The 4:1 Rule - Why You Can’t Bank Time in a Marathon

The Temptation

Every marathon runner feels it - the buzz on the start line, fresh legs after the taper, the crowd pushing you forward, the supporters cheering you one - you feel a million dollars, I’ve nailed this marathon malarky as you look at your watch and think, “I feel great, I’m on for a pb, I’ll run a little quicker now and bank some time.”

It’s the biggest mistake in marathon running EVER!

The Rule

For every 1 second per mile you run too fast in the first 10k, you’ll give back around 4 seconds per mile in the final 10k.

• Goal pace = 10:00/mi.

• You start at 9:45/mi (15 seconds too fast).

• By the end, you’ll likely fade to around 11:00/mi or slower.

That’s not banking time, it’s borrowing time, with very painful interest and it’s not pretty!

Why It Happens

Running too fast early on:

• Burns through glycogen stores quicker.

• Pushes you closer to your lactate threshold too soon.

• Breaks down your running economy leading to fatigue, poor form, and heavy legs.

By mile 20, the maths always wins,

The Smarter Way

• Start 10–15 seconds slower than goal pace for the first 2–3 miles.

• Settle into your target pace by mile 5.

• Hold it steady through the middle.

• Save your energy for the final 10k, when discipline pays off.

Conclusion

The marathon isn’t about bravado in the first 10k, it’s about control, patience, and letting your training carry you to the finish, remember, nobody sees the first mile but they always see the last!