Table 2. Overview of all features.

Category	#	Features
Descriptive	2	Gender (0 = male, 1 = female)	G
		Body mass (kg)	BM
Heart rate	8	Average	${\text{HR}}_i^{(-1)}$
Acceleration	480	Average	${\text{HR}}_{l,d,i}^{(-1)}$
		Standard deviation	${\text{SD}}_{l,d,i}^{(-1)}$
		Variance	${\text{VAR}}_{l,d,i}^{(-1)}$
		Root mean square	${\text{RMS}}_{l,d,i}^{(-1)}$
		Power	${\mathrm{P}}_{l,d,i}^{(-1)}$

Notation: stage number i = 0, 1, 2, 3 (stage 0 is the warm-up stage); accelerometer location l = t, bl, bu (t = left or right tibia, bl = lower back, bu = upper back); direction d = x, y, z, total (x = anterior-posterior, y = mediolateral, z = vertical); the superscript (−1) means that both the feature and its inverse are computed.