The best way of acclimatising and getting fit for adventures further west is to climb the beautiful Mt Jiulian. The trail rises steeply through forest but the top is a rolling grassland plateau of between 3500 and 4000m, beyond which horses and yaks graze and there might even be the odd nomad tent. Access it behind Zhilam Hostel, which can provide maps and guides (advisable) for guests.
If you've just arrived in town from lower elevations, be sure to spend at least one day resting before climbing up.