Like much of South America, soccer (fútbol) is something like religion in Peru.  Kids play in the street, adults play in the parks, and when the national team is playing, the country shuts down.  Be sure to take in a game if you can: it's an unforgettable experience. Many of Peru's best players play for teams in other nations, as they can get a great deal more money, but fans back home still like to follow their careers.
While the peruanos are playing soccer, active visitors will notice that Peru is a paradise for adventure sports. Hiking, trekking, rafting, paragliding, sport fishing, rock climbing…you name it.  Some sports, such as sandboarding (cross a snowboard with a sand dune and you get the idea) are best done in Peru.
Hiking: Peru is one of the most mountainous of the South American nations: it also boasts diverse ecosystems from its western beaches to its tropical jungle lowlands.  The most famous hiking route in the Americas—the Inca Trail—covers much of the highlands, although the most famous section is definitely from Cusco to Machu Picchu, drawing thousands of trekkers every year.  The Salkantay loop, the Huayhuash mountain range, and the Cordillera Blanca are other popular hiking areas.  For experienced mountaineers, there are literally dozens of spectacular peaks.  The highest mountain in Peru, Huascarán, first climbed in 1932, is particularly popular.
Sport Fishing:  The world's largest black marlin, weighing a staggering 1,560 lbs. (702 kilos), was caught in Peruvian waters.  Still need a reason to come try your luck?  Peru offers excellent saltwater fishing on the coast, and excellent freshwater fishing in the Amazon.  Trout fishing is good in the highlands.
Rock Climbing:  Peru is full of rocks, many of which are suitable for climbing.  The big cities—Lima and Cusco—both have good rock climbing locations nearby.  Many travel agencies in these cities specialize in this sort of adventure tour.
Surfing: some archaeological evidence suggests that the first surfers were not Polynesian, but Peruvian.  Regardless, Peru features several top-notch surf spots, including Punta Rocas and Cabo Blanco, both spots on the world surfing championship circuit. There are good waves year-round in different areas of Peru's long Pacific coast.  Although surfing is catching on in Peru, it is still not as big a surf destination as, say, Brazil, and it is easy to find a secluded spot where you'll have the waves to yourself.
Whitewater rafting:  Peru's combination of high peaks and rainforest jungles creates a near-perfect environment for rafting.  The best known site is probably the Apurimac River, which features class IV and V rapids.  Beginners will probably want to try out the Urubamba River first, which is a little more laid-back.  Dedicated rafters may want to consider a several-day jungle rafting trip.  Guides and outfitters are generally very good, but it never hurts to do a little research on any agency you’re considering using.
Mountain biking: this sport is a fast-growing activity in Peru.  With countless canyons, valleys, mountains, and long coastal roads, it certainly has the goods.  Check with your hotel or youth hostel: many offer bikes to their clients, although quality can vary greatly.  You're more likely to find bike rental places in high tourism areas or in places popular with a younger crowd.  Check out bike trips to the Paracas Reserve, The Cordillera Blanca and in Pachacamac, not far from Lima.