Table 1.

Mean and standard deviation of the spatiotemporal variables and scales during running in four conditions: free and Nordic running in regular terrain (FR and NR), and free and Nordic running in irregular terrain (FI and NI)

Variable	FR	NR	FI	NI	Mode	Terrain	Mode*Terrain
Speed (m/s)	3.37 (0.40)	3.32 (0.27)	3.40 (0.35)	3.51 (0.49)	0.66	0.33	0.22
Stride length (m)	2.47 (0.25)	2.54 (0.18)	2.54 (0.29)	2.66 (0.36)	0.11	0.24	0.60
Stride time (s)	0.74 (0.04)	0.77 (0.04)	0.75 (0.04)	0.77 (0.05)	< 0.001	0.45	0.09
Contact phase (%)	32.4 (2.4)	32.4 (3.2)	32.0 (3.1)	31.6 (2.9)	0.68	0.14	0.52
Aerial phase (%)	67.6 (2.4)	67.6 (3.2)	68.0 (3.1)	68.4 (2.9)	0.69	0.14	0.54
RPE (0–10)	1.4 (0.1)	1.7 (0.9)	1.8 (0.8)	2.0 (0.8)	0.02	0.07	0.28
Feeling (− 5 to + 5)	+ 4.0 (1.3)	+ 3.8 (1.3)	+ 3.1 (0.4)	+ 3.0 (0.6)	0.34	0.01	0.90

The p values are presented for the comparisons between conditions for the factor mode of running (free and Nordic running), terrain (regular and irregular), and their interaction (mode*terrain). The statistically significant values of p are bolded. The significance level used was α = 0.05. RPE rating of perceived exertion