Here at HikingLasVegas.com we hike and rock scramble and there's a big difference. Hiking is walking in the mountains. Rock scrambling is low level climbing normally without ropes. When hiking you rarely, if ever, use your hands. You are constantly using your hands when rock scrambling.
Hiking to mountain peaks above 10,000 feet is a great cardio workout. Rock scrambling is a great full body workout. They are two different types of physical activities. Hiking one mile and rock scrambling one mile are totally different. I have written that a mile of rock scrambling is easily as difficult as hiking two miles, though it's hard to compare.
Las Vegas offers both hiking and rock scrambling. Of course you can hike anywhere, but the best cardio hiking is in Mt. Charleston due to the elevation. Red Rock Canyon offers some of the best rock scrambling in the country.
We have you covered. If you prefer hiking, the web site has over 150 hikes in southern Nevada and beyond. If rock scrambling is your thing, we are the best source in the world with many scrambles not found anywhere else (books or web sites).