Table 1. Serum levels of myostatin, follistatin, sclerostin, DKK-1, P1NP, CTX, and cathepsin K on the day before the start of the race as well as within 15 minutes after finishing the race; median [quartiles].

	Before startn = 19	After finishn = 19	P value
Myostatin (ng/ml)	23.73 [21.16; 28.28]	26.73 [21.22; 31.68]	p = 0.0364
Follistatin (pg/ml)	300.8 [236.4; 831.5]	1211 [849.1; 2174]	p = 0.0002
Sclerostin (pmol/l)	29.15 [21.22; 43.51]	27.75 [24.77; 51.66]	n.s.
Dkk-1 (pmol/l)	38.68 [18.76; 48.07]	38.14 [12.73; 46.07]	p = 0.0364
P1NP (ng/ml)	54.37 [38.69; 67.17]	41.14 [26.27; 47.31]	p = 0.0004
CTX (ng/ml)	0.299 [0.216; 0.425]	0.542 [0.309; 0.767]	p = 0.0024
Cathepsin K (pmol/l)	1.8 [0.69; 4.23]	1.4 [0.16; 6.69]	n.s.