Table 2.

Electrocardiographic characteristics of elite endurance and strength athletes and non-elite controls.

	Participants attending a 3-KM run test (N = 1,388)			Participants attending a 2-min push-up test (N = 577)
ECG characteristics	Elite endurance athletes (≤780 s) (N = 233)	Controls (>780 s) (N = 1,155)	P-value	Elite strength athletes (≥54 times) (N = 78)	Controls (<54 times) (N = 499)	P-value
Heart rate (beats/min)	61.93 ± 10.02	66.68 ± 10.58	<0.001	65.37 ± 12.05	66.03 ± 10.62	0.61
P duration (ms)	106.36 ± 11.78	105.90 ± 14.05	0.64	108.35 ± 11.75	105.56 ± 14.57	0.10
PR interval (ms)	156.77 ± 16.56	155.62 ± 18.81	0.38	156.41 ± 16.78	154.71 ± 19.93	0.47
QRS duration (ms)	99.95 ± 11.23	97.90 ± 10.95	0.03	98.62 ± 10.21	97.25 ± 10.02	0.26
QTc interval (ms)	387.02 ± 21.95	388.67 ± 22.81	0.30	392.23 ± 26.56	387.75 ± 21.73	0.10
QRS axis (degree)	71.06 ± 22.00	62.89 ± 31.61	<0.001	64.69 ± 25.05	65.00 ± 28.22	0.92
ECG based LVH (%)	165 [70.8]	633 [54.8]	<0.001	51 [65.4]	293 [58.7]	0.26
ECG based RVH (%)	35 [15.1]	177 [15.3]	0.92	13 [16.7]	81 [16.2]	0.92
Sinus bradycardia (%)	102 [43.8]	295 [25.5]	<0.001	28 [35.9]	137 [27.5]	0.12
Ectopic P rhythm (%)	19 [8.2]	108 [9.4]	0.56	5 [6.4]	55 [11.0]	0.21
Left atrial enlargement (%)	36 [15.5]	199 [17.2]	0.50	11 [14.1]	81 [16.2]	0.63
First degree atrioventricular block (%)	3 [1.3]	25 [2.2]	0.38	2 [2.6]	9 [1.8]	0.64
Left axis deviation (%)	0 [0.0]	18 [1.6]	0.05	2 [2.6]	3 [0.6]	0.08
Right axis deviation (%)	30 [12.9]	123 [10.6]	0.32	5 [6.4]	50 [10.0]	0.31
Complete right bundle branch block (%)	12 [5.1]	42 [3.6]	0.27	2 [2.6]	14 [2.8]	0.90
Incomplete right bundle branch block (%)	23 [9.9]	79 [6.8]	0.10	8 [10.3]	30 [6.0]	0.16
QTc prolongation > 480 ms (%)	1 [0.4]	7 [0.6]	0.74	2 [2.6]	2 [0.4]	0.03
T wave inversion (%)	6 [2.6]	37 [3.2]	0.61	2 [2.6]	15 [3.0]	0.83

Categorical variables are expressed as N [%].

ECG, electrocardiography; LVH, left ventricular hypertrophy; KM, kilometer; RVH, right ventricular hypertrophy.