Table 2.

Associations between significant characteristics after bi-variate analysis and race time for the master half-marathoners, master marathoners and 100-km master ultra-marathoners using multiple linear regression analysis

Group		β	SE	P Value
Half-marathoners(n=103)	Age	0.3	0.2	0.1
	Skeletal muscle mass	-0.2	0.4	0.7
	Percentage of body fat	0.9	0.3	0.008
	Weekly running hours	0.1	1.1	0.9
	Weekly running kilometres	-0.3	0.1	0.01
	Speed in running training	-4.5	1.0	< 0.0001
Marathoners(n=91)	Age	0.6	0.3	0.06
	Skeletal muscle mass	1.2	0.8	0.1
	Percentage of body fat	2.2	0.7	0.004
	Weekly running hours	-0.5	1.8	0.8
	Weekly running kilometres	-0.05	0.2	0.7
	Speed in running training	-11.6	1.9	< 0.0001
100-km ultra-marathoners(n=155)	Age	6.4	1.2	< 0.0001
	Skeletal muscle mass	6.2	2.3	0.008
	Percentage of body fat	7.6	1.9	0.0001
	Weekly running hours	-2.1	1.9	0.3
	Weekly running kilometres	-4.8	3.9	0.2
	Speed in running training	-1.5	0.3	< 0.0001

β = regression coefficient; SE = standard error of the regression coefficient. The coefficient of determination (r ²) of the model was 0.47 for master half-marathoners, 0.55 for master marathoners, and 0.47 for master ultra-marathoners, respectively