You're running a 10k, 1/2 Marathon or Marathon maybe you went out too fast, or it just doesn't seem to be your day. Each mile is a struggle and you're slowing down despite trying to get your tempo back. Would it ever be in your best interest to walk for a brief period (30 seconds or so) and reset your body so to speak? Almost like the last half of your race is a new interval?
Marathon, yes. Other races, no. (unless a run/walk beginner)
I once ran a 5k XC race that went similar to what you described. The course started out flat for 1.3 miles or so and then got into some insane hills that were probably past 45 degrees in some places. I ran a strong first mile, in the top 30 runners or so, but then I went over a few of those hills and they crushed me. It seemed like every step there was more fire in my quads, and I ended up walking for a few seconds multiple times.
I finished with a 21:58, about halfway through the 170-man field. My first mile probably had me on pace for a 20:30 or so. That was the last race of last XC season. I am in much better shape now and my track season has been going well (one win, one second place finish) so far, but I still feel awful about it.
Short answer: Don't walk. You will regret it. Like, a lot.
I can well remember "running" in the later stages of the national-championship marathon. A guy who was alternating walking with running (you know, like the old "scout pace": maybe 50 steps of walking and a couple hundred of running) came up, passed me, and disappeared into the distance.
The idea is to get to the finish line as fast as you can, not to be able to say "I ran the whole thing!" For a lot of people it's probably faster to run (a true running speed, say 7-8min/mi) and walk, rather than a continuous slog-and-jog. You'll also hurt less, the next couple of days.
Leadville, maybe.
I won a marathon in which I walked... I was leading by like 1200 meters and at mile 24, started getting bad quad cramps. Tried messing with my form but they eventually seized my legs and I had to stop. So pissed. Tried to massage out the cramps. Walked by a water station (so lucky) and chugged like 6 cups of water. Knew the guy behind me would be coming soon so I started jogging again. Cramps never came back and I ended up finishing with a decent time. Walking seemed to work for me in that scenario, although I did not break 2:30 and likely would have had I not stopped to walk.
Imo, unless you're doing a marathon, ultra, or racing with intense elevation change, no. Unless you're injured or feel like you will injure yourself by continuing running, then to walk is to quit.
Never because they are RUNNING races! I've had to walk in a couple of races and they are my worst disappointments.
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