Physical activity changes during an automated online weight loss program.

Evidence-based online behavioral weight loss (BWL) treatment targets a combination of diet, physical activity, and behavioral skills training. While weight loss outcomes are well documented, little is known about changes in physical activity. This study examined changes in objectively measured physical activity across the energy expenditure spectrum during a fully automated, online BWL program. Adults with overweight or obesity (n = 63) completed a 12-week, online BWL program. Participants wore an accelerometer for 7 days and body weight was measured in-clinic at pre- and post-treatment. At post-treatment, mean daily moderate-to-vigorous physical activity increased by about 4 min (SE = 1.59, p = 0.01). There were no statistically significant changes in light physical activity or time spent sedentary (p's > 0.05). Despite only minimal changes in moderate-to-vigorous physical activity overall, larger increases correlated with greater weight loss (r = - 0.28, p = 0.02), which averaged 6.1% of baseline weight at post-treatment. Though achieving important weight loss outcomes, online programs may fail to produce clinically relevant improvements in physical activity, which can put weight loss maintenance at risk.

IDENTIFICATION AND RETROSPECTIVE EVALUATION OF A FILARIOID NEMATODE SPECIES IN MANAGED GRASSHOPPER SPARROWS (AMMODRAMUS SAVANNARUM).

The grasshopper sparrow (Ammodramus savannarum) is a species of ground-dwelling passerine bird with 12 different subspecies. The Florida subspecies (Ammodramus savannarum floridanus) is classified as federally endangered, with the most common threats including habitat loss, nest predation, and floods. A managed breeding program was established at White Oak Conservation (Yulee, FL) in 2015 with eastern grasshopper sparrows (Ammodramus savannarum pratensis) as a model for breeding Florida grasshopper sparrows as part of an assurance colony. A filarioid parasite species (Aproctella sp.) was characterized by PCR after identification by blood films and postmortem examinations of both subspecies housed at White Oak Conservation. This Aproctella species was distinct from others with available sequence. Records from 157 eastern and Florida grasshopper sparrows were reviewed, and correlations between presence of filariasis and subspecies, sex, body condition score, and presence of systemic isosporosis, squamous metaplasia, coelomitis, airsacculitis, or a combination of conditions were investigated. Twenty-nine (18.5%) birds (13 of 71 Florida grasshopper sparrows; 16 of 86 eastern grasshopper sparrows) were positive for filariasis by blood film review, grossly or by tissue imprint at postmortem examination, or histologically. Filariasis was significantly correlated with systemic isosporosis, coelomitis, and airsacculitis; was not correlated with subspecies, sex, or squamous metaplasia; and had a questionable correlation with body condition score. This report provides evidence that this Aproctella species has potential to contribute to morbidity and mortality in the grasshopper sparrow. This information will be helpful for implementing effective measures against suspected vectors and for the development of best practice strategies for the health management of the species in breeding programs.

ASSESSMENT OF CAPILLARY ZONE ELECTROPHORESIS AND SERUM AMYLOID A QUANTITATION IN CLINICALLY NORMAL AND ABNORMAL SOUTHERN WHITE RHINOCEROS (CERATOTHERIUM SIMUM SIMUM) AND SOUTHERN BLACK RHINOCEROS (DICEROS BICORNIS MINOR).

Capillary zone electrophoresis (CZE) and an immunoassay for serum amyloid A (SAA) were used to examine serum samples from clinically normal and abnormal southern white rhinoceros (Ceratotherium simum simum) and southern black rhinoceros (Diceros bicornis minor) under managed care. CZE resolved seven fractions as well as subfractions for α1 globulins. Reference intervals were calculated for white rhinoceros (n = 33) and found to have some differences over previously reported intervals generated using agarose gel electrophoresis (AGE) methods in sera from free-ranging animals. In addition, the coefficient of variation related to fraction quantitation was found to be overlapping or superior to that reported for AGE. No significant differences were observed in CZE measurands and total protein between clinically normal and abnormal rhinoceros. In contrast to CZE, significant differences in SAA levels (P < 0.001) were observed in samples from the white rhinoceros between clinically normal and abnormal animals. In addition, in limited sample sets with repeated measures, SAA provided prognostic value. Future studies should generate more robust reference intervals and delineate the application of both SAA quantitation and CZE in routine health assessments and in prognostication.

Successful use of carbon dioxide laser surgery as an adjunctive treatment for feline herpesvirus-1 dermatitis in two cheetahs (Acinonyx jubatus).

Carbon dioxide (CO2 ) lasers are used for a variety of soft tissue procedures. This report describes their use in dermatitis associated with feline herpesvirus-1 (FHV) in two cheetahs. To the best of the authors' knowledge, this is the first report describing CO2 laser use to adjunctively treat FHV-associated skin lesions.

Les lasers au dioxyde de carbone (CO2) sont utilisés pour une variété de procédures sur les tissus mous. Ce rapport décrit leur utilisation dans la dermatite associée à l'herpèsvirus félin-1 (FHV) chez deux guépards. À la connaissance des auteurs, il s'agit du premier article décrivant l'utilisation du laser CO2 pour traiter de manière complémentaire les lésions cutanées associées au FHV.

Los láseres de dióxido de carbono (CO2 ) se utilizan para una variedad de procedimientos de tejidos blandos. Este informe describe su uso en la dermatitis asociada con el herpesvirus felino-1 (FHV) en dos guepardos. A entender de los autores, este es el primer informe que describe el uso del láser de CO2 para tratar de forma complementaria las lesiones cutáneas asociadas con infección con FHV.

Lasers de dióxido de carbono (CO2 ) são utilizados em uma grande variedade de procedimentos de tecidos moles. Este relato descreve a sua utilização na dermatite associada ao herpesvírus felino (HVF)-1 em duas chitas. De acordo com o conhecimento dos autores, este é o primeiro relato descrevendo a utilização do laser de CO2 no tratamento adjunto de lesões cutâneas associadas o HVF.

Affective response to physical activity as a deep phenotype in a non-randomized pilot study.

Large-scale genomic studies are beginning to identify genetic predictors of physical activity (PA). For those genetically predisposed to engage in low PA, a behavioral intervention may target a malleable factor that mediates genetic predisposition to low PA (i.e., intermediate phenotype) to mitigate the genetic influences. In a non-randomized exercise promotion pilot study, we test the feasibility of examining affective response to PA (how one feels during PA) as an intermediate phenotype between genetic variation and PA adherence. We hypothesized that three single nucleotide polymorphisms (SNPs; rs8044769 and rs3751812 in FTO; rs6265 in BDNF), identified from a prior systematic review, would be predictive of affective response to PA, and that affective response to PA would mediate the SNP-PA link. Forty five healthy, low-active adults received a 12-week print-based PA promotion program. Baseline affective response to PA was assessed using the Feeling Scale, a single-item measure of affective valence. Moderate to vigorous PA (MVPA) was assessed using accelerometers pre- and post-intervention. We examined the three SNPs in a weighted genetic score. Age, sex, body mass index, race, and neighborhood walkability were potential covariates. Affective response to PA and MVPA at follow-up (minutes/day over 4-7 days) were regressed on variation in SNPs, controlling for covariates. One unit increase in genetic score was associated with a 0.14 higher mean Feeling Scale, though was not statistically significant (p = 0.13). Among individual SNPs, having an additional FTO rs8044769 C allele was associated with a mean Feeling Scale score of 0.53 units higher (p = 0.015), which was statistically significant after applying the corrected p-value of 0.016. The genetic score or individual SNPs were not predictive of MVPA 12 weeks later, thereby mediation analyses were not performed. The preliminary findings demonstrate the promise of the intermediate phenotype approach.

Daily Instrumental and Affective Attitudes About Exercise: An Ecological Momentary Assessment Study.

BACKGROUND: Daily decisions to exercise may be influenced by day-to-day changes in affective attitudes (AA) and instrumental attitudes (IA) toward exercise. However, the within-day association between AA, IA, and exercise behavior has received little attention. PURPOSE: To examine the effects of more temporally proximal (daily) AA and IA on daily exercise behavior beyond traditionally assessed distal (at the beginning of an exercise program) AA and IA. METHODS: In the context of a 3-month exercise promotion program (N = 50), distal AA and IA were assessed at baseline. Ecological momentary assessment was used to assess proximal AA, IA, and exercise each day. RESULTS: Between-subject differences in distal AA (OR = 1.28, p = .03) and distal IA (OR = 1.34, p = .01) were predictive of average likelihood of exercise each day over the 3-month period. Within-subject differences in proximal AA (OR = 1.19, p = .007), but not proximal IA (OR = 1.11, p = .18), predicted exercise each day beyond the between-subjects effects of distal AA and IA. Exploratory analysis revealed an interaction, such that the within-subjects impact of proximal AA on daily exercise was most evident among individuals who held more negative distal AA at baseline (OR = 0.80, p < .0001). CONCLUSIONS: Attitude type (affective versus instrumental) and temporality (distal versus proximal) are important to consider in attempts to predict and understand exercise behavior. In addition to targeting change in distal attitudes, exercise interventions should target changes in daily AA to impact exercise later in the same day.

A Systematic Review and Meta-analysis of the Outcome Expectancy Construct in Physical Activity Research.

BACKGROUND: Cognition-based theories dominate physical activity (PA) research, and many include a construct broadly defined as "beliefs about the consequences of behavior" (e.g., outcome expectancies, perceived benefits) hereafter referred to as perceived consequences. PURPOSE: With the quantity of available research on this topic, it is important to examine whether the literature supports perceived consequences as a predictor of PA. METHODS: A meta-analysis examining longitudinal associations between perceived consequences and PA in adults was conducted. Studies were eligible if (a) perceived consequences were measured at a time point prior to PA, and (b) the target behavior was a form of PA. An omnibus meta-analysis estimating the mean effect of all included studies, and separate meta-analyses for perceived consequences content categories were conducted. RESULTS: This search yielded 6,979 articles, of these, 110 studies met inclusion criteria. Studies were published between 1989 and 2020, with sample sizes ranging from 16 to 2,824. All studies were evaluated as moderate to high quality. A small positive bivariate association was identified (r = 0.11; 95% CI [0.09, 0.13]) between perceived consequences and PA. Significant associations were identified for time, health, self-evaluative, psychological, and affective consequences. There was no association between perceived weight-related consequences and PA. CONCLUSIONS: The findings emphasize the variability with which existing studies have examined perceived consequences in the PA literature. Future research might examine whether these are important distinctions for understanding PA. Overall, the results suggest utility in examining perceived consequences as a predictor of PA, but constructs with more robust associations may require priority.

Full Viral Genome Sequencing and Phylogenomic Analysis of Feline Herpesvirus Type 1 (FHV-1) in Cheetahs (Acinonyx jubatus).

Feline herpesvirus type 1 (FHV-1) is endemic in captive cheetahs and sporadically causes devastating disease. Modified live vaccines (MLV), intended for use in domestic cats, are used in some captive cheetah populations and have been anecdotally linked to disease in certain subpopulations. Ten FHV-1 isolates from ten captive cheetahs and one isolate from an MLV used to inoculate four of the host animals were analyzed. Viral DNA was extracted for full-genome sequencing by Illumina MiSeq with viral genomes then used for phylogenomic and recombinational analyses. The FHV-1 shed by vaccinated cheetahs were almost identical to the MLV, with few variants among viral genomes. Eight cheetah FHV-1 isolates and the MLV were grouped in a clade along with FHV-1 isolates from domestic cats in the USA. The remaining two cheetah FHV-1 isolates (unknown host vaccine status) were not associated with a clade. The likely ancestral origin of these two isolates involves recombination events between Australian domestic cat and cheetah FHV-1 isolates. Collectively, these data suggest that the MLV is capable of causing clinical disease and viral shedding in some cheetahs and represents evidence of interspecies transmission of virus between domestic and wild cats.

Exercise as a smoking cessation treatment for women: a randomized controlled trial.

Cigarette smoking remains the leading behavioral risk factor for chronic disease and premature mortality. This RCT tested the efficacy of moderate intensity aerobic exercise as an adjunctive smoking cessation treatment among women. Participants (N = 105; age = 42.5, SD = 11.2) received brief smoking cessation counseling and 10 weeks of nicotine replacement therapy and were randomized to 12 weeks of moderate intensity exercise (Exercise; n = 53) or 12 weeks of health education (Control; n = 52). Longitudinal models, with Generalized Estimating Equations, showed no differences between Exercise and Control in cotinine-verified 7-day point prevalence abstinence (Wald = 1.96, p = 0.10) or continuous abstinence (Wald = 1.45, p = 0.23) at 12-weeks (post-treatment) or 6-, 9-, or 12-month follow-up, controlling for differences in baseline nicotine dependence. There was no effect of exercise on smoking cessation. The present study adds to the literature suggesting null effects of exercise as a smoking cessation adjunctive treatment despite promising findings in short-term laboratory based studies.

EVALUATION OF A VISUAL ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA) FOR PREGNANCY DETECTION IN FOUR UNGULATE SPECIES.

This study evaluated the use of a commercially available, visual enzyme-linked immunosorbent assay (ELISA) for diagnosis of pregnancy in okapi (Okapia johnstoni), gerenuk (Litocranius walleri), eastern giant eland (Tragelaphus derbianus spp. gigas), and dama gazelle (Nanger dama). This assay has been validated for use in domestic cattle, sheep, goats, and water buffalo. Unlike other blood-based pregnancy associated glycoprotein (PAG) detection methods, this assay does not require sophisticated laboratory equipment for detection or interpretation and can therefore be utilized in many settings. Banked serum samples from gerenuk (n = 11), giant eland (n = 4), dama gazelle (n = 33) and okapi (n = 3) were tested, and a pregnant and nonpregnant sample from each individual were included. The ELISA showed 100% sensitivity and specificity in gerenuk and giant eland samples, and 0% sensitivity in dama gazelle and okapi samples. Using this assay, pregnancy was detected by 7-8 wk gestation in gerenuk and 6 wk in giant eland. These results are consistent with previous studies that were able to accurately detect pregnancy in other members of the family Bovidae, but it is possible that PAGs present in okapi and dama gazelle are structurally dissimilar relative to the intended test target, and are therefore unrecognizable using this test. The faint positivity in the dama gazelle assays may be due to cross-reactivity with other proteins in the sample, or due to inconsistent binding with the dama gazelle PAG. This ELISA appears to be an accurate, rapid, and inexpensive method of point-of-care pregnancy diagnosis in gerenuk and giant eland, but not okapi and dama gazelle. Additional studies should be pursued to further characterize the limits of pregnancy detection using this assay in gerenuk and giant eland, and to investigate the validity of this test in other nondomestic ruminant species.

Affective response to physical activity as an intermediate phenotype.

Over the past seventy years, biomedical and epidemiological research has shown that regular physical activity (PA) is critical for physical and mental health. Despite this knowledge, physical inactivity is the fourth leading risk factor for global mortality, accounting for 9% (5.3 million) of premature deaths annually. We suggest this mismatch between knowing about the risks of PA and engaging in regular PA can be reconciled by focusing less on expected health benefits of PA and more on how people feel during PA. Specifically, in this position paper, we argue that affective response (feeling good versus bad) to PA is an intermediate phenotype that can explain significant variance in PA behavior and is, in turn, a function of genetic variability. In making this argument, we first review empirical evidence showing that affective response to PA predicts future physical activity behavior. Second, we systematically review research on single nucleotide morphisms (SNPs) that are associated with affective response to PA. Investigating affective response to PA as an intermediate phenotype will allow future researchers to move beyond asking "What SNPs are associated with PA?", and begin asking "How do these SNPs influence PA?", thus ultimately optimizing the translation of knowledge gained from genomic data to intervention development.

Evaluation of intervention components to maximize outcomes of behavioral obesity treatment delivered online: A factorial experiment following the multiphase optimization strategy framework.

BACKGROUND: Behavioral lifestyle intervention (BLI) is recommended as a first-line treatment for obesity. While BLI has been adapted for online delivery to improve potential for dissemination while reducing costs and barriers to access, weight losses are typically inferior to gold standard treatment delivered in-person. It is therefore important to refine and optimize online BLI in order to improve the proportion of individuals who achieve a minimum clinically significant weight loss and mean weight loss. STUDY DESIGN: Five experimental intervention components will be tested as adjuncts to an established 12-month online BLI: virtual reality for BLI skills training, interactive video feedback, tailored intervention to promote physical activity, skills for dysregulated eating, and social support combined with friendly competition. Following the Multiphase Optimization Strategy (MOST) framework, the components will first be refined and finalized during Preparation Phase pilot testing and then evaluated in a factorial experiment with 384 adults with overweight or obesity. A priori optimization criteria that balance efficacy and efficiency will be used to create a finalized treatment package that produces the best weight loss outcomes with the fewest intervention components. Mediation analysis will be conducted to test hypothesized mechanisms of action and a moderator analysis will be conducted to understand for whom and under what circumstances the interventions are effective. CONCLUSION: This study will provide important information about intervention strategies that are useful for improving outcomes of online BLI. The finalized treatment package will be suitable for testing in a future randomized trial in the MOST Evaluation Phase.

Age Moderates the Effect of Self-Paced Exercise on Exercise Adherence among Overweight Adults.

Objective: The present study tested the hypothesis that the effect of self-paced exercise on adherence to exercise programs is more pronounced with increasing age. Method: Fifty-nine low-active overweight adults (18-65 years) were encouraged to walk 30 to 60 min/day and randomized to either self-paced (n = 30) or prescribed moderate-intensity (n = 29) conditions. Results: The effect of study condition was moderated by age (main effect: b = 6.14, SE = 2.54, p = .02; Condition × Age: b = -11.55, SE = 3.77, p < .01), such that among participants >50 years, those in the self-paced condition exercised 6 more min/day than participants in the prescribed moderate-intensity condition (p = .02), whereas among participants <50 years, those in the self-paced condition exercised 5.4 fewer min/day compared with those in the moderate-intensity condition (p = .05). Affective response to physical activity did not mediate the moderating effect of age. Discussion: As age increases, adults may be more likely to adhere to self-paced versus prescribed moderate-intensity exercise.

Affective response as a mediator of the association between the physical and social environment and physical activity behavior.

Perceptions of the physical and social environment have been shown to be predictive of physical activity (PA) behavior. However, the mechanisms of this association have not been examined. Affective response to PA was examined as a putative mediator of the association between perceptions of the PA environment and subsequent PA behavior. As part of a PA promotion study, 59 low-active overweight or obese but otherwise healthy adults completed real-time assessments of the perceived physical and social PA environment, affective response to PA, and PA behavior over a 6-month period. As hypothesized, decreased latency to and greater duration of subsequent PA was predicted by engaging in PA with a partner (b = 17.24, SE = .45, p < .01), engaging in PA outdoors versus indoors (b = 3.70, SE = 0.67, p < .01), and perceived pleasantness of the physical (b = 0.59, SE = .17, p < .01) and social settings (b = 0.68, SE = .16, p < .01). Affective response to PA (a shift toward feeling good versus bad during PA) mediated the association between engaging in PA with a partner (a path: 0.53(.11), p < .01, b path: 0.42(.12), p < .01, ab path: 0.22(.08), 95% CI .09-.41) and perceived pleasantness of the physical (a path: .38(.02), p < .01; b path: .65(.23), p = .01; ab path: .25(.09), 95% CI .08-.43) and social setting (a path: .35(.02), p < .01; b path: .57(.23), p = .01; ab path: .20(.08), 95% CI .03-.37) and PA behavior, but not the association between engaging in PA outdoors versus indoors and PA behavior. These findings suggest that perceived environmental variables may have their effects on PA through the process of psychological hedonism.

Small sustainable monetary donation-based incentives to promote physical activity: A randomized controlled trial.

OBJECTIVE: To pilot test two low-cost and thus financially sustainable incentive programs to promote physical activity (PA) among low-active adults in a community setting. METHOD: In a three-arm randomized controlled trial the effects of small monetary incentives (cash incentives $1/day; n = 25) were compared to charitable donations (donation $1/day; n = 25) and a control group (n = 25) on PA behavior over the course of 12 months in insufficiently active, otherwise healthy adults. Incentives were based on attendance at a local YMCA. Electronic swipe card data from the YMCA was the primary outcome, with self-reported minutes of PA as a secondary outcome. RESULTS: Quantile regression models showed promising effects of treatment allocation on the primary outcome (attendance) adjusted for age and employment. There was a difference between cash incentives and control conditions such that median attendance in the cash incentives condition was 19.24 visits more over 12 months (b = 19.24; SE = 8.26, 95% CI [2.75, 35.72]). There was a similar though only marginally significant trend for the donation condition showing that participants in the donation condition made 11.88 additional visits to the YMCA over 12 months relative to the control condition (b = 11.88, SE = 8.41,95% CI [-0.91, 28.67]). There was a significant correlation between objectively verified YMCA attendance and self-reported moderate-to-vigorous PA at the YMCA (ρ = 0.587) over 12 months. CONCLUSIONS: These promising findings provide early support for small monetary incentives and charitable donations for promoting PA in community settings. Further research on the efficacy of using financially sustainable incentive programs, including charitable donations, for PA through community organizations (e.g., YMCAs) seems warranted. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Are self-efficacy measures confounded with motivation? An experimental test.

Standard measures of self-efficacy (SE) may confound perceived capability and motivation because respondents interpret the word "can" as "will". Objective: To test whether priming for the meaning of the word "can" changes self-efficacy ratings. Design: In an experimental test, 134 university students responded to an on-line standardized measure of exercise SE and provided definitions of the words "can" and "will". One month later participants were randomized to complete (a) the same questionnaire (control), (b) the same questionnaire but with presentation of each participant's definition of "can" prior to the SE measure (definition priming), or (c) the same questionnaire but with SE items ("I can exercise…") placed side-by-side with behavioral intention items ("I will exercise…") (side-by-side priming). Results: SE increased relative to controls for side-by-side (b = 12.08, SE = 2.70, p<.01) but not definition priming (ns), with the former even stronger among participants (n = 91) who provided strict (i.e., literal) rather than liberal definitions of "can" (b = 15.38, SE = 3.21, p<.001). Conclusion: Priming of the meaning of the word "can" led to increases in self-efficacy ratings among those who hold a literal meaning of the word "can". This suggests that for many respondents standard assessments of SE may be confounded by motivation.

RETROSPECTIVE EVALUATION OF HEPATOCELLULAR NEOPLASMS IN NILE LECHWE (KOBUS MEGACEROS) FROM TWO FLORIDA ZOOLOGICAL INSTITUTIONS.

This case series describes hepatocellular neoplasms in 10 Nile lechwe (Kobus megaceros) at two separate zoological institutions in Florida. Histologically, the neoplasms were classified as hepatocellular carcinoma (n = 7), hepatocellular adenoma (n = 2), and hepatobiliary carcinoma (n = 1). Common clinical signs were nonspecific and included thin body condition (n =7), lethargy (n =6), lameness (n =3), and acute recumbency (n =5). Four males and six females were affected, and the mean age at death was 12.7 yr with a range of 4-18 yr. All cases were diagnosed postmortem, and metastasis to various sites, including lung, lymph nodes, and omentum, was found in 40% of cases (n = 4). A single case of hepatocellular carcinoma in a Nile lechwe was described in 2007; however, this is the first reported series of neoplasms in Reduncinae. The pathogenesis behind the development of hepatocellular neoplasms in Nile lechwe has not yet been identified.

Reciprocal within-day associations between incidental affect and exercise: An EMA study.

Previous research suggests that how people feel throughout the course of a day (i.e. incidental affect) is predictive of exercise behaviour. A mostly separate literature suggests that exercise can lead to more positive incidental affect. OBJECTIVE: This study examines the potential reciprocal effects of incidental affect and exercise behaviour within the same day. DESIGN: Fifty-nine low-active (exercise <60 min/week), overweight (BMI: 25.0-39.9) adults (ages 18-65) participated in a six-month print-based exercise promotion programme. MAIN OUTCOME MEASURES: Ecological momentary assessment was used to record self-reported exercise sessions in real time and incidental affective valence (feeling good/bad) as assessed by the 11-point Feeling Scale at random times throughout the day. RESULTS: Use of a within-subjects cross-lagged, autoregressive model showed that participants were more likely to exercise on days when they experienced more positive incidental affect earlier in the day (b = .58, SE = .10, p < .01), and participants were more likely to experience more positive incidental affect on days when they had exercised (b = .26, SE = .03, p < .01), with the former association significantly stronger than the latter (t = 23.54, p < .01). CONCLUSION: The findings suggest a positive feedback loop whereby feeling good and exercising are reciprocally influential within the course of a day.

The Exercise-Affect-Adherence Pathway: An Evolutionary Perspective.

The low rates of regular exercise and overall physical activity (PA) in the general population represent a significant public health challenge. Previous research suggests that, for many people, exercise leads to a negative affective response and, in turn, reduced likelihood of future exercise. The purpose of this paper is to examine this exercise-affect-adherence relationship from an evolutionary perspective. Specifically, we argue that low rates of physical exercise in the general population are a function of the evolved human tendency to avoid unnecessary physical exertion. This innate tendency evolved because it allowed our evolutionary ancestors to conserve energy for physical activities that had immediate adaptive utility such as pursuing prey, escaping predators, and engaging in social and reproductive behaviors. The commonly observed negative affective response to exercise is an evolved proximate psychological mechanism through which humans avoid unnecessary energy expenditure. The fact that the human tendencies toward negative affective response to and avoidance of unnecessary physical activities are innate does not mean that they are unchangeable. Indeed, it is only because of human-engineered changes in our environmental conditions (i.e., it is no longer necessary for us to work for our food) that our predisposition to avoid unnecessary physical exertion has become a liability. Thus, it is well within our capabilities to reengineer our environments to once again make PA necessary or, at least, to serve an immediate functional purpose. We propose a two-pronged approach to PA promotion based on this evolutionary functional perspective: first, to promote exercise and other physical activities that are perceived to have an immediate purpose, and second, to instill greater perceived purpose for a wider range of physical activities. We posit that these strategies are more likely to result in more positive (or less negative) affective responses to exercise, better adherence to exercise programs, and higher rates of overall PA.

Self-Paced Exercise, Affective Response, and Exercise Adherence: A Preliminary Investigation Using Ecological Momentary Assessment.

Affective response to exercise may mediate the effects of self-paced exercise on exercise adherence. Fiftynine low-active (exercise <60 min/week), overweight (body mass index: 25.0-39.9) adults (ages 18-65) were randomly assigned to self-paced (but not to exceed 76% maximum heart rate) or prescribed moderate intensity exercise (64-76% maximum heart rate) in the context of otherwise identical 6-month print-based exercise promotion programs. Frequency and duration of exercise sessions and affective responses (good/bad) to exercise were assessed via ecological momentary assessment throughout the 6-month program. A regression-based mediation model was used to estimate (a) effects of experimental condition on affective response to exercise (path a = 0.20, SE = 0.28, f2 = 0.02); (b) effects of affective response on duration/latency of the next exercise session (path b = 0.47, SE = 0.25, f2 = 0.04); and (c) indirect effects of experimental condition on exercise outcomes via affective response (path ab = 0.11, SE = 0.06, f2 = 0.10). Results provide modest preliminary support for a mediational pathway linking self-paced exercise, affective response, and exercise adherence.