It’s not just the distance, the elevation gain will have a big factor too, just like with cycling.
I’ve had the odd time where I’ve finished my postie shift (where I typically walk approx 6-7 miles per shift) to find a puncture and I’ve forgotten to grab my pump and repair kit on the way out of the house that morning. Instead of walking to the local bike store, I’ve frog-marched the ~4.5 miles (~250 foot climbing) home while pushing the bike in ~1 hour.
As a random one-off going one way, it’s annoying, but there’s no way I’d do that both ways everyday!
How long for you? Pick a random number between approx 60 and 120 minutes each way… I don’t know your route, your fitness levels or your weight! (I suspect under 1000Kg) 😉
ton, if the only physical exercise you do is ~5 miles each way cycle commuting to/from work and that is leaving exhausted and grumpy, my immediate hunch is either…
You aren’t using your easiest gears enough
The easiest gears on your current bike aren’t easy enough
Your fitness levels are worsening to a concerning level that perhaps needs medical advice