4. Adequate exercise: Add Health includes measures of frequency and type of exercise at all waves of data. Types of exercise include school gym class, biking or rollerblading, organized team sports, strength training, walking or running, and aerobics. All respondents at all waves are assigned a value of 1 if they report any of the above activities three or more times in the last week. This is the minimum recommended amount of exercise for preventing cardiovascular disease among individuals of all ages.