A genetically informed UK study suggests that personality may shape engagement in moderate and vigorous physical activity, with conscientiousness potentially buffering neuroticism’s effects.

Study: Could individual personality traits affect adherence to exercise as a public health intervention? A causal Mendelian randomization study using United Kingdom longitudinal survey data. Image Credit: GoodIdeas / Shutterstock

In a recent study published in the journal Humanities and Social Sciences Communications, researchers investigated whether neuroticism has a causal effect on exercise.

Regular exercise has multiple health benefits, such as lower risks of hypertension, cancer, diabetes, falls, and mortality, and improved sleep, body fat measures, and mental health. Notwithstanding, many people do not perform recommended levels of exercise. In fact, 31% of adults worldwide are physically inactive, a figure projected to reach 35% by 2030. Evidence suggests that personality traits are associated with physical and mental health behaviors and perceptions.

Neuroticism is a personality trait associated with negative emotions. It can predict multiple physical and mental disorders and comorbidities and has been linked to poor health outcomes, such as cancer, respiratory diseases, and cardiovascular diseases. Nevertheless, exercise may benefit neurotic individuals, as a meta-analysis reported a significant negative association between neuroticism and physical activity, although it did not establish causality.

In some studies, neurotic tendencies moderated by conscientiousness have been linked to healthy behaviors, including regular physical activity. The notion of healthy neuroticism suggests that conscientiousness can offset neuroticism’s negative effects, promoting healthier lifestyle behaviors and choices. Studies also suggest that conscientiousness can positively influence the negative association between physical activity and neuroticism.

About the Study

In the present study, researchers investigated whether neuroticism causally affects exercise. They used data from the United Kingdom Household Longitudinal Study (UKHLS). UKHLS Wave 3 collected data on personality traits using the 15-item Big Five Inventory. The current study focused on two personality traits: neuroticism and conscientiousness. The mean score across three items per trait was used to evaluate each trait.

UKHLS Waves 2 and 5 collected information on sports activity, and Waves 7 and 9 covered questions on general activity, from which five exercise-related variables were created: moderate activity, vigorous activity, sports activity, mild sports, and moderate sports. Control variables included age, sex, region, education, marital status, employment status, race, youngest child’s age, urban residency, equivalized household income, and long-term health conditions.

The study sample was split into those below and above the median conscientiousness score. The team first examined the relationship between neuroticism and exercise using regression models. They performed Mendelian randomization with a continuously updated estimator designed to address potentially weak genetic instruments for causal analyses. The causal local average treatment effect was estimated using 33 single-nucleotide polymorphisms (SNPs) as instrumental variables. SNPs were selected from a literature search and the catalog of genome-wide association studies. These causal analyses were restricted to working-age participants of European descent with genetic data, so the estimates do not necessarily apply to all adults.

Findings

The mean neuroticism score was higher among individuals with a conscientiousness score below the median. Moreover, individuals with a conscientiousness score below the median engaged in less exercise than those with a score above the median. Further, the proportion of subjects who engaged in moderate sports decreased with higher neuroticism scores. Likewise, the proportion of individuals with zero days per week of vigorous activity increased with higher neuroticism scores.

Meanwhile, the visual patterns were less clear among people with moderate activity or mild sports. In regression analyses, neuroticism exhibited a significant negative association with all exercise-related variables. In individuals with above-median conscientiousness scores, neuroticism coefficient estimates were smaller in magnitude, though still significant for all outcomes except moderate activity in the correlated-random-effects model, compared with the full sample. Causal analyses revealed a negative impact of neuroticism on moderate levels of physical activity.

Specifically, a one-unit increase in the neuroticism score was associated with a 9.1 percentage-point decrease in the probability that an individual would engage in at least one moderate sporting activity. Moreover, neuroticism negatively affected sports activity, with a one-unit increase in an individual’s neuroticism score resulting in approximately a 5% decrease in the 0-to-10 self-rated sports-activity index. Similarly, a one-unit increase in the neuroticism score was associated with 0.7 fewer days of vigorous activity per week.

Neuroticism also had a significant negative impact on sports activity and moderate sports among individuals with a below-median conscientiousness score. Specifically, a one-unit increase in the neuroticism score was associated with a 31.6 percentage-point decrease in the probability of engaging in moderate sporting activity. In those with above-median conscientiousness scores, neuroticism estimates were not significantly associated with any exercise-related variable. However, estimates of moderate and vigorous activity in this subgroup were not clearly reported, rendering those findings inconclusive.

Conclusions

In summary, the study corroborated the negative association between neuroticism and exercise and estimated a causal relationship under the assumptions required for Mendelian randomization and instrumental-variable analysis. That is, increased neuroticism was estimated to reduce exercise, an effect that appeared to be moderated by conscientiousness. In the causal analyses, neuroticism did not significantly affect mild sport or moderate activity but was estimated to reduce participation in moderate sport, self-rated sports activity, and vigorous activity. These results suggest that further research should assess whether tailored exercise regimens that account for personality can increase adherence and efficacy.

Journal reference:

• Cherodian, R., Franklin, M., Gschwandtner, A., Hunter, R., Jewell, S. L., & Kambhampati, U. (2026). Could individual personality traits affect adherence to exercise as a public health intervention? A causal Mendelian randomization study using United Kingdom longitudinal survey data. Humanities and Social Sciences Communications. DOI:10.1057/s41599-026-08169-w. https://www.nature.com/articles/s41599-026-08169-w