The authors have declared that no competing interests exist.
Conceived and designed the experiments: AT JAS ARS WC EMS LF. Performed the experiments: JAS. Analyzed the data: AT JAS ARS. Wrote the paper: AT.
Personality traits and cardiorespiratory fitness in older adults are reliable predictors of health and longevity. We examined the association between personality traits and energy expenditure at rest (basal metabolic rate) and during normal and maximal sustained walking. Personality traits and oxygen (VO2) consumption were assessed in 642 participants from the Baltimore Longitudinal Study of Aging. Results indicate that personality traits were mostly unrelated to resting metabolic rate and energy expenditure at normal walking pace. However, those who scored lower on neuroticism (r = −0.12) and higher on extraversion (r = 0.11), openness (r = 0.13), and conscientiousness (r = 0.09) had significantly higher energy expenditure at peak walking pace. In addition to greater aerobic capacity, individuals with a more resilient personality profile walked faster and were more efficient in that they required less energy per meter walked. The associations between personality and energy expenditure were not moderated by age or sex, but were in part explained by the proportion of fat mass. In conclusion, differences in personality may matter the most during more challenging activities that require cardiorespiratory fitness. These findings suggest potential pathways that link personality to health outcomes, such as obesity and longevity.
Physical fitness and personality traits are related to lifestyles that promote health
Energy expenditure at rest, or resting metabolic rate, reflects the energy required for basal physiological functioning. Energy expenditure during normal-paced walking provides an index of energy required for normal activity, and energy expenditure during peak sustained walking provides an estimate of aerobic capacity that is highly correlated with maximum energetic capacity (VO2 max)
The Institutional Review Board of the Medstar Research Institute approved the protocol and each participant signed an informed consent form. All clinical investigation has been conducted according to the principles expressed in the Declaration of Helsinki.
Participants were part of the Baltimore Longitudinal Study of Aging (BLSA), an ongoing multidisciplinary study of aging implemented by the National Institute on Aging. Concurrent measures of energy expenditure and personality traits were available for up to 642 participants (48% women) with age ranging from 31 to 96 (
Personality traits were assessed with the Revised NEO Personality Inventory (NEO-PI-R), a comprehensive measure of the Five Factor Model of personality
Energy expenditure (the volume of oxygen consumed) was assessed at rest and at normal and maximal sustained walking speed using a Cosmed k4b2 portable metabolic analyzer (Cosmed, Rome, Italy). Prior to testing, the Cosmed was calibrated using a 3.0 liter flow syringe and gases of known concentrations. Oxygen consumption and carbon dioxide production were continuously collected and analyzed with breath-by-breath measurement, and averaged over thirty second intervals to reduce variability. Energy expenditure was calculated as the average volume of oxygen consumed per kilogram of body weight (VO2 ml/kg/min) for each test.
Resting energy expenditure was assessed for 16 minutes in the morning after an overnight stay in a quiet thermo-neutral environment, in a fasted state. To ensure a stable rate of oxygen consumption and reduce variability, the first 5 minutes of values were removed and the average energy expenditure from minutes 5.5–15.5 was used in the analysis.
Normal and maximal-sustained walking energy expenditure were assessed during the “long-distance corridor walk” (LDCW), a two-part validated measure of cardiorespiratory fitness
Height and weight were assessed by clinical staff using standard methods. A dual-energy X-ray absorptiometry scan was used to assess the proportion of fat and lean tissue. Cigarette smoking was assessed with questions on current and former smoking status.
Partial correlations were used to examine the association between personality traits and energy expenditure measured at rest, normal pace, and peak sustained walking. All analyses controlled for age and sex to account for age and sex differences in both energy expenditure and personality traits
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Age, mean (SD), years | 67.01 (12.86) |
Female, No. (%) | 310 (48.30) |
BMI, mean (SD), Kg/m2 | 27.37 (4.97) |
Fat free mass, mean (SD), Kg | 48.30 (10.17) |
Fat mass, mean (SD), Kg | 27.57 (10.74) |
Distance at normal walking, mean (SD), m | 186.46 (28.75) |
Time for 400-m walking corridor, mean (SD), min | 4.45 (0.96) |
Energy expenditure (VO2 ml/kg/min) | |
Rest, mean (SD), ml/kg/min | 2.64 (0.61) |
Normal walking pace, mean (SD), ml/kg/min | 12.29 (2.55) |
Fast walking pace, mean (SD), ml/kg/min | 17.67 (4.78) |
Note. N = 642 for fast walking pace on the 400-m walking corridor, N = 634 for normal walking, N = 441 for rest data.
Rest | Normal walking | Fast walking | |||
VO2 | Distance | VO2 | Time | VO2 | |
Age | -.14** | -.41** | -.05 | .55** | -39** |
Sex | -.11* | -.08 | -.14** | .14** | -.19** |
Height | .10* | .22** | .14** | -.30** | .27** |
Neuroticism | .00 | -.08 | -.02 | .14** | -.12** |
Extraversion | -.01 | .08* | .05 | -.13** | .11** |
Openness | .04 | .08* | .09* | -.13** | .13** |
Agreeableness | -.07 | -.02 | -.05 | -.03 | -.01 |
Conscientiousness | .00 | .09* | .03 | -.09* | .09* |
N1: Anxiety | -.06 | -.05 | -.01 | .09* | -.08* |
N2: Angry Hostility | .08 | -.01 | .03 | .11** | -.07 |
N3: Depression | -.01 | -.09* | -.01 | .14** | -.10* |
N4: Self-consciousness | -.06 | -.04 | -.04 | .05 | -.08* |
N5: Impulsiveness | .07 | -.08* | -.01 | .11** | -.10* |
N6: Vulnerability | -.02 | -.07 | -.03 | .10* | -.10* |
E1: Warmth | -.06 | .06 | .01 | -.07 | .05 |
E2: Gregariousness | -.04 | .01 | -.04 | -.04 | .00 |
E3: Assertiveness | .04 | .08 | .08* | -.08* | .10* |
E4: Activity | .06 | .20** | .18** | -.24** | .21** |
E5: Excitement-Seeking | .00 | -.05 | -.04 | .00 | .02 |
E6: Positive Emotions | -.05 | .07 | .05 | -.13** | .08* |
O1: Fantasy | .01 | .04 | .03 | -.03 | .04 |
O2: Aesthetics | .03 | .05 | .05 | -.04 | .03 |
O3: Feelings | .06 | .03 | .05 | -.05 | .09* |
O4: Actions | -.01 | .11** | .09* | -.16** | .13** |
O5: Ideas | -.02 | .03 | .07 | -.08 | .12** |
O6: Values | .09 | .07 | .07 | -.17** | .14** |
A1: Trust | -.03 | .07 | .07 | -.09* | .11** |
A2: Straightforwardness | -.06 | -.02 | -.04 | -.02 | .01 |
A3: Altruism | -.04 | .03 | .00 | -.09* | .04 |
A4: Compliance | -.10* | -.08* | -.08* | .00 | -.01 |
A5: Modesty | -.06 | -.02 | -.07 | .05 | -.10* |
A6: Tender-mindedness | .01 | -.04 | -.07 | .03 | -.09* |
C1: Competence | -.03 | .05 | .00 | -.04 | .02 |
C2: Order | .01 | .06 | .03 | -.07 | .05 |
C3: Dutifulness | .02 | .06 | .04 | -.09* | .11** |
C4: Achievement Striving | .06 | .09* | .07 | -.09* | .13** |
C5: Self-Discipline | .03 | .10* | .05 | -.11** | .06 |
C6: Deliberation | -.08 | .04 | -.05 | -.01 | .02 |
Note. N = 642 for peak walking speed on the 400-m walking corridor, N = 634 for normal walking, N = 441 for rest data. Covariates: age, sex, and height. * p<0.05; **p<0.01
Personality traits were largely unrelated to resting energy expenditure (
We repeated the analyses accounting for differences in the proportion of lean and fat mass, and found similar results to those reported in
As reported elsewhere
In a sample that spanned from middle adulthood to old age, we found that individuals low in neuroticism and high in extraversion, openness, and conscientiousness demonstrated higher aerobic capacity at maximal sustained walking speed. Personality, however, was mostly unrelated to metabolic rate at rest and during normal walking. These results indicate that personality differences emerge mostly when greater energetic effort is required, with a resilient personality profile associated with higher aerobic capacity. This observation is consistent with evidence linking these same personality traits, particularly low neuroticism and high conscientiousness, to better health and longevity
The associations between personality and aerobic capacity at maximal sustained walking speed could be due to a number of mechanisms. Individuals with a more resilient personality profile (e.g., low neuroticism and high conscientiousness) are more likely to maintain an active lifestyle
In addition to behavioral and physiological mechanisms, personality traits might be linked to peak performance through more “motivational” psychological processes. Some individuals simply do not put as much effort in the task as others; some might push themselves to their limit while others do not. For example, those who score lower on dutifulness are less committed and less likely to strictly adhere to task instructions, and those who score lower on achievement striving are more lackadaisical and less driven
The activity facet of extraversion had the strongest association with walking energy expenditure. Active individuals tend to be energetic, keep busy, and live an active and fast-paced life. Thus, it is not surprising that those who are dispositionally active would have greater aerobic capacity. Individual differences in the level of activity is a temperamental trait that emerges early in life, and activity is perhaps the personality trait that has the steepest decline in old age
We found lower aerobic capacity to be associated with most facets of neuroticism, a domain strongly associated with risk of depression and other mental health conditions
The strong associations between aerobic capacity and the openness domain were relatively unexpected, although some evidence are consistent with such association
Of the five domains of personality, we found no association with agreeableness. This is somewhat surprising given that antagonistic individuals are likely to engage in health risk behaviors, such as cigarette smoking
The associations between personality traits and energy expenditure did not vary by age or by sex. Both resting and maximal energy expenditure decline with age, albeit at different rates. We found, however, that personality traits shared similar associations with energy expenditure regardless of age. These cross-sectional analyses suggest that the association between personality and energy expenditure does not differ markedly across the middle to latter part of the lifespan. The pattern of associations was also similar for men and women. Most of the associations remained significant even after accounting for body composition parameters and cigarette smoking. Conscientiousness was the exception, with part of this association accounted for by the proportion of lean and fat tissue. Individuals that score low on conscientiousness may have lower aerobic capacity because of the higher proportion of fat tissue. The association between personality, physical fitness and obesity is likely to be complex, with reciprocal influences. Future studies could test to what extent physical fitness mediates the association between personality and obesity. Interestingly, our findings suggest that the personality-obesity association (and similarly the personality links to health and longevity) is more likely to be mediated by peak energetic capacity rather than resting metabolic rate.
Among the limitations of this study is the selective nature of the sample. BLSA participants tend to be more educated and from higher socio-economic status compared to the general population. Given that multiple tests were performed, there is an increased likelihood of false positive results. Before reaching firm conclusions, these findings need to be replicated in independent samples. Another limitation is the cross-sectional nature of the analyses. Only a few participants in our sample had multiple assessments of energy expenditure using the same procedure, but it would be interesting to examine whether personality traits predict the differential rate of decline in aerobic capacity with aging. It is also likely that aerobic capacity and health status influence changes in personality over the lifespan. Lower energy level might be associated with more pronounced changes in personality, with accelerated changes toward the personality profile typical of older adults (e.g., less open, less extroverted)
In conclusion, the reported associations highlight the links between personality traits and cardiorespiratory fitness in older adults, both of which are powerful predictors of disability and mortality. We found a strikingly contrasting pattern, with personality traits related to aerobic capacity at peak walking speed, but unrelated to resting metabolic rate. In addition to the links between personality traits and energy expenditure, this study is informative on the role of psychological traits in lifestyles associated with successful aging.