Table 1.

Cohort information and experimental conditions

	Untrained Rest	Untrained Exercise	Trained Rest
	(UR)	(UE)	(TR)
n	22	17	22
Male	8	8	8
Female	16	9	16
Mean age in days (Range)	590 (513–673)	765 (649–896)	947.6 (884–1051)
Exercise parameters (WD1):
-Mean Peak Velocity (m/s)	.	16.2 (14–17.1)	.
-Mean Peak Heart Rate (bpm)	.	224 (212–233)	.
-Mean Peak Plasma Lactate (mmol/l)	.	26.7 (20.8–32.2)	.
Mean sub-maximal training weeks prior to sampling (canter)	0	4.7 (1.6–13.1)	27.7 (10.1–47.0)
Mean work days prior to sampling:	0	1	15.1 (6–43)
n = 0	22
n = 1	0	17	0
n > 1	0	0	22
> 5 n ≤ 11	0	0	8
> 10 n ≤ 20	0	0	9
n > 20	0	0	5

Number of individuals (n), males and females, and mean age are given for experimental cohorts Untrained Rest (UR), Untrained Exercise (UE) and Trained Rest (TR). Details of exercise and training regimens for each Thoroughbred cohort prior to sampling day are also shown. Sampling of the Untrained Exercise (UE) cohort was performed ~4 h post-exercise on the first work day (WD1). Sampling of the Trained Rest (TR) cohort was performed after an average of ~15 WDs over a six-month training period