Stay Motivated: Mix Up Your Fitness Routine

Bike riding can be an all-weather change to your exercise routine. When it's dry out, cycle in a local park, along specially marked bike lanes, or with a cycling club. In rain or cold, use a stationary bike indoors. You might enjoy joining a stationary bike or spinning class, in which a leader takes riders through a routine.

Cycling is a non-weight-bearing exercise, so it's easier on your joints. To avoid other injuries, make sure you're on a bike that's sized and fitted correctly for you. It's best to get help with this from a knowledgeable person (bike shop staff or cycling club members can help). There should be a little bend in your knee when the pedal is in the down position. Always wear a helmet when biking.

Exercise in—and on—the water

Summer's a great time to mix up your routine by adding water activities.

Take the plunge and you may discover some muscle groups you've been neglecting. "Swimming is a different kind of exercise than walking. It primarily works the upper extremities, whereas walking is lower extremities," says Walter R. Thompson, Ph.D., FACSM, professor, Department of Kinesiology and Health, Georgia State University. If you like keeping track of your distance, swim laps in a pool. Swimming just for fun—in a pool, lake or ocean—also adds exercise benefits.

Water provides natural resistance, but more gently, since impact is lessened by buoyancy, says Bushman. That's part of the reason that water aerobics classes have become so popular, especially with women who may be overweight. She also suggests deep water run training, in which you wear a buoyancy vest or belt and use running motions while the buoyancy device holds you up in deep water. "It's non-impact, because you're not touching the bottom of the pool," Bushman says.

Canoeing, kayaking and rowing give you a work-out on top of the water. Bushman enjoys open water kayaking, which is done on a lake (so there's no river current to help you along). It builds core muscle strength in your arms, torso and legs.

Many river locations offer canoe, kayak and even rowboat rentals in hourly increments, so you can try one for as lengthy (or brief) a time as seems comfortable to you. "It's good exercise," Thompson says. "If you want to introduce variety, as a single-day substitute, instead of going for a walk, go for a paddle."

What variety can do for you