Zac Efron: Shirtless Hiking Hunk

A solo Zac Efron goes shirtless as he takes a hike on a Hollywood Hills mountain trail in Los Angeles on Tuesday (February 10).

The 21-year-old actor kept his hair from flopping around by wearing a headband and kept hydrated with a bottle of Fiji water.

To coincide with the release of his upcoming film 17 Again, Zac is rumored to be the host of Saturday Night Live on April 11. No word on who the musical guest for the evening will be yet. 17 Again is set to open on Friday, April 17.

20+ pictures inside of shirtless hiking hunk Zac Efron…