One in eight people 65 and older exercise "vigorously" at least five days a week

According to a US Department of Health and Human Services report on the
Health Behaviors of Adults: United States, 2002–04 13.8% of people 65 and older exercise vigorously at least five days a week. A breakdown of the data shows that men are more likely to engage in frequent vigorous exercise than women and young people are more likely than old:

Age	Men	Women	Both
18-24	21.6	12	16.8
25-44	14.7	10.9	12.8
45–64	12.3	9.6	10.9
65-74	10.2	7.5	8.7
>=75	7.9	3.3	5.1

The authors of the 85-page report present other interesting data. For example, they found that the rate of vigorous exercise rises with income and education (which are correlated with age). They also observed differences based on race, region of the country, marital status and whether the respondent is from a metropolitan area, central city or smaller town.

The study defines a "vigorous" activity as one lasting at least 10 minutes and causing heavy sweating or large increases in breathing or heart rate.