What We Talk About When We Talk About Exercise (Part 1)

December 31 2025

It was an afternoon class during my undergraduate studies in sports science at the University of Malaya. After his opening remarks, the late Dr. Mohamed Nor Che’ Noh posed three seemingly simple questions: What is physical activity? What is exercise? What is sport? And how do they differ?

More than 100 of us sat there – most have been physically active for years, many have been exercising most days of the week, some of us are competing at national or international levels in various sports. Yet none of us can give a correct, let alone precise, answer.

As a physical educator in training, Dr. Mohamed Nor considered it paramount to carefully define the concepts of “physical activity”, “exercise”, and “sport”. These terms are not interchangeable, and their fundamental distinctions matter for meaningful discussions in any health-related scientific inquiry. It was in his lecture that I first learned how carelessly we use these words, and how much clarity we lose in the process.

The framework of Carl J. Caspersen and his colleagues in 1985 provides the foundation for decades of progress in epidemiology, public health, and exercise science. Physical activity is “any bodily movement produced by skeletal muscles that results in energy expenditure” above a basal level. It is the broadest category, encompassing everything from fidgeting at your desk to running a marathon. The amount of energy required varies continuously from low to high and correlates positively with physical fitness. Therefore, we should not mistake physical activity for exercise, which is a subcategory of it.

xercise is narrower – a subset of physical activity that is “planned, structured, repetitive, and performed specifically to maintain or improve one or more components of physical fitness.” When we exercise, we intentionally exert ourselves to sustain or enhance our health and fitness, as exercise correlates significantly with physical fitness. The key distinction is purpose-driven: exercise has a fitness goal. Therefore, not all physical activity is exercise.

Sport narrows further still. It is a subset of exercise conducted within defined rules toward specific goals, whether for recreational or competitive purposes. Sports involve physical activity with motor skills, carried out individually or in teams, and are supported by institutional frameworks such as leagues, federations, and governing bodies. Competition, whether against others or against personal benchmarks, becomes central.

The next question is, how do sport and exercise differ from physical activity?

Consider how one activity – cycling – can occupy all three categories depending on context and intent.

In countries like the Netherlands and China, cycling is a mode of transportation – people pedalling to school, work, or markets. They are physically active, burning calories and moving their bodies, but they are not exercising. Their goal is to travel from point A to point B, not to improve fitness. The health benefits of the activity are incidental, not intentional.

In Malaysia, cycling has surged in popularity as a weekend activity over the past decade. Enthusiasts plan riding routes, track distance cycled, and monitor their performance (i.e., cycling speed). When the weather does not allow outdoor rides, these weekend warriors take indoor spinning classes or roller workouts once or twice a week to maintain their cardiovascular fitness and cycling power. Here, cycling becomes exercise – structured sessions with explicit fitness goals. The activity is planned and purposeful.

Professional cyclists training for Olympic gold represent sport. Their cycling involves competition, institutional support, rigorous rules, and performance objectives that transcend mere fitness. They have coaches, follow periodized training programs, compete under international regulations, and pursue medals and rankings. The same physical activity now exists within an entirely different framework.

The same pedalling motion occupies three distinct categories depending on context and intent.

Today, after eight years of teaching the postgraduate course in clinical exercise science, I very often open my first lecture of each academic year with Dr. Mohamed Nor’s questions. Only a few students with backgrounds in exercise and sport science provide satisfactory answers. The confusion persists because we casually conflate these terms in everyday conversation, and the consequences extend beyond semantics.

Why does the distinction matter? Because confusing them creates barriers to effective intervention and health promotion strategies. When public health guidelines recommend “150 minutes of physical activity weekly,” they are actually prescribing exercise – structured, purposeful movement at moderate to vigorous intensity. When someone says they are “active” because they stroll from one shopping mall to another or garden in their backyard on weekends, they are describing physical activity, which may or may not meet exercise recommendations. When we discuss declining sports participation among youth, we are measuring something different still – organized, rule-based, regulated competitive activities.

These fundamental distinctions shape how we design interventions, allocate resources, and set personal goals. A workplace wellness program promoting “more physical activity” differs fundamentally from one providing structured exercise classes. Understanding what we are actually discussing allows for more transparent communication between exercise professionals and the public.

Dr. Mohamed Nor taught us that precision in language reflects precision in thinking. When we talk about exercise, we need to know exactly what we are talking about and what we are not. Twenty-seven years later, that lesson endures, as relevant in clinical practice as it was in that undergraduate classroom.