Classes, books and booklets abound to help you grow old in robust grace. Some suggestions:

Check with local YMCAs, Jewish Community Centers and health insurance carriers.

Write to national offices of these senior citizen organizations:

National Retired Teachers Association and American Association of Retired Persons, 1909 K St. NW. Washington, D.C. 20005.

National Council of Senior Citizens, 1511 K St. NW, Washington, D.C. 20005.

National Association of Retired Federal Employees, 1533 New Hampshire Ave. NW, Washington, D.C. 20036.

Or write to the National Health Information Clearinghouse, P.O. Box 1133, Washington, D.C. 20013.

Check out these books (among many others):

Be Alive as Long as You Live by Lawrence J. Frankel and Betty Richard. (Harper & Row, $12.95).

E Is for Exercise, free from your local Heart Association.

Don't Become a Pain Statistic, free from American Physical Therapy Association, 1156 15th St. NW. Washington, D.C. 20005.

In the Washington area, early birds may watch Senior-cize, a 10-part series to be broadcast on Channel 4 at 5:30 a.m. Monday through Friday, the weeks of Oct. 12-16 and Oct. 19-23. Betty Switkes, the exercise instructor, also conducts Senior-cize courses. For information, write Senior-cize, Penthouse Suite, 7316 Wisconsin Ave. NW, Washington, D.C. 20814.