Table 3.

Adolescent Long Distance Runners' Characteristics by Sport Specialization Level and Sex

Variables  Sport Specialization Level	Mean ± SD		P Value
	Males	Females	Sport Specialization Level	Sex
Age, y
Low	15.9 ± 1.0	15.6 ± 1.4	.96	.01e
Moderate	15.7 ± 1.0	15.7 ± 1.2
High	16.1 ± 0.9	15.4 ± 1.0
Health score
Low	83.2 ± 15.3	85.6 ± 9.7	.07	.52
Moderate	84.4 ± 11.6	83.9 ± 12.5
High	89.8 ± 7.9	86.0 ± 10.2
Pittsburgh Sleep Quality Index score
Low	4.8 ± 2.3	5.2 ± 2.7	.19	.02e
Moderate	4.2 ± 2.3	5.4 ± 2.6
High	4.0 ± 2.1	4.6 ± 3.1
Sleep duration, h
Low	7.9 ± 1.5	7.8 ± 1.2	.11	.24
Moderate	7.6 ± 1.2	7.4 ± 1.5
High	7.9 ± 1.1	7.7 ± 1.0
Weekly running distance, km
Low	18.9 ± 21.1	21.1 ± 19.1	<.001d	.04e
Moderate	35.2 ± 20.8a	29.0 ± 21.9a
High	58.3 ± 22.6b,c	45.8 ± 30.9bc
Average running distance, km/run
Low	5.2 ± 5.3	5.3 ± 4.1	<.001d	.01e
Moderate	7.4 ± 3.4	6.0 ± 3.6
High	10.2 ± 2.8b,c	7.7 ± 5.1b,c
Running enjoyment score
Low	77.8 ± 25.1	77.9 ± 17.4	<.001d	.58
Moderate	86.2 ± 14.8a	85.0 ± 14.0a
High	90.2 ± 9.2b	88.5 ± 10.1b

^aDifference between moderate- and low-level specialized runners.

^bDifference between high- and low-level specialized runners.

^cDifference between high- and moderate-level specialized runners.

^dDifference among sport specialization levels.

^eDifference between sexes.