Table 1

Characteristics of randomised controlled trials comparing exercise as a single intervention with no intervention

Study	Participants	Interventions	Duration
I, Intervention; C, control; WISC-R, Wechsler intelligence scale for children-revised.
Alpert 1990¹⁶	24 healthy boys and girls, aged 3–5 years	I: Aerobic classroom activity with music. HR 60–80%	30 min, 5 times a week for 8 weeks
		C: Outdoor play
Basile 1995¹⁷	53 boys and 5 girls from clinic (day treatment for emotionally and behaviourally disturbed children), aged 7–13 years	I: Jogging/walking	20 min, 4 times a week for 4 weeks
		C: Classroom activity
Ford 1989²²	97 healthy girls, mean age 19.8 years	I: Jogging, swimming or dance for fitness, or weight training	3 hours a week for 8 weeks
		C: Health science
Herman-Tofler 1998²³	52 healthy 3rd grade students	I: Aerobics 60–85% Vo₂max	25 min, 3 times a week for 8 weeks
		C: Traditional physical education, not aerobic
Hilyer 1979²⁵	120 students, mean age 19.1 years	I: Running	60 min, 3 times a week for 10 weeks
		C: Ordinary classes
MacMahon 1987²⁷	54 children with learning disabilities but normal WISC-R, aged 7.1–12.75 years	I: Distance running, aerobic dance, and soccer, HR >160	25 min, 5 times a week for 20 weeks
		C: Maze patterns, dodge ball, volleyball, HR <150
MacMahon 1988¹⁵	98 boys from juvenile detention facilities, aged 14–18 years	I: Long distance running and vigorous basketball, HR >160	40 min, 3 times a week for 3 months
		C: Less vigorous activity; baseball, volleyball, etc, HR <160
Marsh 1988²⁸	137 girls, aged 11–14 years	I: Aerobics, competitive with individual training	35 min, 14 times during 6 weeks
		C: Social volleyball game
Munson 1988³¹	26 offenders from a security institution, mean age 17.2 years	I: Strength training, frisbee, golf, volleyball, basketball, etc	1 hour a week for 10 weeks
		C: Discussions
Percy 1981³²	30 healthy fifth and sixth grade pupils	I: Running	1 mile, 3 times a week for 7 weeks
		C: No intervention	Decided when to run themselves
Salokun 1994³⁴	288 healthy young people, aged 12–18 years	I: Field hockey (96), sprint (32), discus (32), or long jump (32)	45 min, 3 times a week for 10 weeks
		C: No skill training
Smith 1984³⁶	32 healthy pupils, fourth and fifth grade	I: Progressive running	10 weeks
		C: Ordinary PE class
Tuckman 1986³⁷	154 healthy pupils, fourth to sixth grades	I: Running	30 min, 3 times a week for 12 weeks
		C: Ordinary PE class