A sub-4 mile means averaging just under 60 seconds per 400m for four laps plus a few meters. A sub-5 mile means about 75 seconds per 400m. Getting there takes a large aerobic base, a strong 800 speed reserve so that pace feels controlled, years of consistent training, and a race run with an even rhythm and a manageable third lap.
This guide is part of our running training plans by event series.
What is the pace math for a sub-4 or sub-5 mile?
A mile is about 1,609m, so on a 400m track it is four laps plus about 9 meters.
- Sub-4: about 59.7 seconds per 400m, or 1:59.4 per 800m.
- Sub-5: about 74.6 seconds per 400m, or 2:29 per 800m.
The number that matters most is what that pace costs you. A runner who can run 800m in 1:50 is holding about 92 percent of 800 speed in a 4:00 mile. A runner whose 800 best is 1:56 is much closer to the limit and has little left for the last lap. The same logic applies at 5:00: a woman with a 2:15 800 has far more room than one with a 2:25.
Is the mile an aerobic or a speed event?
Mostly aerobic. In highly trained athletes, the aerobic system supplied over four fifths of the energy in a simulated 1500. That is why sub-4 milers usually have a deep aerobic history. But the remaining anaerobic share is decisive in the final lap, and research on middle distance runners shows that the gap between top sprint speed and the speed at VO2 max (the speed reserve) helps explain who can handle surges and finish fast.
So you need both: an engine that keeps the pace aerobic for as long as possible, and an 800 speed reserve that makes the pace feel relaxed and gives you a kick.
What aerobic base sits behind a fast mile?
More than most people expect. Typical ingredients:
- Consistent easy volume built over years, at a level you can hold for weeks without breaking down. There is no magic number; it depends on your history. See how many miles a week you should run.
- A long run as aerobic support, not the centerpiece.
- Threshold work such as tempo runs or cruise intervals, to raise the pace you can hold aerobically.
- Strides and hill sprints every week, from the first week of base. See hill sprints for distance runners.
Which sessions matter most for the mile?
Training connects mile pace from both sides.
From below (aerobic support):
- Threshold runs or reps, for example 4 to 5 x 6 minutes at threshold effort with short jogs.
- 3K and 5K pace reps, for example 6 x 800m at 3K pace with 2 minutes jog.
- Aerobic intervals: 200s at a quick, controlled effort with short jog rests.
From above (speed support):
- 800-pace reps with long rest, for example 4 to 6 x 200m faster than mile pace with full recovery.
- Short sprints and hill sprints to keep top speed growing.
At race pace:
- Mile-pace reps that grow over weeks, for example 6 to 8 x 400m at goal pace with 2 minutes rest, building toward longer reps or less rest.
- Broken miles, such as 2 x (4 x 400m) at goal pace.
Kick and gear changes:
- 300m reps that start at race pace and accelerate smoothly over the last 100m.
- Reps where the change of pace comes at a random point, so you learn to respond.
Strength work and drills support all of this. Quality strides after a lifting session help the strength carry over into running.
What is a realistic progression?
Fast milers are built over years, not weeks. A realistic path:
- Build the base. Raise volume gradually toward what you can sustain, with strides and hill sprints. See why the 10 percent rule is a guide rather than a law.
- Lower your 800 and your 5K. Your mile will be limited by whichever is weaker. If your 800 is slow, the speed reserve is the bottleneck. If you fade in 3Ks, the aerobic side is.
- Race 1500s and miles often. Racing is a skill. Early season races are for learning.
- Expect steps, not leaps. Most runners chip away a few seconds per season. Training that leaves you healthy enough to train next week beats a single heroic block.
Your profile matters too. A speed-type runner needs more aerobic work in small pieces; an endurance-type runner needs more speed. See speed-type vs endurance-type runners.
How should you taper for a mile?
Cut volume over the last week or two while keeping frequency and short quality. A meta-analysis of tapering found the best performance gains with about a two week taper that reduced volume by roughly 40 to 60 percent while keeping intensity and frequency. For a miler, that means keeping 200s and strides so the legs stay responsive.
How do you race a sub-4 or sub-5 mile?
- Run even. A fast first lap costs more than it buys.
- Keep the third lap honest. It is where most attempts slip. Lap three should feel like work, not a rest before the kick.
- Stay attached. A small gap feels enormous when you are tired. Close it deliberately and sit on the runner in front.
- Use the field. A fast, evenly paced race in a good field can pull you to a breakthrough.
- Have cues ready. Pick two or three: relax the shoulders, drive the arms, next runner.
How your HealthAI coach applies this
Your coach looks at your 800, mile and 5K times to find your current bottleneck, then writes 2-week plans that build it while maintaining everything else. Paces come from your current fitness and are updated as you log runs in the health portal. If your check-ins show poor sleep or heavy soreness, your coach adjusts the next key session instead of forcing it. Plans start at $30 a month; see plans.
Your coach builds this around your training data. Start at HealthAI.coach.
Sources
- Spencer MR et al., Energy system contribution during 200- to 1500-m running in highly trained athletes. Medicine and Science in Sports and Exercise, 2001. doi:10.1097/00005768-200101000-00024
- Sandford GN et al., Maximal Sprint Speed and the Anaerobic Speed Reserve Domain: The Untapped Tools that Differentiate the World's Best Male 800 m Runners. Sports Medicine, 2019. doi:10.1007/s40279-018-1010-5
- Bosquet L et al., Effects of tapering on performance: a meta-analysis. Medicine and Science in Sports and Exercise, 2007. doi:10.1249/mss.0b013e31806010e0