What the research says about actually sticking with the gym

Every line below is quoted word for word from the linked source. We picked the passages and wrote the headings; the sources did the talking.

How habits actually form

The average time it took for the participants in my study to form a daily habit was 66 days.

— University of Surrey, Does it really take 66 days to form a habit? We asked the expert, Dr Pippa Lally

However, the range was 18 to 254 days. Therefore, what we really showed was that how long habit formation takes is highly variable.

— University of Surrey, Does it really take 66 days to form a habit? We asked the expert, Dr Pippa Lally

Four studies reported the median or mean times to reach habit formation, ranging from 59–66 days (median) and 106–154 days (means), with substantial individual variability (4–335 days).

— PMC, Time to Form a Habit: A Systematic Review and Meta-Analysis of Health Behaviour Habit Formation and Its Determinants

When behaviors are repeated in a consistent context, there is an incremental increase in the link between the context and the action. This increases the automaticity of the behavior in that context.

— Wikipedia, Habit

A narrative review by Gardner (2015) showed that the predictive effect of intention on health behavior weakens when habit strength increases.

— Frontiers in Psychology, A Systematic Review Examining the Relationship Between Habit and Physical Activity Behavior in Longitudinal Studies

The present meta-analysis provides support for the use of implementation intentions to promote physical activity, even though the effect size is small to medium.

— McMaster Optimal Aging Portal, A meta-analytic review of the effect of implementation intentions on physical activity

Same time every day

In a study of 375 adults who have successfully maintained weight loss and who engage in moderate-to-vigorous intensity physical activity, most reported consistency in the time of day that they exercised, with early morning being the most common time. The Obesity study also found that being consistent in the timing of physical activity was associated with higher physical activity levels, regardless of whether people exercised consistently during the morning, afternoon, or evening.

— ScienceDaily, Timing of exercise may be key to successful weight loss

A consistent exercise time may both help to establish a cue for exercise, thus facilitating habit formation, and protect time for exercise, thus simplifying planning and reducing perceived lack of time as a barrier. Additionally, consistent early morning exercise was related to greater stability in exercise routine and the strongest exercise habits.

— PMC, Consistent exercise timing as a strategy to increase physical activity: A feasibility study

Enjoyment over discipline

The strongest predictor for reporting regular exercise attendance was higher levels of the motive ‘enjoyment’ (OR = 1.84, p ≤ 0.001), followed by self-efficacy ‘sticking to it’ (OR = 1.73, p = 0.002) and social support from friends and family (OR = 1.16, p ≤ 0.001).

— PMC, What Makes Individuals Stick to Their Exercise Regime? A One-Year Follow-Up Study Among Novice Exercisers in a Fitness Club Setting

There is consensus in the literature that access to exercise facilities (environmental factors), enjoyment (intrinsic motives), and fulfillment of goals positively influence exercise adherence, whereas lack of time, social support, and energy (internal barriers) inhibit exercise adherence.

— PMC, Motives and barriers to initiation and sustained exercise adherence in a fitness club setting: A one-year follow-up study

Temptation bundling

Participants were randomly assigned to a full treatment condition with gym-only access to tempting audio novels, an intermediate treatment involving encouragement to restrict audiobook enjoyment to the gym, or a control condition. Initially, full and intermediate treatment participants visited the gym 51% and 29% more frequently, respectively, than control participants, but treatment effects declined over time (particularly following Thanksgiving).

— NBER, An Evaluation of Temptation Bundling

After the study, 61% of participants opted to pay to have gym-only access to iPods containing tempting audiobooks, suggesting demand for this commitment device.

— NBER, An Evaluation of Temptation Bundling

Partners, support, and coaching

This well-studied motivation-gain effect occurs in team tasks when the less capable partner of a team exhibits greater motivation in terms of effort, relative to individual performance, when performing as part of a team on effort-based tasks. LDP participants (M = 235.37) persisted 28.9 seconds longer than those in the IC (M = 206.47), resulting in a 14% increase.

— PMC, Introductory Dialogue and the Köhler Effect in Software-Generated Workout Partners

Individuals who receive regular exercise coaching are more likely to adhere to their exercise routine, compared with those who exercise individually. All intervention arms exercised more frequently than controls (mean difference: 1.1-1.5; P≤.001), with no differences in weekly exercise frequency between the 3 intervention arms (P=.30).

— PMC, Impact of In-Person and Mobile Exercise Coaching on Psychosocial Factors Affecting Exercise Adherence in Inactive Women With Obesity

Adherence (number of sessions completed, expressed as a % of sessions prescribed) to supervised training averaged 72% ± 24% over 12 months and dropped to 43% ± 40% during the six months of unsupervised training. Though older survivors cite a preference for home-based training, women may have lost motivation to train as often due to the loss of social support and instructor attention.

— PMC, A randomized-controlled trial comparing supervised aerobic training to resistance training followed by unsupervised exercise

Distance from the gym

It turns out that people who only travelled 3.7 miles or less to their gym went five or more times a month, while those who had to travel five miles or more only went once a month.

— Coach, Here’s how close your gym needs to be to ensure you go regularly

Tracking and self-monitoring

Researchers from the University of South Australia reviewed almost 400 studies involving 164,000 people across the world using wearable activity trackers. Wearable activity trackers encourage us to walk up to 40 minutes more each day (approximately 1800 more steps). They encourage people to exercise on a regular basis, to make it part of their routine and to set goals to lose weight.

— ScienceDaily, Wearable activity trackers encourage us to walk up to 40 minutes more each day

Money, commitment, and rewards

Can incentives be effective in encouraging the development of good habits? We investigate the post-intervention effects of paying people to attend a gym a number of times during one month. In two studies we find marked attendance increases after the intervention relative to attendance changes for the respective control groups. This is entirely driven by people who did not previously attend the gym on a regular basis.

— IDEAS/RePEc, Incentives to Exercise (Econometrica)

Consistent with existing findings, workers responded strongly to an incentive targeting use of the company gym, but long‐run effects were modest, at best. However, workers in the treatment arm that combined the incentive program with a commitment contract option showed long‐lasting behavioral changes, persisting even 1 year after the incentive ended.

— NBER, Incentives, Commitments and Habit Formation in Exercise: Evidence from a Field Experiment with Workers at a Fortune-500 Company

We show that 45% of these interventions significantly increased weekly gym visits by 9% to 27%; the top-performing intervention offered microrewards for returning to the gym after a missed workout. Only 8% of interventions induced behaviour change that was significant and measurable after the four-week intervention.

— IDEAS/RePEc, Megastudies improve the impact of applied behavioural science (Nature)

Unused memberships and dropout

First, members who choose a contract with a flat monthly fee of over $70 attend on average 4.3 times per month. They pay a price per expected visit of more than $17, even though they could pay $10 per visit using a 10-visit pass. On average, these users forgo savings of $600 during their membership.

— IDEAS/RePEc, Paying Not to Go to the Gym (American Economic Review)

Of those classified as non‐regular exercisers (63.0%), exercise dropout was reported by 38.8%, 48.3%, and 56.0% at 3, 6, and 12 months, respectively.

— PMC, Motives and barriers to initiation and sustained exercise adherence in a fitness club setting: A one-year follow-up study

Fresh starts and the January cliff

Visits to the gym increased drastically at the start of a new semester, as well as the beginning of a new week, month, year and after a student celebrated a birthday.

— Knowledge at Wharton, Need a Fresh Start? Here’s How to Begin

That resolve starts to waver in the third week in January, data shows. Check-ins on Facebook to facilities with ‘gym’ or ‘fitness’ in the name drop 10% in February, according to two years of Facebook data.

— Fox News, New Year’s resolutions to exercise waver toward late January, data show