Table 1: Psychometric properties of scales used to measure correlates of physical activity (PA), including personal attitude, adult support, and environmental support among US high school students.

Scale name
no. of items
(score range)
Cronbach alpha
 questionnaire items

Attitude toward PA
5 itemsa
0.88When I am physically active:
 I enjoy it.
 I find it fun.
 It gives me energy.
 My body feels good.
 It gives me a strong feeling of success.

Adult support for PA
4 itemsb
0.80During a typical week how often does an adult in your household:
 Encourage you to do physical activities or play sports?
 Do a physical activity or play sports with you?
 Provide transportation to a place where you can do physical activities or play sports?
 Watch you participate in physical activities or sports?

support for PA
3 itemsa
0.58How much do you agree or disagree that:
 At home there are enough pieces of sports equipment (such as balls, bicycles, and  skates)
 to use for physical activity.
 There are playgrounds, parks, or gyms close to my home that are easy for me to get to.
 It is safe to be physically active by myself in my neighborhood.

aMeasured on a 5-point Likert scale: 1 = strongly disagree; 2 = disagree; 3 = neither agree nor disagree; 4 = agree; 5 = strongly agree.
bMeasured on a 5-point frequency scale: 1 = never; 2 = 1-2 times/week; 3 = 3-4 times/week; 4 = 5-6 times/week; 5 = daily.