From the sounds of the trail, an hour and twenty minutes might not be bad for 1.2 miles.

Those 8 inch logs are difficult for me and my left knee. Any other height doesn't bother it. They are for erosion and are generally found on old trails.

You didn't say if your friends went back with you. I'm hoping they did. Even though it would be a disappointment, I wouldn't let anyone go back alone.

I consider hiking on hilly trails to be about twice as hard as walking on the road.

My other suggestion, if you decide to try this again, is for you to lead and have a no passing rule. If the friends want to hike faster, let them fall behind or even start 5 or 10 minutes later. That way you get the full rest break when you take one and you aren't always playing catch up. That's the fastest way to move a group along.

You could also pick a short and a long destination. There could be a campsite a mile or so in, and another farther away. You could even car camp instead of hiking to the campsite.

If you have chronic mild back problems, I suggest getting your cholesterol and blood pressure checked. The lower back is the first place arteriosclerosis starts showing symptoms. The next symptom could be a slipped disk. It's not something you want to deal with.

I just noticed you went back the next day. Trekking poles would help on the logs.