Table 2 Correlation between physiological (ie, blood lactate concentration and HR) values and variables describing the characteristics of the game

	All games (n = 76)		Service games (n = 38)		Return games (n = 38)
	r	p Value	r	p Value	r	p Value
Heart rate
SR	0.38	0.001	0.34	0.035	0.19	0.261
RD	0.23	0.047	0.32	0.049	0.17	0.298
CD	0.25	0.027	0.31	0.055	0.16	0.345
Blood lactate
SR	0.43	<0.001	0.49	0.002	0.43	0.009
RD	0.51	<0.001	0.40	0.002	0.45	0.006
CD	0.40	<0.001	0.44	0.006	0.41	0.013

SR, strokes per rally; RD, rally duration; CD, changes of direction.