Is hiking as effective as running and gym PT?

I did a steep but short hike at about 6k ft every week for a few months and it helped to give me the best pt score I ever received.
Use hiking as a supliment to other forms of exercise. Still keep doing the rest of your work out.

Nothing is a good substitute for running just like nothing is a good substitute for swimming. Running is high impact and stresses your bones and various muscles in a completely different way. Hiking and rucking are great for your health, but won't help you pass the APFT.
Why would you not run because of COVID if you're still able to get outside to hike?

It’s a different workout. Don’t exchange one for the other. Just change it up occasionally.

Also there is a big difference between hiking in the mountains in Colorado and hiking in the woods in California.

Depending on your MOS and mission, I find it more important to carry a ruck than run in shorts.
During COVID19 days, staying out of the gym is a necessity. Running and hiking are great for the combat mission anytime

It’s good PT especially if you carry a heavy pack. You’ll burn a ton of calories and build core strength, hip flexor strength, leg strength etc.

As for cardiovascular fitness you still can’t beat sprint drills to be in shape for that dreaded 2 mile run.

I have hiked for years so ruck marches I can eat them up no problem, but you make me run 3-4 miles like a BTN run and I’m miserable. I’m built for endurance not speed. I believe they call me a Clydesdale.

It drpends on the goal. For purposes of calorie consumption / weight loss, a mile is a mile is a mile, run, jog, or walk.
For purposes of cardiovascular HEALTH it is pretty much the same. For cardiovascular STRENGTH, propably not, unless you are doing some SERIOUS hiking.
Same goes for leg muscle strength and endurance. Hiking can help you maintain most of what you have. But hiking uses different muscles in different combinations and sequences. So you will build up different muscles and different muscle memory. This isn't necessarily a bad thing, but if you use it to completely replace running, your running ability will deteriorate over time.

How about walking instead of hiking. Walking is less impact, especially when you are my age, 67 this month.

I had a permanent profile change in the last four years of my military service because of a leg injury. In the late 1990s, the Air Force allowed you to walk three miles at a PT standard of a little less than a 15 minute mile.

So, these days I'm up at 4:30 in the morning, still wearing my AF PT gear and doing six miles around a high school track or a YMCA track. Had a lot of déjà vu moments seeing the sun come up.

In retirement (now 26 years) this form of exercise is extra important. You see four years ago, I attended a wedding where I ran into an older cousin who was overweight, had smoked, had a massive coronary and a quadruple by-pass with serious complications. Add to that they discovered he had lung cancer in the middle of the surgery and took out half of a lung. His hair was white and his hands shook. He had died on the table and was brought back. Lots of excuses. Lots of drugs.

After seeing him, I reminded my wife that I was retired from the Air Force and it was time to get back with the program. We now both walk. I've lost weight, and we have walked the 5K and 10K events of the Air Force Marathon now going on three years.

There is just something very humbling when you're in a race like that. You're one of thousands, competing with wounded warriors or others with similar challenges, some wearing prosthesis' while others use special wheel chairs. You competing with them toward a common goal. You're in their league. If they can do it, why can't you or me.

Not going back...

Regardless of what you do it all comes down to time and intensity. Running, Hiking, or being in the gym is only as effective as how hard you hit it and for how long. Hiking is a fine way to stay fit. Nothing wrong there but its all about getting a good sweat and putting in the work.

Although hiking can be strenuous and you can create an increased heart rate the breathing is not as increased as with jogging/running. As a 60 year old smoker and disabled I realize how valuable the lungs are. Your breathing will be affected so instead of just hiking do a little rock or creek jumping and jog up the hills..

I say yes. Good leg and cardio workout, depending on the slope and intensity.