Running Economy: Why Two Runners With the Same VO₂max Race Differently

Running economy is the oxygen cost of running at a given submaximal speed. It is measured in millilitres of oxygen per kilogram per kilometre, and lower is better: the economical runner is the one who needs less oxygen to hold the same pace, leaving more headroom before their ceiling.

Its importance became clear when researchers began finding elite runners whose laboratory VO₂max values were unremarkable and whose race results were not. Frank Shorter won an Olympic marathon with a VO₂max well below several of his contemporaries. The difference was not the size of the engine but the efficiency with which it was used.

The three-variable model

Distance running performance is well described by three physiological quantities working together.

Maximal oxygen uptake sets the absolute ceiling on aerobic energy production. It is highly heritable, improves perhaps fifteen to twenty percent with training in an untrained person, and then plateaus stubbornly.

Lactate threshold determines what fraction of that ceiling you can sustain. This responds well to training and is the variable that most distinguishes trained from untrained runners at the same VO₂max.

Running economy determines how much oxygen a given speed demands. It continues improving over years of training, long after VO₂max has stopped moving, which is why runners in their thirties with a decade of training behind them keep getting faster despite a static ceiling.

The VDOT model is useful precisely because it collapses all three into one performance-derived number, sidestepping the problem of measuring them separately.

What actually improves it

Heavy resistance training

The most consistently supported intervention in the literature, and the one most distance runners neglect. Two sessions a week of heavy, low-repetition strength work — squats, deadlifts, calf work at loads above eighty percent of maximum — improves economy by figures often reported in the two to eight percent range, with no meaningful gain in body mass. The mechanism is neuromuscular and elastic rather than hypertrophic: stiffer musculotendinous units return more energy per stride.

Plyometrics

Jumping, bounding and hopping improve stretch-shortening cycle function, which is the mechanism by which the Achilles tendon and plantar fascia store and return elastic energy at each contact. Six to eight weeks of twice-weekly plyometric work produces measurable economy gains in trained runners. Start conservatively; the tissue loading is high.

Volume, accumulated over years

The least glamorous and possibly the most powerful factor. Running economy improves with cumulative training history in a way that appears to keep going for a decade or more. Part of this is tendon adaptation, part is refinement of motor patterns, part is body composition. There is no shortcut available.

Mass, in the right places

Oxygen cost scales with the mass being transported, and mass at the extremity of the limb costs disproportionately more because it must be accelerated and decelerated through a large arc. This is the honest argument for lighter shoes, and it is a real effect — roughly one percent of economy per 100 grams per shoe. It is not an argument for weight loss at any cost; running economy improves nothing if the athlete is underfuelled, and low energy availability degrades bone, endocrine and immune function long before it improves race times.

What does not help as much as advertised

Deliberate gait retraining towards some idealised form is the biggest disappointment in this area. Self-selected stride mechanics are usually close to individually optimal, and imposed changes typically make economy worse in the short term and only sometimes recover. The exception is genuine overstriding, discussed in more detail in the piece on cadence.

Forefoot versus rearfoot striking shows no consistent economy advantage either way in the research. Runners converted from one to the other generally get slower before they get back to where they started, if they get back at all.

Shoes, and the honest version

Carbon-plated racing shoes with high-resilience foam midsoles produce measurable economy improvements, commonly reported around four percent versus traditional racing flats, with substantial individual variation. Some runners get almost nothing. The effect is real and it is also not evenly distributed, which is why the honest advice is to test rather than assume.

The relevant caution is that the economy gain does not come with an equivalent gain in tissue tolerance. Runners who put high-stack plated shoes into daily training sometimes find new problems, particularly around the foot and calf, because the shoe alters loading patterns the tissue has not adapted to.

A practical programme

If you are already running consistently and want to improve economy specifically: add two heavy strength sessions a week in the base phase, keep them away from quality running days, and include short hill sprints of eight to ten seconds twice weekly. Give it twelve weeks before judging. Economy moves slowly and unglamorously, which is why so few runners pursue it and why those who do keep improving after everyone else has plateaued.