A	Age	yr
a	Slope of a linear relationship	W/(kg·yr)
Ab	Body surface area	m2
b	Intercept of a linear relationship	W/kg
BMI	Body mass index	kg/m2
CV	Coefficient of variation	–
Hb	Height of the subject	cm
HR0	Heart rate at rest	bpm
HR90	HR value exceeded during 90% of the duration of the HR recording	bpm
HR99	HR value exceeded during 99% of the duration of the HR recording	bpm
HRM	HR value in case of purely dynamic efforts	bpm
HRmax	Maximum heart rate	bpm
HRwm	Average heart rate at work during the observation period	bpm
M0	Metabolic rate at rest	W or W/m2
Mb or BMR	Basal metabolic rate	W or W/m2
Meq	Equivalent metabolic rate	W
MWC	Maximum working capacity	W
R	Correlation coefficient	–
RMR	Resting metabolic rate	W or W/m2
SD	Standard deviation	–
SDHRmax	Standard deviation of HRmax	bpm
SDMo	Standard deviation of M0	W or W/m2
SDMWC	Standard deviation of MWC	W or W/m2
SDWb	Standard deviation of Wb	kg
t1, t2, t3, t4	Radom values in a Gauss normal distribution
VO2max	Maximum oxygen consumption	l/min
Wb	Body mass	kg
Wbid	Ideal body mass	kg
Wbid,m	Ideal body mass of men	kg
Wbid,w	Ideal body mass of women	kg
ΔHRM	HR increase due to the dynamic muscular load, under neutral thermal conditions	bpm
ΔHRN	HR increase associated to mental effects	bpm
ΔHRS	HR increase due to static muscular work	bpm
ΔHRTh	HR increase associated with the increase in core temperature	bpm
ΔHRε	residual component of the instantaneous heart rate	bpm
Θ	Sum of the components of heart rate other than from dynamic muscular load	bpm