Why are marathon runners so tactical? Any reasonable reason?

Marathons are a competitive sport. Runners want to finish with both the best time they can manage and ahead of other runners. Long distance running is a juggle managing your energy and reserves while not hurting yourself.

Runners often find that the competition of pacing someone produces an overall pace a little faster than they might have thought possible. Pacing the person directly behind you keeps him or her behind you. As the runner in front you might find that you can maintain your position at a slightly easier pace, that is with less injury. Even if the final time is only a second difference you are still ahead in the field (you know, 233rd instead of 234th out of 500). Pacing a person in front of you keeps him or her in catching distance either at the end or at another key point like a water stop.

Drafting is when one runner is literally tailing the runner directly in front of him or her. There is a benefit to drafting, but just like in cycling, constant drafting is both poor sportsmanship and dangerous.

Despite running being a solitary sport, it's still a competitive sport. Your body has a little more energy with the motivation of a competitor.

• One would almost never know who are more prepared while running a marathon as opposed to many other physical sports.

• The time is long and almost anything can happen to anyone. Therefore, almost nobody is there to "pose".

• Usually we would section it into 4-8 parts, every 5km and every 10km.

• The first 5 to 10km is to get ahead of the crowd.

• The first two 10km sections are usually to get it done (following the group leader(s) - in whatever group one would be running).

• The third 10km is a bit difficult to get ready for the final 10km.

• Everything is in the final 5km and 10km, and I'd say 5km.

There is a good point in this answer about injuries.

I just suspect it would be better if they ignored others and focused their attention on their own pace so that they could finish in the shortest possible time.

• That has been done before while practicing.

• Every marathon is different, weather (temperature, humidity), roads, participants and the list goes on.