Exercise and business performance: what the evidence really shows

Three horizons, three kinds of evidence

It helps to separate what exercise does today, this year and over a career. Each horizon has a different quality of evidence behind it.

• Today: mood and attention after a session. Measured in experiments and diary studies.
• This year: sleep, energy and the ability to absorb a heavy schedule. Measured mostly in surveys and observational data.
• A career: health, fitness and survival. Measured in large cohorts followed for years.

None of these is a revenue figure. A leader who expects one will be disappointed, and one who ignores the three horizons is leaving something real on the table.

The same-day effect starts with mood

Coulson and colleagues studied 201 volunteers at three workplaces with on-site gyms. Two thirds were women, and the average age was 38. Each person compared their own days with exercise against their own days without it.

On exercise days, mood improved from before to after the session. Their ratings of their own work performance were higher, whatever the workload or the type of exercise. The authors found that the improvement in performance was almost entirely linked to the change in mood.

The limits matter. Performance was self-reported. Volunteers chose which days they trained, and nobody was blinded. The study shows an association within the same person on the same day. It does not show that sales, decisions or output improved.

Still, for someone who chairs meetings, mood is not a soft variable. The tone of a leader travels through a room quickly, and a session that lifts it before a difficult afternoon is a reasonable investment.

Attention, memory and processing speed

The umbrella review by Erickson and colleagues, prepared for the US Physical Activity Guidelines in 2018, separated two questions. For single sessions, it rated as strong the evidence that moderate to vigorous activity brings a transient benefit to thinking in the period after exercise. For regular activity, it found moderate evidence from randomised trials of improvements in processing speed, memory and executive function.

An earlier review by Hillman and colleagues in Nature Reviews Neuroscience reached a similar conclusion: aerobic exercise can improve several aspects of cognition and brain function. Much of that evidence comes from children and older adults, so the effect in a fit 45-year-old may be smaller.

How to use the short-term effect before a decision is covered in exercise and decision-making.

What workplace studies find about fitness

Pronk and colleagues surveyed 683 workers in 2004. Those who were more active reported smaller losses in the quality of their work and in overall job performance. Those with higher cardiorespiratory fitness reported smaller losses in the quantity of work done, and less extra effort needed to get it done.

The design was cross-sectional. It cannot tell whether activity improved work, or whether people who cope well at work also find time to train.

Sickness absence is weaker ground still. A 2014 review by Amlani and Munir looked at 37 studies and concluded that the evidence gives only limited support to the idea that physical activity reduces absence, because so many of the studies were of low quality. A claim that training "cuts sick days" by a given percentage has no solid basis.

The cost of inactivity, counted at scale

The World Health Organization states that people who are insufficiently active have a 20% to 30% higher risk of death than people who are sufficiently active. It lists better mental health, cognitive health and sleep among the benefits of regular activity in adults.

When it launched its 2020 guidelines, WHO estimated that physical inactivity costs US$54 billion a year in direct health care worldwide, plus US$14 billion in lost productivity. That is a global, society-level figure, not a number any single company can apply to its own staff.

Mental health weighs more heavily. WHO estimates that depression and anxiety cost 12 billion working days a year, or about US$1 trillion in lost productivity. This is not an effect of exercise. It is context for why mood and resilience are economic questions as well as personal ones. The NHS lists better self-esteem, mood, sleep quality and energy among what physical activity can bring, together with a lower risk of early death of up to 30%.

Fitness as an asset you carry for decades

The strongest numbers concern survival. In the study by Mandsager and colleagues of 122,007 patients who had a treadmill test, the least fit group had an adjusted mortality risk 5.04 times that of the most fit. Smoking, by comparison, carried an adjusted risk of 1.41. The data are observational and come from people referred for testing, so they describe an association.

For someone whose value lies in judgement accumulated over thirty years, staying in post and in good health is the performance that matters most. What VO2 max measures, and how to raise it, is set out in the guide to VO2 max.

Measuring your own starting point

Kenneth Cooper's 12-minute run remains the simplest field test. In his 1968 study of 115 US Air Force men, the distance covered correlated at 0.897 with oxygen uptake measured in the laboratory. The formula that converts distance into VO2 max is the conventional one used with the test; it was validated in young military men, so treat your result as an estimate.

1. Warm up for ten minutes, ending with a few faster strides.
2. Cover as much distance as you can in twelve minutes on a flat track, at an even pace.
3. Enter the distance in the calculator below.
4. Repeat the test every three or four months under the same conditions.

In Dubai, run it in the cool hours or in the winter months, since heat lowers the result. See training in the heat.

The Cooper test is a maximal effort. If you have chest pain, breathlessness out of proportion to effort, dizziness, or known heart, metabolic or kidney disease, see a doctor before attempting it, and stop at once if you feel unwell.

Making the case honestly

If you are deciding whether to fund a company gym or to protect your own training time, the evidence supports a modest set of claims.

• Exercise days are associated with better mood and better self-rated work.
• Single sessions give a short-lived lift to thinking.
• Regular activity is linked with better sleep, cognition and long-term health.

It does not support a promised productivity percentage, a guaranteed fall in sick days, or the idea that fit leaders make better decisions because they are fit. Those claims rest on observational data at best.

Where to start this week

Most people do not need more motivation, they need a format. A realistic floor is described in three 30-minute sessions a week, and protecting sleep, which supports every horizon above, is covered in sleep for executives. When the pressure itself is the obstacle, exercise and stress explains how to adjust rather than stop.

If you would like a coach to plan this around your diary, you can create your space in the Club.