Table 3.

PS_nt* for Participants Before and After Exercise Training

Training Status	N	Mean PSnt*	SD
Pretraining	56	0.98	0.7
Young adults	24	1.12	1.0
Older adults	32	0.87	0.32
Men	24	0.75	0.57
Women	31	1.14	0.83
Post-training	40	0.91	1.5
Young adults	14	1.09	0.64
Older adults	26	0.82	1.8
Men	18	0.76	0.63
Women	22	1.04	1.9

Note: PET = positron emission tomography.

*Presynaptic uptake by the norepinephrine transporter-1 function was measured using PET imaging of [¹¹C]-meta-hydroxyephedrine, a norepinephrine analog, and expressed as a permeability–surface area product (PS_nt in mL/min/mL).