---Error and correction------
(1)I went to climb (the) Apple Hill (=The Alps?) yesterday.
As I climbed higher, the air became thinner!
(2)I needed to spend much energy (Not power)
on the climb. (Not on climbing the hill....)(No need to repeat word Hill.)
Or go climbing as a sport.
(3)It's an exhausting climb.
It's a three hour's climb to the summit.
Can I climb down?
Hope you're successful.