Biking is a daring undertaking anywhere in Russia, where drivers are unaccustomed to sharing the road with nonmotorized vehicles and bike paths are nonexistent. Half the year the roads are too slushy or icy for pleasant biking, but in summer, a cruise along any one of the city's embankments is delightful for experienced bikers. Try Rent-a Bike (7 Goncharnaya Ulitsa, inside the Kitsport store; tel. 812/717-6838; www.rentabike.ru). Bikes are available from 500 rubles per day; bike tours are also available.
This is a city of canals and rivers, and in the months when they're not iced over they offer a variety of boating options. Numerous private boats also ply the canals, offering rides for groups from 2 to 10 people. Rates are negotiable and vary widely, from about $20 to $100 an hour, usually set in dollars or euros, so it's worth your while to bargain or find a Russian speaker to help out. Safety features are generally good in the big tourist ferries and hydrofoils, but they can be negligible in the smaller boats.
Ice fishing is the sport of choice for Russian men of a certain age and temperament in the winter. You can catch a glimpse of them sitting motionless on the Gulf of Finland. Unless you have lots of ice fishing experience, this is a better spectator sport than participatory one.
St. Petersburg is just catching on to the gym concept, and only the biggest hotels have a Western-style health club. If your hotel doesn't, Planeta Fitness is a Russian chain with branches around town offering daily passes (tel. 812/777-2555; www.fitness.ru); before 5pm passes are about 500 rubles, after 5pm they're 900 rubles.
Russian children often skate before they can read. Watching a determined grandfather guide his grandkids along an icy pond in the winter can be just as fun as watching a big tournament. Any pond turns into an informal rink during the freezing season. Victory Park and Taurida Gardens have real rinks as well, and rent basic skates.
A White Nights jog along the Neva River is an unforgettable experience -- but your feet may never forgive you. St. Petersburg's stone streets, treacherously crooked and cracked sidewalks, and drivers unused to dodging speedy pedestrians make jogging a challenge. Your best bet is to hit the larger parks, such as Victory Park; even the smaller parks closer to the center of town such as Taurida Gardens or Summer Gardens can make for pleasant runs. Running during daylight hours is recommended, which is not a problem during the long days of spring and summer. Russians are not big on casual jogging, viewing it as the domain of athletes and not amateurs, so be prepared for perplexed looks.
The forests around St. Petersburg are a paradise for cross-country skiers, but downhill options are limited to resorts a few hours out of town. Some dedicated city residents skate-ski through the lanes of the bigger city parks, such as Victory Park. Cross-country ski rentals are available adjacent to the palace at Tsarskoye Selo, for royal rural sightseeing.
St. Petersburg offers a surprising number of options for thrill-seekers. Tandpem paragliding flights are available at the Uglovo airfield for a bargain 800 rubles (tel. 812/298-3751; www.glide.ru), and tandem sky-dives at the Kasimovo aerodrome from 4,600 rubles (tel. 921/865-6696; www.skydiving.ru). Alternatively, real extremists (or the outright bonkers) might like to try a parachute jump with Sosnoborsky Aeroclub: a short distance from the nuclear power plant of the same name. Tandem jump with instructor run 4,500 ruble, April to October only (tel. 813/692-5804; www.kummolovo.ru/eng/).