While many adults belong to the Life of Riley school of vacationing, others find sports camps, schools and outings more to their liking. For this latter group, the word "leisure" takes a backseat to "learn," whether the sport is tennis, golf, racquetball, whitewater kayaking or canoeing.

Certainly some of these vacation/learning experiences have their luxurious aspects. A long-stemmed rose and morning newspaper, for example, come with breakfast at the posh John Gardiner Tennis Ranch in Carmel Valley, Calif., where approximately a week's worth of instruction, food, lodging and amenities are served up for about $1,500. But for those who prefer to rough it on a Sierra Clup knapsack trip, $100 to $150 entitles one to a turn at daybreak "kitchen" duty (and a pot scrubbing stint afterwards).

Frills or no frills, an increasing number of sports-minded vacationers share a desire for stimulating, productive activity that sends them off to bed or sleeping bag tired, but satisfied.

While sport camps do not offer undiluted leisure, they are a refreshing change of pace from the workaday world. Youngsters might balk at both morning and afternoon drills, videotape sessions and lectures, but adults seem eager for concentrated instruction.

Camps and schools offer students as opportunity to immerse themselves in a sport they may have previously pursued in a piecemeal fashion.

"One of the big advantages to attending a school," says Paul Menneg, supervisor of Gold Digest's three-day and full-week courses, "is that it puts the individual in a captive situation. A person devotes a lot more time to a sport this way than he or she would otherwise."

When people have spent more than $1,000 for food, lodging and teaching at one of Golf Digest's full-week packages, they're determined to get their money's worth, Menneg adds. "We only had a half a day of instruction when the schools first started," he explains, "but it didn't work. Even if you try to give the students an hour off, they'll just use that time to hit more balls. Now we go from 8:30 t0 5:30 straight."

Because some students hit more shots in a day at the school than they've hit during their entire previous golf experience, pupils are sent conditioning suggestions a month before their arrival.

One of the bill selling points of a sports vacation is that it goes on giving pleasure. The Killington (Vt.) School of Tennis, for example, bills its instructional package as "The Tennis Vacation That Never Ends," indicating that what's learned during five days "will be yours to enjoy till you hang up your sneakers."

The pointers picked up at a tennis camp sometimes take a while to digest, so positive results may not be immediately apparent. In fact, the opponent who beat you, 6-3, before may do so, 6-0, until your new skills take hold.

In recent years, ski resorts have gotten into the act by offering tennis and golf schools to keep busy during the summer. These areas generally offer a spectacular backdrop for instructional sessions, inn or condo-style accommodations and a social sampler of get-acquainted parties, barbecues and the like.

The Killington Ski Resort, a strong believer in "lifetime sports" and "action/learning" vacations, is perhaps best noted for its ski school, which pioneered graduated-length-type instruction. Now the same accelerated teaching philosophy is used in golf and tennis. Five-day packages run between$325 and $350, with two-day sessions available for less than half the cost.

While some sports schools and camps are headed up by "name" pros, Killington prefers to sell its approach to teaching rather than the credentials of its teaching faculty. At other schools, though, the appeal may be to learn the short game from Bob Toski, one of the foremost golf teachers in the country, or the importance of topspin from former Wimbledon champion John Newcombe.

Most sports camps have relatively low student/teacher ratios and divide pupils by skill levels. Beyond these similarities, however, the differences are many, and vacationers are advised to shop around for the camp or school that best suits their needs and budgets.

For those who yearn to soak up the great outdoors there are opportunities galore to join kindred spirits in hiking, camping, mountain climbing, bicycling, rafting and any number of other adventures.

Without question the outdoor experiences that consistently elicit some of the most glowing endorsements are white-water trips.

Fastwater Expeditions, a family-owned outfit in Boulder City, Nev., is one of the leaders in this field. Since 1966 Bill Belknap has organized trips down three Western rivers. Participants learn to maneuver their individual boats through rolling canyon waters. No previous boating experience is necessary, and one needn't even be a strong swimmer or veteran outdoorsman to go on these five-to 14-day trips, which range from about $300 to $750 per person.

Not everybody, of course, is inclined toward such total participation in a white-water experience. These people may prefer to ride large rubber rafts, the Greyhound buses of wilderness river travel.

Northern Whitewater Expeditions of Rockwood, Maine, is one enterprise in the business of rafting novices, most of whom have to participate as paddlers. With a bare minimum of practice and instruction, teams are ready for their day-long trips on the powerful waters of timber country. The price, which includes a lunch on river, ranges from $20 to $65 per person. Advanced reservations are a necessity and a liability release form must be signed before heading down-river.

The Sierra Club offers both kayak and raft trips, as well as canoe adventures that take explorers into regions ranging from the Okefenokee swamps of Georgia to the Scenic Rivers in Wisconsin and Minnesota.

This conservation-oriented organization lists well over 200 outings in its annual catalogue. The outings are intended to educate people on the proper use and enjoyment of the wilderness. To go on them, one must belong to the Sierra Club (a year's membership is $25).

The array of outing options runs the gamut from "wilderness threshold trips" (camping for families with young children) to bargain-basement "service trips," which combine pleasurable backpacking with conservation work. There also are burro and bicycle trips, plus all sorts of camping and hiking outings to choose from.

Although some trips are strenuous and others may be limited to highly qualified participants, the Sierra Club is not in the business of character strengthening.

Instead, it cultivates nature appreciation and caters to action-minded vacationers who say, "Forget the chaise lounge, room service and air mattress. Get me off my duff and on my toes."

This is one desire sports camps, schools and outings are more than happy to accommodate.