Table 4. Results of linear mixed effects model with power (log-transformed) as independent variable and age, method (i.e. leg extension, stair ascent, sit-to-stand), sex and body mass as fixed factor, age and test method in interaction and subject as random factor.

Leg extension (for method) and men (for sex) were used as the reference.

Factor	Estimate	SE	p-value
Intercept	6.001	0.095	< 0.001
Age	-0.009	0.001	< 0.001
Method stair ascent	0.200	0.045	< 0.001
Method sit-to-stand	-1.115	0.044	< 0.001
Sex	-0.252	0.034	< 0.001
Body mass	0.011	0.001	< 0.001
Age*Method stair ascent	-0.005	0.002	< 0.001
Age*Method sit-to-stand	0.005	0.002	0.002

SE = standard error,

* refers to an interaction term.