How to Run Faster: The Training That Actually Works

By Cristian Serb · Updated September 9, 2026

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To run faster, train the four things that set your speed: your aerobic base from easy mileage, your VO2 max from hard intervals, your lactate threshold from tempo runs, and your running economy from strides and strength. Most runners improve fastest by adding easy volume plus one or two interval sessions a week, not by running every run harder.

The most common way runners try to get faster, running every run at a moderately hard pace, is also the least effective. Speed comes from developing four separate physiological levers, each with its own kind of session. This guide covers what each lever is and exactly how to train it.

What Actually Makes You Faster

Your sustainable running speed rests on three physiological limits plus one efficiency factor:

• VO2 max, the maximum amount of oxygen your body can use. It sets the ceiling on your aerobic power. A higher VO2 max means a faster pace is still aerobic.
• Lactate threshold, the fraction of that ceiling you can hold for a long time. Two runners with the same VO2 max but different thresholds will race very differently.
• Aerobic base, the capillary and mitochondrial machinery that delivers and uses oxygen. It is the foundation the other two are built on, and it is developed by volume.
• Running economy, how much oxygen you burn at a given pace. Better economy means the same speed costs less, so you go faster for the same effort.

Train all four and your pace at every distance improves. Neglect them and hammer the middle instead, and you plateau. Here is the session for each.

1. Build the Aerobic Base With Easy Mileage

The foundation is easy running, and there needs to be a lot of it. Analyses of elite endurance training across sports find a consistent split: about 80 percent of sessions easy, 20 percent hard (Seiler, 2010). The easy majority builds the oxygen-delivery machinery without the fatigue cost of hard running, which is what lets you train often enough to improve at all.

Easy means zone 2, a conversational effort at roughly 60 to 70 percent of your maximum heart rate, where you could speak a full sentence without gasping. Most runners run their easy days too fast, which quietly turns base-building runs into moderate stress that leaves them too tired for the hard sessions that matter. Slow the easy days down and the whole system works better. Find your range with the zone 2 heart rate calculator.

2. Raise the Ceiling With VO2 Max Intervals

Easy volume builds the base; hard intervals raise the ceiling. The best-studied protocol is the Norwegian 4x4: four 4-minute efforts at 90 to 95 percent of maximum heart rate, each followed by 3 minutes of easy recovery. In a controlled trial it raised VO2 max 7.2 percent in eight weeks, significantly more than moderate continuous training (Helgerud et al., 2007). A meta-analysis of interval training confirms the pattern across studies: high-intensity intervals produce large, reliable VO2 max gains (Milanović et al., 2015).

Shorter, faster repeats work too. Sprint interval training and track sessions of 400 to 1000 metre repeats develop the same top-end power with a more neuromuscular flavour. The rule that matters is time spent near your maximum: the more minutes you accumulate close to VO2 max, hard but controlled, the bigger the adaptation. One such session a week is enough to drive progress.

3. Lift Your Threshold With Tempo Runs

VO2 max is the ceiling; your lactate threshold decides how much of it you can use. You raise the threshold by running at it: a sustained "comfortably hard" effort, around 80 to 90 percent of max heart rate, that you could hold for roughly an hour in a race. A classic tempo session is 20 to 40 minutes continuous at that pace, or broken into longer intervals such as three times 10 minutes with short recoveries.

Tempo running is the lever most recreational runners skip, and it pays off directly at race distances from 5K to the marathon, because it moves the pace you can sustain closer to your ceiling.

4. Sharpen Running Economy

The final lever is efficiency: two runners with identical VO2 max can differ substantially in race pace if one burns less oxygen at the same speed. Running economy improves through three things:

• Strides: 6 to 8 relaxed 20-second accelerations to near-top speed after an easy run, twice a week. They refine mechanics and recruitment without meaningful fatigue.
• Strength training: heavy resistance and plyometric work improve economy by making each stride more powerful and elastic, without adding bulk.
• Consistent volume: economy improves slowly with years of running as the body optimises its mechanics, another reason long-term consistency beats short hard blocks.

Putting It Together

A typical week for an improving runner is mostly easy running, one interval session, one tempo run, strides tacked onto two easy days, and at least 48 hours between the hard sessions. The adaptations happen during recovery, so more hard work is not better past this point; it just erodes quality and raises injury risk.

To train the interval and tempo sessions precisely, set your target paces with the running pace calculator, then run them with your target heart rate on screen and wrist. PEAKVO2 guides the intervals on iPhone and Apple Watch, changes phases automatically, and tracks your VO2 max over time so you can watch the ceiling rise.

References

1. Seiler S. What is best practice for training intensity and duration distribution in endurance athletes? Int J Sports Physiol Perform. 2010;5(3):276-291. PubMed
2. Helgerud J, Høydal K, Wang E, et al. Aerobic high-intensity intervals improve VO2max more than moderate training. Med Sci Sports Exerc. 2007;39(4):665-671. PubMed
3. Milanović Z, Sporiš G, Weston M. Effectiveness of high-intensity interval training and continuous endurance training for VO2max improvements: a systematic review and meta-analysis. Sports Med. 2015;45(10):1469-1481. PubMed