Exercise Adherence
Exercise adherence is the research field's name for whether a person keeps training over weeks, months and years, as distinct from how motivated they felt on the day they started. The best single number available comes from Sandro Sperandei and colleagues, who followed 5,240 members of one medium-sized fitness centre in central Rio de Janeiro and reported that 63 per cent stopped before their third month and that fewer than 4 per cent lasted a continuous year. That study measured cancelled payments rather than attendance, which matters more than the headline, and it is one gym in one city. The determinants are not equal either: identity, how a session feels while it is happening, and self-efficacy are better evidenced than the factors popular fitness writing names instead.
What it is
Adherence is the unglamorous half of exercise science. Almost everything published about training assumes somebody is doing it, and the field that studies whether anybody actually does has spent forty years arriving at an answer that flatters nobody: what predicts continued training is less a personal quality than an arrangement of schedule, context, identity and social architecture around the person.
There is no single originator. The field runs back through Rod Dishman's 1982 review in Health Psychology, through Dishman and Sallis in 1994, and through Robison and Rogers in Sports Medicine in 1994, and its baseline finding is that roughly half of those who start a structured exercise programme drop out within six months, with most of the loss early and most relapse inside the first three months. Dishman and Sallis give that dropout as a band of roughly 10 to 50 per cent over six months depending on programme and population, and it should be quoted as a band. Those are reviews of supervised cohorts, mostly clinical and workplace, not of people who joined a gym.
This vault credited Pedro Teixeira as the originator of the concept until September 2026, which was wrong and has been corrected. Teixeira's contribution is the application of self-determination theory to exercise, not the field itself.
The measurement problem sits underneath every number on this page. Dropout can mean a cancelled membership, an attendance record falling below some threshold, or a person's own report that they stopped. Those three measures give different answers from the same population, and most of the figures that circulate in fitness marketing do not say which one they used.