Self-reported tolerance influences prefrontal cortex hemodynamics and affective responses

The relationship between cognitive and sensory processes in the brain contributes to the regulation of affective responses (pleasure–displeasure). Exercise can be used to manipulate sensory processes (by increasing physiological demand) in order to examine the role of dispositional traits that may influence an individual’s ability to cognitively regulate these responses. With the use of near infrared spectroscopy, in this study we examined the influence of self-reported tolerance upon prefrontal cortex (PFC) hemodynamics and affective responses. The hemodynamic response was measured in individuals with high or low tolerance during an incremental exercise test. Sensory manipulation was standardized against metabolic processes (ventilatory threshold [VT] and respiratory compensation point [RCP]), and affective responses were recorded. The results showed that the high-tolerance group displayed a larger hemodynamic response within the right PFC above VT (which increased above RCP). The low-tolerance group showed a larger hemodynamic response within the left PFC above VT. The high-tolerance group reported a more positive/less negative affective response above VT. These findings provide direct neurophysiological evidence of differential hemodynamic responses within the PFC that are associated with tolerance in the presence of increased physiological demands. This study supports the role of dispositional traits and previous theorizing into the underlying mechanisms (cognitive vs. sensory processes) of affective respons

Prefrontal cortex haemodynamics and affective responses during exercise: a multi-channel near infrared spectroscopy study

The dose-response effects of the intensity of exercise upon the potential regulation (through top-down processes) of affective (pleasure-displeasure) responses in the prefrontal cortex during an incremental exercise protocol have not been explored. This study examined the functional capacity of the prefrontal cortex (reflected by haemodynamics using near infrared spectroscopy) and affective responses during exercise at different intensities. Participants completed an incremental cycling exercise test to exhaustion. Changes (Δ) in oxygenation (O2Hb), deoxygenation (HHb), blood volume (tHb) and haemoglobin difference (HbDiff) were measured from bilateral dorsal and ventral prefrontal areas. Affective responses were measured every minute during exercise. Data were extracted at intensities standardised to: below ventilatory threshold, at ventilatory threshold, respiratory compensation point and the end of exercise. During exercise at intensities from ventilatory threshold to respiratory compensation point, ΔO2Hb, ΔHbDiff and ΔtHb were greater in mostly ventral than dorsal regions. From the respiratory compensation point to the end of exercise, ΔO2Hb remained stable and ΔHbDiff declined in dorsal regions. As the intensity increased above the ventilatory threshold, inverse associations between affective responses and oxygenation in (a) all regions of the left hemisphere and (b) lateral (dorsal and ventral) regions followed by the midline (ventral) region in the right hemisphere were observed. Differential activation patterns occur within the prefrontal cortex and are associated with affective responses during cycling exercise

Can previously sedentary females use the feeling scale to regulate exercise intensity in a gym environment? an observational study

Background Recent research suggests that the Feeling Scale (FS) can be used as a method of exercise intensity regulation to maintain a positive affective response during exercise. However, research to date has been carried out in laboratories and is not representative of natural exercise environments. The purpose of this study was to evaluate whether sedentary women can self-regulate their exercise intensity using the FS to experience positive affective responses in a gym environment using their own choice of exercise mode; cycling or treadmill. Methods Fourteen females (24.9 years ± 5.2; height 166.7 ± 5.7 cm; mass 66.3 ± 13.4 kg; BMI 24.1 ± 5.5)) completed a submaximal exercise test and each individual’s ventilatory threshold (V˙T) was identified. Following this, three 20 min gym-based exercise trials, either on a bike or treadmill were performed at an intensity that was self-selected and perceived to correspond to the FS value of +3 (good). Oxygen uptake, heart rate (HR) and ratings of perceived exertion (RPE) were measured during exercise at the participants chosen intensity. Results Results indicated that on average participants worked close to their V˙T and increased their exercise intensity during the 20-min session. Participants worked physiologically harder during cycling exercise. Consistency of oxygen uptake, HR and RPE across the exercise trials was high. Conclusion The data indicate that previously sedentary women can use the FS in an ecological setting to regulate their exercise intensity and that regulating intensity to feel ‘good’ should lead to individuals exercising at an intensity that would result in cardiovascular gains if maintained

Effort Perception

Research addressing children's perceptions of exercise effort (their ‘perceived exertion’) has appeared steadily in the scientific literature over the last 30 years. Accepting that the established Borg adult rating of perceived exertion (RPE) scale was not appropriate for children, investigators set about developing child-specific scales which employed numbers, words and/or images that were more familiar and understandable. Numerous studies have examined the validity and reliability of such scales as the CERT, PCERT and OMNI amongst children aged 5 to 16, across different modes of exercise (cycling, running, stepping, resistance exercise), protocols (intermittent vs. continuous, incremental vs. non-incremental) and paradigms (estimation vs. production). Such laboratory-based research has enabled the general conclusion that children can, especially with practice, use effort perception scales to differentiate between exercise intensity levels, and to self-regulate their exercise output to match various levels indicated on them. However, inconsistencies in the methodological approaches adopted diminish the certainty of some of the interpretations made by researchers. In addition, though often mentioned, the would-be application of effort perception in physical education and activity/health promotion contexts has been relatively ignored. Accordingly, the scope for research in this applied domain is now considerable

Development of a Self-Determination Theory-Based Physical Activity Intervention for Aged Care Workers: Protocol for the Activity for Well-being Program

Despite the well-established benefits of regular participation in physical activity, many Australians still fail to maintain sufficient levels. More self-determined types of motivation and more positive affect during activity have been found to be associated with the maintenance of physical activity behaviour over time. Need-supportive approaches to physical activity behaviour change have previously been shown to improve quality of motivation and psychological well-being. This paper outlines the development of a need-supportive, person-centred physical activity program for frontline aged-care workers. The program emphasises the use of self-determined methods of regulating activity intensity (affect, rating of perceived exertion and self-pacing) and is aimed at increasing physical activity behaviour and psychological well-being. The development process was undertaken in six steps using guidance from the Intervention Mapping framework: (i) an in-depth needs assessment (including qualitative interviews where information was gathered from members of the target population); (ii) formation of change objectives; (iii) selecting theory-informed and evidence-based intervention methods and planning their practical application; (iv) producing program components and materials; (v) planning program adoption and implementation, and (vi) planning for evaluation. The program is based in Self-Determination Theory (SDT) and provides tools and elements to support autonomy (the use of a collaboratively developed activity plan and participant choice in activity types), competence (action/coping planning, goal-setting and pedometers), and relatedness (the use of a motivational interviewing-inspired appointment and ongoing support in activity)

Misperception: No evidence to dismiss RPE as regulator of moderate-intensity exercise

This document is the Accepted Manuscript version of a published work that appeared in final form in Medicine and Science in Sport and Exercise. To access the final edited and published work see https://doi.org/10.1249/MSS.0000000000000748.Dear Editor-in-Chief, Shaykevich et al. (7) demonstrate the efficacy of auditory feedback anchored at 75% of age-predicted HRmax to regulate intensity (claimed as ‘‘moderate’’) during several 20-min bouts of cycling. Their technical approach is novel, but 76% HRmax is the upper limit of moderate intensity, so given the large error in age-predicted HRmax, it is unlikely that their exercise bandwidth was ‘‘moderate’’ for all participants. This is not our major concern, but it reveals one among other inaccuracies: the most serious include training, interpretation, and inferences relating to the RPE

Effects of low-fat diets differing in protein and carbohydrate content on cardiometabolic risk factors during weight loss and weight maintenance in obese adults with type 2 diabetes

Despite evidence for the benefits of higher-protein (HP) diets in weight loss, their role in type 2 diabetes mellitus (T2DM) management and weight maintenance is not clear. This randomised study compared the effects of a HP diet (38% carbohydrate, 30% protein, 29% fat) to a isocaloric higher-carbohydrate diet (HC: 53%:21%:23%) on cardiometabolic risk factors for 12 weeks in energy restriction (~30% reduction) followed by 12 weeks of energy balance whilst performing regular exercise. Outcomes were measured at baseline and the end of each phase. Sixty-one overweight/obese adults (BMI (body mass index) 34.3 ± 5.1 kg/m2, aged 55 ± 8 years) with T2DM who commenced the study were included in the intention-to-treat analysis including the 17 participants (HP n = 9, HC n = 8) who withdrew. Following weight loss (M ± SEM: -7.8 ± 0.6 kg), there were significant reductions in HbA1c (–1.4% ± 0.1%, p < 0.001) and several cardiometabolic health risk factors. Improvements were sustained for 12 weeks when weight was stabilised and weight loss maintained. Both the HP and HC dietary patterns with concurrent exercise may be effective strategies for weight loss and weight maintenance in T2DM although further studies are needed to determine the longer term effects of weight maintenance

Effect of a 12-week online walking intervention on health and quality of life in cancer survivors: a quasi-randomized controlled trial

Cancer survivors are at an increased risk of experiencing physical and psychological ill-effects following cancer treatment. Rural cancer survivors are at a greater risk of future health problems following a cancer diagnosis compared to their urban counterparts. Physical activity has been targeted as a health promotion priority in cancer survivors. Research indicates that a large portion of cancer survivors do not meet physical activity recommendations. The purpose of this quasi-randomized controlled trial was to test the effectiveness of an online 12-week walking intervention designed for cancer survivors, and to explore its impact on physical health indicators and quality of life outcomes. Steps Toward Improving Diet and Exercise among cancer survivors (STRIDE) is an online resource designed according to Social Cognitive Theory and Self Determination Theory, based on individualized step goal setting. Measures of physiology, physical fitness, and quality of life were taken at the baseline, post-intervention, and three-month follow-up in an Intervention group (n = 46) and active Control group (n = 45). The Control group was provided with a pedometer but did not have access to the online program. Three-factor repeated measures ANOVAs indicated that there were improvements in physical fitness (p < 0.01), systolic blood pressure (p < 0.01), diastolic blood pressure (p < 0.01), waist girth (p < 0.01), mental health (p < 0.05), social functioning (p < 0.01), and general health (p < 0.01), but an increase in bodily pain (p < 0.01), from the baseline to week 12 and the three-month follow-up, irrespective of group allocation. Pedometer interventions, delivered with or without online support and step goal setting, show promise for improving the overall health of cancer survivors, at least in the short term.Lauren J. Frensham, Gaynor Parfitt and James Dollma

Exercisers’ Affective and Enjoyment Responses: A Meta-Analytic and Meta-Regression Review

Affective responses and enjoyment of exercise mediate exercise adherence, but previous research findings have failed to examine nuances that may moderate this relationship. We examined the effects of exercise on affective and enjoyment responses during and post exercise through a systematic literature review and meta-regression analysis. We searched major databases up to July 9, 2020 for studies evaluating healthy adults' acute and chronic responses to exercise, using either of The Feeling Scale or Physical Activity Enjoyment Scales. We calculated effect size (ES) values of 20 unique studies (397 participants; 40% females) as standardized differences in the means and expressed them as Hedges' g, together with the 95% confidence interval (95%CI). Among acute studies examining affective responses, we found a greater positive effect post exercise for continuous training (CT) compared to high intensity interval training (HIIT) (g = -0.61; 95%CI = -1.11, -0.10; p < .018), but there was no significant difference between these modes for effects during exercise. Subgroup analyses revealed that moderate, and not high intensity, CT, compared to HIIT, resulted in significantly greater positive affective responses (g = -1.09; 95%CI = -1.88, -0.30; p < .006). In contrast, enjoyment was greater for HIIT, compared to CT (g = 0.75; 95%CI = 0.17, -1.13; p = .010), but CT intensity did not influence this result. Among chronic studies, there was greater enjoyment following HIIT compared to CT, but these studies were too few to permit meta-analysis. We concluded that an acute bout of moderate intensity CT is more pleasurable, when measured post exercise than HIIT, but enjoyment is greater following HIIT, perhaps due to an interaction between effort, discomfort, time efficiency and constantly changing stimuli

Reducing Sitting Time After Stroke: A Phase II Safety and Feasibility Randomized Controlled Trial. ( Presented in part as a poster to the European Stroke Organization, April 17–19, 2015, Glasgow, United Kingdom; and Stroke 2015 (a combined conference of the Stroke Society of Australasia and Smartstrokes NSW), September 1–5, 2015, Melbourne, VIC, Australia.)

OBJECTIVE: To test the safety, feasibility, and effectiveness of reducing sitting time in stroke survivors. DESIGN: Randomized controlled trial with attention-matched controls and blinded assessments. SETTING: Community. PARTICIPANTS: Stroke survivors (N=35; 22 men; mean age, 66.9±12.7y). INTERVENTIONS: Four counseling sessions over 7 weeks with a message of sit less and move more (intervention group) or calcium for bone health (attention-matched control group). MAIN OUTCOME MEASURES: Measures included safety (adverse events, increases in pain, spasticity, or fatigue) and feasibility (adherence to trial protocol). Secondary measures included time spent sitting (including in prolonged bouts ≥30min), standing, and stepping as measured by the thigh-worn inclinometer (7d, 24h/d protocol) and time spent in physical activity of at least moderate intensity as measured by a triaxial accelerometer. The Multimedia Activity Recall for Children and Adults was used to describe changes in use of time. RESULTS: Thirty-three participants completed the full protocol. Four participants reported falls during the intervention period with no other adverse events. From a baseline average of 640.7±99.6min/d, daily sitting time reduced on average by 30±50.6min/d (95% confidence interval [CI], 5.8-54.6) in the intervention group and 40.4±92.5min/d in the control group (95% CI, 13.0-93.8). Participants in both groups also reduced their time spent in prolonged sitting bouts (≥30min) and increased time spent standing and stepping. CONCLUSIONS: Our protocol was both safe and feasible. Participants in both groups spent less time sitting and more time standing and stepping postintervention, but outcomes were not superior for intervention participants. Attention matching is desirable in clinical trials and may have contributed to the positive outcomes for control participants