Table 1. Baseline characteristics of participants.
Variable Full sample (n = 180) Lower-performance internal reference group (n = 60) Middle tertile (n = 60) Higher-performance group (n = 60) Sig.
Age, years 23.9 ± 4.0 23.8 ± 3.9 23.9 ± 4.0 24.0 ± 4.1 0.787
Male sex, n (%) 112 (62.2) 37 (61.7) 38 (63.3) 37 (61.7) 0.986
Taekwondo, n (%) 64 (35.6) 21 (35.0) 22 (36.7) 21 (35.0) 0.992
Sanda, n (%) 61 (33.9) 20 (33.3) 21 (35.0) 20 (33.3) 0.992
Brazilian jiu-jitsu, n (%) 55 (30.6) 19 (31.7) 17 (28.3) 19 (31.7) 0.992
Height, cm 173.6 ± 7.3 173.2 ± 7.4 173.7 ± 7.4 174.0 ± 7.1 0.548
Body mass, kg 70.8 ± 8.7 70.4 ± 8.8 70.8 ± 8.8 71.2 ± 8.5 0.614
Body mass index, kg/m2 23.5 ± 2.1 23.4 ± 2.2 23.5 ± 2.0 23.6 ± 2.1 0.602
Body fat, % 15.8 ± 3.3 16.8 ± 3.5 15.7 ± 3.2 14.9 ± 2.8 0.001
Skeletal muscle mass, kg 35.8 ± 4.2 34.7 ± 4.4 35.6 ± 4.0 37.1 ± 4.0 0.002
Resting heart rate, bpm 63.4 ± 6.0 65.2 ± 6.2 63.4 ± 5.8 61.7 ± 5.4 0.001
Systolic blood pressure, mmHg 117.1 ± 8.2 118.0 ± 8.5 117.2 ± 8.1 116.2 ± 7.9 0.232
Diastolic blood pressure, mmHg 74.6 ± 6.2 76.4 ± 6.5 74.6 ± 6.0 72.9 ± 5.9 0.003
RMSSD, ms 53.6 ± 12.9 48.2 ± 12.4 54.8 ± 12.3 57.8 ± 12.0 < 0.001
Training age, years 7.9 ± 2.5 6.8 ± 2.3 8.1 ± 2.4 8.9 ± 2.6 < 0.001
Weekly training sessions, n 5.5 ± 1.3 4.8 ± 1.2 5.5 ± 1.1 6.2 ± 1.4 < 0.001
Weekly training load, hours 9.7 ± 3.4 7.9 ± 3.0 9.8 ± 3.1 11.4 ± 3.6 < 0.001