FUN FACTOR: Once a week, skip the long, lonely endurance work and go play soccer, ultimate Frisbee, or basketball. Or challenge a friend to a 100-meter dash six weeks down the road. By focusing on sprint workouts leading up to the big race, you'll increase the power of your stride, which is helpful for hoofin' up hills.
GO FOR IT: The World Famous Mud Run at Camp Pendleton, in Southern California, involves charging over chaparral-covered hills, snaking through a sand crawl, climbing two five-foot walls with mud obstacles on either side, and crossing a 30-foot-long mud pit. June 1112; www.camppendletonraces.com » The half- or full-marathon routes of the Alaska Salmon Runs, in Cordova, take you past mountains, glaciers, and eagles. June 11; www.cordovachamber.com
FUN FACTOR: Combine two sportstrekking and golfto avoid the steep green fees at the local course. Take a few clubs and a bag of Wiffle-style golf balls to an open park and create your own course by picking out "holes" in the distance, whether they're trees, boulders, or signposts. Swing until your ball hits the object. And fer chrissakes, be sure to yell "Fore!" with every shot.
GO FOR IT: See how you stack up against the best at the U.X. Opena tour of ten-hole mountain courses at Bromley Mountain in Vermont and Colorado's Snowmass Mountain, where you'll be whacking real golf balls over steep, wooded, rocky terrain instead of fairways and greens. August 6 and September 17; www.uxopen.com » If staying on course is more your style, enter a speed-golf tourney, in which you sprint to each shot. The scoring: Every minute equals one stroke. So if you shoot a 72 and finish in 40 minutes, the final score is 112. Find a listing of courses that permit speed golf at www.extremegolf.com.
FUN FACTOR: During practice or to warm up before a game, turn this team sport into a one-on-one competition. Set up two lines of eight cones spaced out over ten yards. Pair off and race, dribbling the ball through the cones and back, slalom style. Winners advance to the next round until the end, a bragging-rights race between the final two.
GO FOR IT: Via the U.S. Adult Soccer Association, your local-league team can enter regional tournaments in all kinds of categoriesmen's, women's, over-30, coedthroughout the year, building up to the national championships in Dallas, Texas, August 57; www.usasa.com
FUN FACTOR: On long, slow pulls across open water, play around with stroke speeds and power100 strokes hard, 100 slow, ten fast, ten slow. Paddling with a fleet of friends? Hold point-to-point races every 30 minutes. Take turns picking a landmark in the distance, like a dock, inlet, or rock, and racing to it. Hold a best-of-seven series throughout the day. Loser buys dinner.
GO FOR IT: The Round Bowen Race, in British Columbia, takes you on a 23-mile loop around Bowen Island. It's billed as the longest single-day sea-kayaking race in North America. June 4; www.roundbowenrace.com » For a more leisurely cruise, head south this winter and slide into either the Bogey or the Bacall race, in the Florida Keys. The Bogey course takes you 13.2 miles around the Keys, while the Bacall route circles Florida Bay's Blackwater Sound for six miles. Held every year during the first weekend in February; www.kayakfloridakeys.com
FUN FACTOR: Riding solo? Start doing calorie-based time trials. Once a week, wear a heart-rate monitor that estimates the calories you've burned, then pedal hard for 30 minutes. Each week, focus on burning more calories rather than tracking your time or average speed, two measurements that can vary with the weather and terrain. If you're in a group, pick a turnaround spot with two equidistant routes to that point. Have each half of your group take a separate route. The last group to finish buys everyone's beer. Or swap routes on the way back and race for double or nothing.
GO FOR IT: The Mount Rushmore Century Ride, in South Dakota, takes you through the mountains of the Black Hills and into Custer State Park, home to the world's largest herd of North American bison. August 27; www.rushmorecenturyride.org » Knobby-tire fans should try the world's oldest continuous mountain-bike ride, Colorado's legendary Pearl Pass Tour to Aspen, a two-day, 80-odd-mile event that winds over a 12,705-foot pass from Crested Butte to Aspen and back. September 1718; 800-454-4505