Caffeine supplementation is ergogenic in soccer players independent of cardiorespiratory or neuromuscular fitness levels

Table 3 Heart (HR) and rating of perceived exertion (RPE) for the cardiorespiratory and neuromuscular fitness classifications (mean ± SD)

Classification	Variable	Treatment	Group	Treadmill periods
Classification	Variable	Treatment	Group	1st	2nd	3rd	4th
Cardiorespiratory fitness	HR (b∙min⁻¹)*†	Caffeine	HCF	152.88 ± 10.70	159.02 ± 10.62	157.49 ± 14.53	172.18 ± 6.76
		Caffeine	MCF	159.01 ± 11.86	163.22 ± 11.71	161.13 ± 13.33	173.30 ± 15.42
		Placebo	HCF	150.97 ± 11.99	156.84 ± 11.14	150.88 ± 12.49	160.03 ± 7.24
		Placebo	MCF	151.43 ± 16.59	161.44 ± 12.28	159.50 ± 11.59	163.20 ± 20.05
	RPE*†	Caffeine	HCF	10.00 ± 1.51	11.67 ± 2.28	11.70 ± 2.29	14.67 ± 1.93
		Caffeine	MCF	11.23 ± 0.98	13.03 ± 1.34	13.47 ± 1.57	15.23 ± 1.66
		Placebo	HCF	10.37 ± 1.71	12.33 ± 2.15	12.97 ± 1.58	15.53 ± 1.34
		Placebo	MCF	11.20 ± 1.03	13.30 ± 1.70	14.43 ± 1.49	16.60 ± 1.55
Neuromuscular fitness	HR (b∙min⁻¹)*†	Caffeine	HNF	155.28 ± 13.33	163.76 ± 14.14	159.70 ± 17.36	178.54 ± 10.39
		Caffeine	MNF	156.61 ± 9.86	158.49 ± 6.66	158.91 ± 9.72	168.22 ± 11.73
		Placebo	HNF	155.00 ± 11.25	158.16 ± 12.42	157.70 ± 2.12	167.19 ± 10.40
		Placebo	MNF	147.40 ± 16.15	160.12 ± 11.42	152.69 ± 13.07	156.04 ± 16.82
	RPE*†	Caffeine	HNF	10.53 ± 1.64	11.83 ± 1.96	11.83 ± 2.25	14.30 ± 1.16
		Caffeine	MNF	10.70 ± 1.17	12.87 ± 1.89	13.33 ± 1.77	15.60 ± 2.09
		Placebo	HNF	10.63 ± 1.65	12.27 ± 1.57	13.10 ± 1.56	15.47 ± 1.22
		Placebo	MNF	10.93 ± 1.26	13.37 ± 2.21	14.30 ± 1.64	16.47 ± 1.60

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