Table 2 Correlations between total number of headings and biomarker levels in the whole group of soccer players (n = 23)*.

Variables	Sample correlation coefficient	95% CI	p Value
Albumin ratio	0.37	−0.047 to 0.68	0.080
T‐tau	−0.004	−0.42 to 0.41	0.98
GFAP	−0.19	−0.56 to 0.24	0.38
S‐100B in CSF	−0.019	−0.43 to 0.40	0.93
S‐100B in serum	−0.35	−0.67 to 0.069	0.099

CSF, cerebrospinal fluid; GFAP, glial fibrillary acidic protein; T‐tau, total tau.

*No correlation for neurofilament light protein (NF‐L) is presented since the NF‐L concentration was <125 ng/l in all samples.