You see them on the track at the local high school or college. Transistor radios pump Vivaldi into the their earplugs as round and round the lonely long distance runners go. Do 25 laps equal a sonata? Three miles a symphony?

The earphones are not for naught. Running in circles or even along the same old path can get monotonous. But transistors and ear-plugs aren't the only answer. For the jogger who logs in over two or three miles a day, a change of direction works wonders. You can cut out along trails that track rivers and span fields of wildflowers. The occasional hill-climb is rewarded: the lapping sound of water and the scenic sideshow take the mind off gasps for breath and aching feet.

Running new territory fires the engines, but it has a minor drawback. It's disorienting without your jogging route's familiar markers, the yellow house on the left, the tree with ivy that signal you're almost home.

With cooler weather bringing out bigger and better mileage in garden variety joggers, here are five two-mile to five-mile paths that are worth the running away from home.

The C&O CANAL is dirt rather than asphalt or cement, and so it's easier on feet, ankles, knees and backs. The body doesn't take as grueling a pounding. Besides that, the tow-path is a wonderful running course because it threads its way between the glassy waters of the canal and the throbbing beat of the Potomac. Views of the river are occasionally crowded out by trees, wildflowers, thick underbrush and graceful rocks. If you close your mind to everything but your senses, the smells and sounds of nature -- birds calling, frogs garumphing -- will carry you for miles.

The canal is not without its crowds. Walkers, bicyclists, joggers and dogs are on the move on the path all weekend long. Weekday morning and early evenings, however, joggers predominate. The unwritten rule of the road is to give fellow joggers a high sign when your paths cross. You can ignore everyone else, unless the dog looks mean.

To use the canal in Maryland, drive along the Maryland George Washington Memorial Parkway and a park at one of the parking turnouts for the locks. There's easy access to the canal across wooden footbridges. On the path, there are wood stakes every mile. Only a few entry points coincide with mile markers; two that do are Lock 7 and Lock 9.

The MOUNT VERNON TRAIL is a ribbon of asphalt running by the river and through the woods from Memorial Bridge to Mount Vernon. The surface is more even than the dirtcom-stones of the canal, but it's harder on the constitution. There are eight parking turnouts along the 17-mile route. One particularly nice run is the five mile stretch between Belle Haven and Fort Hunt Park. The run is across study wooden bridges that span valleys of arrow arum and pickerel-weed, daisies and wild rice. The river won't always be visible, but the wildflowers and march plants will be. Cars whiz by on the George Washington Parkway, and bicyclists compete for space. However, the slight uphill grade is a nice challenge, and the occasional downhils are restful. When running with a friend, leave a car picked at each end and run it straight through. Leave a picnic in the car at Fort Hunt and dine alfresco in a lovely 156-acre park that has picnic tables and a panoramic view of the river.

For a five-mile round-trip run, start at Fort Hunt, run to Mount Vernon and come back. You won't mind repeating yourself because the trip is along the river and through the trees.

For even more water, the three-mile triangular run of HAINS POINT in East Potomac Park is surrounded by it. The Potomac Channel along the other. The third leg crosses the land that makes up the widest portion of the Park. The run is on a cement walkway, but the only real competition for space is from anglers. Heading toward the Point, you may feel the run is endless, as the main visual point of reference is the Point itself and, for the first three-quarters of a mile, it doesn't appear to be getting any closer. t

when you run Hains Point, start on the Potomac side and go straight out, returning along the channel side. The prevailing winds blow downwriter; heading out on the Potomac side keeps the wind at your back. The channel side is more protected from wind and offers the amusement of admiring the fishing boats that line Southwest's piers.

There's plenty of parking on Hains Point near the tennis courts or at various turnouts along the running route.

In their epic efforts, Marine Marathoners include much of THE MALL, but there are plenty of short distance runs along the Mall as well. It's roughly one mile from the Capitol to the Washington Monument and one mile from the Monument to Lincoln Memorial. Like Hains Point, there's feeling of endlessness because the run is straight and the point on the horizon don't seem to get closer for a long, long time. The terrain, though, is relatively flat and comfortable. Try running on the grass rather than the sidewalks.

To add mileage to a Mall run, start at the Capitol, run the two miles to the Lincoln Memorial, then go down along West Potomac Driver to the Tidal Basin and back to the Capitol for a grand total of five miles. Make is six by adding the inland stretch of East Potomac Park to this run. For seven, it's the Capitol to Lincoln Memorial, across Memorial Bridge and south along the river to the 14th Street Bridge to the Jefferson Memorial.

Parking is catch as catch can along the Mall or on Capitol Hill. ROCK CREEK'S PARCOURSE starts at the top of a hill off the Calvert Street entrance to the Park and heads downhill for a mile. Joggers can keep going to the first automobile exit -- P Street -- for a 1.3-mile run. It's two miles if you keep going to the light at the Watergate. The surface is asphalt, and the tricky part of running the Parcourse is that it's all uphill on the way home. It's even tricker if you stop to do the chinups, balancing tricks and other assorted exercise which are features of the course.

Automobile fumes may bother you when you first set out, but eventually the trail crosses a bridge and takes a more secluded track behind a grove of trees. Be sure and look up when going under the first overpass: handsomely carved Indian heads decorate the facade.