Physical activity and exercise guidelines for weight management call for at least 60 min of daily activity. However, these documents fail to acknowledge that almost no obese adults meet this target and that non-adherence and dropout are even higher among obese individuals than the general population. The reasons for this level of activity avoidance among obese individuals remain poorly understood, and there are no evidence-based methods for addressing the problem. Opinions among exercise scientists are polarized. Some advocate moderate intensity and long duration, whereas others call for high intensity and shorter duration. The latter approach attributes the inactivity and high dropout to limited discretionary time and the slow accrual of visible benefits. However, higher intensity has been associated with non-adherence and dropout, whereas longer duration has not. A conceptual model is then proposed, according to which obesity interacts with intensity, causing physical activity and exercise to be associated with reduced pleasure among obese individuals. We theorize that, in turn, repeated experiences of reduced pleasure lead to avoidance. On this basis, we call for a research agenda aimed at identifying the causes of activity-associated and exercise-associated displeasure in obesity and, by extension, the causes of the extreme physical inactivity among obese individuals.

Electroencephalographic (EEG) and self-report measures of affect were obtained from 27 participants (14 F, 13 M) before, during, and following 30 min of continuous exercise at low and high intensities to determine the respective temporal courses of affective response. Mood was measured via a visual analog mood scale (VAMS), the Positive and Negative Affect Schedules (PANAS-PA and -NA), and EEG hemispheric asymmetry as obtained from three electrode pairs: F4-F3, F8-F7, and P4-P3. Participants reported higher VAMS and lower PANAS-NA scores during low-intensity exercise relative to baseline, and the higher scores were maintained during recovery. In contrast, they reported lower scores on the VAMS during high-intensity exercise relative to baseline that were subsequently elevated during recovery. Also, during high-intensity exercise the PANAS-NA scores were similar to baseline, but they were lower during recovery. Both the VAMS and PANAS-NA scores observed after exercise were similar regardless of intensity. Additionally, participants had higher PANAS-PA and EEG hemispheric asymmetry scores (i.e., F8-F7) during exercise at both intensities relative to baseline, then reported values similar to baseline levels on cessation of work. The magnitude of change from baseline for the PANAS-PA and EEG scores during exercise was similar regardless of exercise intensity.

The results support specificity of the physical activity/cognition relationship in older individuals. The results may be explained by additive benefit from participation in physical activity to the frontal lobe (i.e., beyond any benefits from cognitive stimulation), a region that mediates executive function and experiences accelerated age-related decline. In summary, habitual physical activity is positively related to executive performance in older men and women into the 10th decade.

Our previous study has demonstrated that 6 weeks of Tai Chi exercise significantly improves knee pain and stiffness in elderly with knee osteoarthritis. This study also examine the effects of Tai Chi exercise on gait kinematics, physical function, pain, and pain self-efficacy in elderly with knee osteoarthritis. In this prospective, pretest-posttest clinical trial, 40 men and women (64.4+/-8.3 years) diagnosed with knee osteoarthritis participated in 6 weeks of instructed Tai Chi training, 1 hour/session, 2 sessions/week. The following measures were taken at baseline and the conclusion of the intervention: (a) gait kinematics including stride length, stride frequency, and gait speed quantified using video analysis, (b) physical function, (c) knee pain, and (d) pain self-efficacy. Data were analyzed using repeated MANCOVA, MANOVA, ANOVA and Wilcoxon tests. After 6 weeks of Tai Chi exercise, stride length (p=0.023; 1.17+/-0.17 vs. 1.20+/-0.14 m), stride frequency (p=0.014; 0.91+/-0.08 vs. 0.93+/-0.08 strides/s), and consequently gait speed (p<0.025; 1.06+/-0.19 vs. 1.12+/-0.15 m/s) increased in the participants. Physical function was significantly improved (p<0.001) and knee pain was significantly decreased (p=0.002), while no change was observed in pain self-efficacy. In conclusion, these findings support that Tai Chi is beneficial for gait kinematics in elderly with knee osteoarthritis, and a longer term application is needed to substantiate the effect of Tai Chi as an alternative exercise in management of knee osteoarthritis.

The purpose of this study was to test the transient hypofrontality theory (Dietrich, 2003) by examining the influence of exercise intensity on executive control processes during and following submaximal exercise. Thirty participants (13 female) exercised for 30 min at ventilatory threshold (VT) or at 75% of VT. The Contingent Continuous Performance Task (CPT) and Wisconsin Card Sorting Test (WCST) were used as measures of executive control. They were administered before, during, immediately following, and 20 min after exercise. An increase in false alarms and unique errors (p ≤ .05) occurred during both conditions. False alarms for the CPT and total and perseverative errors for the WCST remained elevated immediately following exercise at VT, but not at exercise below VT (p ≤ .01). The decreased executive control function during exercise can be explained by the transient hypofrontality theory. Following VT, executive control performance remained poor possibly owing to an additional amount of time the brain needs to return to homeostasis following intense exercise.

The purpose of this study was to examine the influence of exercise order on blood lactate, perceptual, and affective responses to resistance exercise. Twenty-nine subjects (18 women, 11 men; 20.9 +/- 1.9 years) completed three sessions separated by a minimum of 48 hours. Session 1 determined the 10-repetition maximum (10RM) for nine resistance exercises. During sessions 2 and 3, exercises were completed in either a large to small or small to large muscle exercise order. The large to small muscle order was 1) chest press, 2) leg press, 3) rows, 4) leg extension, 5) overhead press, 6) hamstring curl, 7) biceps curl, 8) calve raise, and 9) triceps extension. Exercise order was reversed for the small to large condition. Participants performed two sets of each lift, with the first set being a warm-up at 80% 10RM, followed by one set at 100% 10RM with 1 minute of rest between each exercise. Rating of perceived exertion (RPE) was measured after completion of the second set. Blood lactate was recorded after exercises 1, 5, and 9. Affective measures were completed pre, during, post 0, and post 10 minutes. Lactate showed a significant time (p < 0.001) and condition x time interaction (p = 0.020). A significant difference was seen in average number of repetitions completed between sequences, with small to large performing more. There were no differences seen between exercise orders for average RPE. Analyses of Feeling Scale and Felt Arousal Scale scores showed only a significant main effect of time. A paired-sample t-test was conducted to examine differences in Feeling Scale for the two conditions at the different time points. Significant differences were found for Feeling Scale during exercise (after overhead press) and at post 10, with the small to large exercise order having greater Feeling Scale responses. No significant correlations were seen between blood lactate and perceptual or affective responses at any time point or in either exercise order. These findings may suggest that small to large exercise order may have beneficial physiological and psychological outcomes and potentially influence exercise adherence.

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Performance in fitness tests could depend on factors beyond the bioenergetic and skeletomuscular systems, such as individual differences in preference for and tolerance of different levels of exercise-induced somatosensory stimulation. Although such individual-difference variables could play a role in exercise testing and prescription, they have been understudied. The purpose of these studies was to examine the relationships of self-reported preference for and tolerance of exercise intensity with performance in fitness tests. Participants in study I were 516 men and women volunteers from a campus community, and participants in study II were 42 men recruit firefighters undergoing a 6-week training program. Both the Preference and Tolerance scores exhibited significant relationships with performance in several fitness tests and with body composition and physical activity participation. Preference and Tolerance did not change after the training program in study II, despite improvements in objective and perceived fitness, supporting their conceptualization as dispositional traits. Preference and Tolerance scores could be useful not only in ameliorating the current understanding of the determinants of physical performance, but also in personalizing exercise prescriptions and, thus, delivering exercise experiences that are more pleasant, tolerable, and sustainable.