Table 1.

The value of b determines how a physiological parameter varies with body mass.

b	Significance	Example (value of b)
0	Parameter does not change with body mass	Bone density in mammals, cell radius
1	Parameter changes in direct proportion with body mass	Body volume, cell number
0 < b < 1	Parameter increases at a slower rate than body mass	Metabolic rate (3/4), blood flow rate (3/4), external surface area (2/3), life span (1/4)
>1	Parameter increases at a faster rate than body mass	Bone mass (4/3)
<0	Parameter decreases with body mass	Almost all frequencies or rates, e.g., cardiac frequency, respiratory frequency (−1/4)