have excellent pools, but most are open only to guests. City pools should be avoided, as there's no way to judge the water quality.
If your hotel doesn't have a tennis court, reserve one at the Delhi Lawn Tennis Association (Africa Ave., next to Safdarjung Enclave. 11/2617-6140).
The international Sivananda Yoga Vedanta Nataraja Centre (neigh. redundant, A-41 Kailash Colony. 11/2648-0869) holds several classes daily.