Effect of high-intensity interval training on cardiometabolic component risks in persons with paraplegia: Results of a randomized controlled trial.

The aim of this work is to determine the effect of upper-body high intensity interval training (HIIT) on cardiometabolic risks in individuals with chronic paraplegia. Twenty-seven individuals (14 females, 13 males, mean ± SD age: 46 ± 9 years) with chronic paraplegia (spinal cord injury between T2 and L5 >1-year post-injury) took part in a randomized controlled trial and were included in the final analysis. Participants in the HIIT group (n = 18) performed ∼30 min of arm crank exercise (60 s intervals at 80%-90% peak heart rate) four times per week, for 6 weeks. Participants in the control (CON) group (n = 9) were asked to maintain their habitual diet and physical activity patterns over the study period. Outcome measures were taken at baseline and follow-up. The primary outcome measures were fasting insulin, peak power output (PPO) and peak aerobic capacity ( V ̇ O 2 peak ${{\dot{V}}_{{{{\mathrm{O}}}_{\mathrm{2}}}{\mathrm{peak}}}}$ ). Secondary outcome measures included body composition, postprandial glycaemic control, fasting blood lipids, inflammatory biomarkers and resting blood pressure. Differences between groups were assessed by ANCOVA, using baseline values as a covariate. PPO was higher in the HIIT (101 W, 97-106) compared to the CON (90 W, 83-96) group at follow-up (P = 0.006). There were no differences in fasting insulin (P = 0.415) or relative V ̇ O 2 peak ${{\dot{V}}_{{{{\mathrm{O}}}_{\mathrm{2}}}{\mathrm{peak}}}}$ (P = 0.417). Postprandial Matsuda insulin sensitivity index (ISIMatsuda) was higher in the HIIT (5.42, 4.69-6.15) compared to the CON (3.75, 2.46-5.04) group at follow-up (P = 0.036). Six weeks of upper-body HIIT increased PPO and ISIMatsuda, with no other beneficial effect on cardiometabolic component risks in persons with chronic paraplegia. HIGHLIGHTS: What is the central question of this study? What is the effect of upper-body high intensity interval training (HIIT) on cardiometabolic component risks in individuals with chronic paraplegia? What is the main finding and its importance? Six weeks of upper-body HIIT increased PPO and improved insulin sensitivity, but had no beneficial effect on other cardiometabolic component risks in persons with chronic paraplegia. The large effect size observed for insulin sensitivity may be important in terms of reducing the risk of type-2 diabetes in this population.

Influence of the intelligent knee osteoarthritis lifestyle app (iKOALA) on knee joint pain.

BACKGROUND: The intelligent knee osteoarthritis lifestyle app (iKOALA) has been co-developed with target users to extend the support for physical activity (PA) and musculoskeletal health, beyond short-term structured rehabilitation, using personalised PA guidance, education, and social support. The purpose of this study was to assess the preliminary effectiveness and usability of the iKOALA digital intervention on indices of musculoskeletal (MSK) health, symptoms, and physical activity levels in a broad range of individuals with knee osteoarthritis (KOA) over 12 weeks to inform the design of a larger randomised controlled trial. METHODS: Thirty-eight (33 female) participants living in the UK with a mean (SD) age of 58 (± 9) years diagnosed radiographically or clinically with KOA completed a 12-week user trial of the iKOALA. Participants completed an in-app physical activity questionnaire which intelligently recommended suitable strengthening and aerobic based activities to individuals. Throughout the trial, participants wore a physical activity monitor and were given access to functions within the app (physical activity (PA) reminders, information and education, symptom and PA tracking as well as social support forums) to support them in maintaining their PA plan. Participants completed a MSK questionnaire for chronic symptoms and quality of life (MSK-HQ) as well as an acute iKOALA symptoms questionnaire (confidence, fatigue, mood, pain during the day/night, sleep and ability to walk) in the week prior to starting and following completion of the trial. RESULTS: Physical activity levels were consistent over the 12 weeks with total daily steps of 9102 (± 3514) in week 1, 9576 (± 4214) in week 6 and 9596 (± 3694) in week 12. Group mean changes in all iKOALA MSK symptom scores and the total MSK-HQ (pre 33.1 (7.6) vs. post 40.2 (7.6)) score improved significantly (p < .001, 95% CI [-8.89, -5.16]) over the 12-week period. CONCLUSIONS: Physical activity levels were maintained at a high level throughout the 12 weeks. Significant improvements in mean MSK symptom scores and the total MSK-HQ score were also observed. Efforts to ensure more generalised reach amongst sex and socioeconomic status of the digital intervention in a randomised controlled clinical trial are warranted.

Development of the intelligent knee osteoarthritis lifestyle app: a person-based approach.

BACKGROUND: Knee osteoarthritis is one of the most prevalent long term health conditions globally. Exercise and physical activity are now widely recognised to significantly reduce joint pain, improve physical function and quality of life in patients with knee osteoarthritis. However, prescribed exercise without regular contact with a healthcare professional often results in lower adherence and poorer health outcomes. Digital mobile health (mHealth) technologies offer great potential to support people with long-term conditions such as knee osteoarthritis more efficiently and effectively and with relatively lower cost than existing interventions. However, there are currently very few mHealth interventions for the self-management of knee osteoarthritis. The aim of the present study was to describe the development process of a mHealth app to extend the support for physical activity and musculoskeletal health beyond short-term, structured rehabilitation through self-management, personalised physical activity, education, and social support. METHODS: The development of the intelligent knee osteoarthritis lifestyle application intervention involved an iterative and interconnected process comprising intervention 'planning' and 'optimisation' informed by the person-based approach framework for the development of digital health interventions. The planning phase involved a literature review and collection of qualitative data obtained from focus groups with individuals with knee osteoarthritis (n = 26) and interviews with relevant physiotherapists (n = 5) to generate 'guiding principles' for the intervention. The optimisation phase involved usability testing (n = 7) and qualitative 'think aloud' sessions (n = 6) with potential beneficiaries to refine the development of the intervention. RESULTS: Key themes that emerged from the qualitative data included the need for educational material, modifying activities to suit individual abilities and preferences as well as the inclusion of key features such as rehabilitation exercises. Following a user-trial further changes were made to improve the usability of the application. CONCLUSIONS: Using a systematic person-based, development approach, we have developed the intelligent knee osteoarthritis lifestyle application to help people maintain physical activity behaviour. The app extends the support for physical activity and musculoskeletal health beyond short-term, structured rehabilitation through personalised physical activity guidance, education, and social support.

Post-exercise skimmed milk, but not a sucrose beverage decreases energy intake at the next meal compared to a placebo beverage in active males.

This study compared the appetite and energy intake effects of three post-exercise beverages at a subsequent post-exercise meal. On three occasions, ten active males: (mean ± sd) age 21.3 ± 1.2 y, V˙ O2peak 58 ± 5 mL/kg/min) performed 30-min cycling at ∼60% V˙ O2peak and five 4-min intervals at 85% V˙ O2peak. Post-exercise, placebo (PLA: 57 kJ), skimmed milk (MILK: 1002 kJ) or sucrose (CHO: 1000 kJ) beverages (615 mL) were consumed. Sixty min post-beverage, subjects consumed an ad-libitum pasta lunch in a 30 min eating period. Subjective appetite and plasma acylated ghrelin and plasma glucose were determined pre-exercise, post-exercise and pre-meal, with sensory characteristics of beverages rated. Ad-libitum energy intake in MILK (6746 ± 2035) kJ) was lower than CHO (7762 ± 1921) kJ) (P = 0.038; dz = 0.98; large effect) and tended to be lower than PLA (7672 (2005) kJ) (P = 0.078; dz = 0.76; medium effect). Including energy consumed in beverages, energy intake was greater in CHO than PLA (P = 0.010; dz = 1.24; large effect) or MILK (P = 0.026; dz = 0.98; large effect), with PLA and MILK not different (P = 0.960; dz = 0.02; trial effect). Plasma ghrelin, plasma glucose and appetite were not different between trials. MILK was perceived thicker than CHO (P = 0.020; dz = 1.11; large effect) and creamier than PLA (P = 0.026; dz = 1.06; large effect). These results suggest that when energy balance is important for an exerciser, post-exercise skimmed milk ingestion reduces energy intake compared to a sucrose beverage and might therefore help facilitate recovery/adaptation without affecting energy balance.

ADAPTations to low load blood flow restriction exercise versus conventional heavier load resistance exercise in UK military personnel with persistent knee pain: protocol for the ADAPT study, a multi-centre randomized controlled trial.

BACKGROUND: Muscle atrophy, muscle weakness and localised pain are commonly reported following musculoskeletal injury (MSKI). To mitigate this risk and prepare individuals to return to sport or physically demanding occupations, resistance training (RT) is considered a vital component of rehabilitation. However, to elicit adaptations in muscle strength, exercise guidelines recommend lifting loads ≥ 70% of an individual's one repetition maximum (1-RM). Unfortunately, individuals with persistent knee pain are often unable to tolerate such high loads and this may negatively impact the duration and extent of their recovery. Low load blood flow restriction (LL-BFR) is an alternative RT technique that has demonstrated improvements in muscle strength, hypertrophy, and pain in the absence of high mechanical loading. However, the effectiveness of high-frequency LL-BFR in a residential rehabilitation environment remains unclear. This study will compare the efficacy of high frequency LL-BFR to 'conventional' heavier load resistance training (HL-RT) on measures of physical function and pain in adults with persistent knee pain. METHODS: This is a multicentre randomised controlled trial (RCT) of 150 UK service personnel (aged 18-55) admitted for a 3-week residential rehabilitation course with persistent knee pain. Participants will be randomised to receive: a) LL-BFR delivered twice daily at 20% 1-RM or b) HL-RT three-times per week at 70% 1-RM. Outcomes will be recorded at baseline (T1), course discharge (T2) and at three-months following course (T3). The primary outcome will be the lower extremity functional scale (LEFS) at T2. Secondary outcomes will include patient reported perceptions of pain, physical and occupational function and objective measures of muscle strength and neuromuscular performance. Additional biomechanical and physiological mechanisms underpinning both RT interventions will also be investigated as part of a nested mechanistic study. DISCUSSION: LL-BFR is a rehabilitation modality that has the potential to induce positive clinical adaptations in the absence of high mechanical loads and therefore could be considered a treatment option for patients suffering significant functional deficits who are unable to tolerate heavy load RT. Consequently, results from this study will have a direct clinical application to healthcare service providers and patients involved in the rehabilitation of physically active adults suffering MSKI. TRIAL REGISTRATION: ClinicalTrials.org reference number, NCT05719922.

Portions selected to stave off hunger are reduced when food is presented in an 'unusual' food-to-mealtime context: An implication for implicit satiety drivers.

Research suggests that the role of expected satiety in influencing portion-size selection is reduced when food is presented in unusual food-to-mealtime contexts; however, the underlying mechanism has not been explored. Other research has revealed that different implicit satiety drivers (e.g., to stop momentary hunger or obtain complete fullness) are associated with different perceived levels of stomach fullness, portion-size selections and can change on instruction. The current study explored whether changes in expected satiety and ideal portions in congruous vs incongruous contexts can be explained by changes in implicit satiety drivers. Another aim was to investigate a previous exploratory finding suggesting that portions selected to stave off hunger are reduced when foods are presented in unusual food-to-mealtime contexts. At two trials (breakfast/lunch), participants (n = 40) selected a portion of typical lunch (pasta) and breakfast (porridge) foods via a psychophysical computer-based method 1) to stave off hunger for 5 h, and 2) as an ideal portion. Participants also indicated their perceived level of stomach fullness associated with 1) each portion, and 2) five implicit satiety drivers. Results revealed that a smaller average portion was selected to stave off hunger in incongruous (vs congruous) food-to-mealtime contexts (531 ± 229 vs 575 ± 236 kcal) (p = 0.008). This suggests that expected satiety is influenced by momentary context; foods are perceived to be more satiating when consumed in unusual (vs usual) contexts. Results also showed that implicit satiety drivers are malleable in regard to the portion size associated with a perceived level of stomach fullness and that this can vary contextually. These findings provide initial evidence to explain the psychological mechanism underlying the contextual differences observed in portion-size selections. Future work should explore longer-term impacts of consuming foods in unusual contexts.

Current appetite influences relative differences in the expected satiety of foods for momentary, but not hypothetical, expected satiety assessments.

Research has shown that expected satiety is highly associated with portion-size selection and can vary (kcal-for-kcal) significantly between foods. However, research has not adequately investigated whether current appetite influences relative differences in the expected satiety of foods. This is important to explore to better understand how current motivational state influences food choice and portion selection. This study used 'hypothetical' and 'momentary' expected-satiety assessments to understand whether methods requiring a reflection on current motivational state [momentary] versus more hypothetical considerations when assessing expected satiety can influence the interpretation of results. It was hypothesised that current appetite would only influence relative differences in expected satiety between foods for momentary, but not hypothetical, expected satiety assessments. Participants (n = 54) were shown images of twelve foods, once when hungry and once when full. In each case, they selected a portion for each food to 1) match the expected satiety of a fixed-portion 'standard' food [hypothetical], and 2) stave off hunger until their next meal [momentary]. Results showed that the relative between-food comparison of expected satiety was stable for hypothetical (p=.73) but not momentary assessments (p<.001) suggesting that while current motivational state may influence food choice and portion selection in the moment, more generalised comparisons of the satiating abilities of foods (learned over a longer period) remain stable. This is important 1) for methods in future studies, as immediate dietary intake does not appear to influence hypothetical expected satiety, thus dietary control is not necessary before participants undertake these assessments, and 2) as it confirms that difficulties associated with dietary regulation may not be due to inaccurate hypothetical judgements about foods, but instead appear to be influenced by contextual nuances that occur in the moment.

Backward Double Integration is a Valid Method to Calculate Maximal and Sub-Maximal Jump Height.

The backward double integration method uses one force plate and could calculate jump height for countermovement jumping, squat jumping and drop jumping by analysing the landing phase instead of the push-off phase. This study compared the accuracy and variability of the forward double integration (FDI), backwards double integration (BDI) and Flight Time + Constant (FT+C) methods, against the marker-based rigid-body modelling method. It was hypothesised that the jump height calculated using the BDI method would be equivalent to the FDI method, while the FT+C method would have reduced accuracy and increased variability during sub-maximal jumping compared to maximal jumping. Twenty-four volunteers performed five maximal and five sub-maximal countermovement jumps, while force plate and motion capture data were collected. The BDI method calculated equivalent mean jump heights compared to the FDI method, with only slightly higher variability (2-3 mm), and therefore can be used in situations where FDI cannot be employed. The FT+C method was able to account for reduced heel-lift distance, despite employing an anthropometrically scaled heel-lift constant. However, across both sub-maximal and maximal jumping, it had increased variability (1.1 cm) compared to FDI and BDI and should not be used when alternate methods are available.

Involvement of GPR37L1 in murine blood pressure regulation and human cardiac disease pathophysiology.

Multiple mouse lines lacking the orphan G protein-coupled receptor, GPR37L1, have elicited disparate cardiovascular phenotypes. The first Gpr37l1 knockout mice study to be published reported a marked elevation in systolic blood pressure (SBP; ∼60 mmHg), revealing a potential therapeutic opportunity. The phenotype differed from our own independently generated knockout line, where male mice exhibited equivalent baseline blood pressure to wild type. Here, we attempted to reproduce the first study by characterizing the cardiovascular phenotype of both the original knockout and transgenic lines alongside a C57BL/6J control line, using the same method of blood pressure measurement. The present study supports the findings from our independently developed Gpr37l1 knockout line, finding that SBP and diastolic blood pressure (DBP) are not different in the original Gpr37l1 knockout male mice (SBP: 130.9 ± 5.3 mmHg; DBP: 90.7 ± 3.0 mmHg) compared with C57BL/6J mice (SBP: 123.1 ± 4.1 mmHg; DBP: 87.0 ± 2.7 mmHg). Instead, we attribute the apparent hypertension of the knockout line originally described to comparison with a seemingly hypotensive transgenic line (SBP 103.7 ± 5.0 mmHg; DBP 71.9 ± 3.7 mmHg). Additionally, we quantified myocardial GPR37L1 transcript in humans, which was suggested to be downregulated in cardiovascular disease. We found that GPR37L1 has very low native transcript levels in human myocardium and that expression is not different in tissue samples from patients with heart failure compared with sex-matched healthy control tissue. These findings indicate that cardiac GPR37L1 expression is unlikely to contribute to the pathophysiology of human heart failure.NEW & NOTEWORTHY This study characterizes systolic blood pressure (SBP) in a Gpr37l1 knockout mouse line, which was previously reported to have ∼60 mmHg higher SBP compared with a transgenic line. We observed only a ∼27 mmHg SBP difference between the lines. However, when compared with C57BL/6J mice, knockout mice showed no difference in SBP. We also investigated GPR37L1 mRNA abundance in human hearts and observed no difference between healthy and failing heart samples.

Effect of high-intensity interval training on cardiometabolic component risks in persons with paraplegia: Protocol for a randomized controlled trial.

Individuals with a spinal cord injury (SCI) are at an increased risk of developing cardiovascular disease and present with a multitude of elevated cardiometabolic component risks. Although upper-body exercise appears an effective strategy to improve some of these outcomes, the effectiveness of high-intensity interval training (HIIT) has yet to be determined for this population. Therefore, a randomized controlled trial will be conducted to determine the effectiveness of a 6 week home-based upper-body HIIT intervention on biomarkers of cardiometabolic health in persons with spinal cord injury, in comparison to a control (CON) group. We will recruit 40 individuals with chronic (>1 year post-injury) paraplegia (spinal cord lesion between the second thoracic and second lumbar vertebrae), aged between 18 and 65 years. After baseline testing, participants will be assigned randomly, using a 2:1 allocation, to the home-based exercise intervention (HIIT, n = 26) or control group (CON, n = 14). The HIIT intervention will consist of 30 min of arm crank-based HIIT (60 s intervals at 80-90% peak heart rate) four times per week. Participants in the CON group will be asked to maintain their habitual diet and physical activity patterns over the study period. Baseline and follow-up assessments will be made for determination of body composition, postprandial glycaemic control, fasting blood lipids and systemic inflammation, aerobic capacity, physical activity and energy intake, resting metabolic rate, resting blood pressure, and subjective measures of health and well-being. ClinicalTrials.gov, ID: NCT04397250. Registered on 21 May 2020.

Viability of high intensity interval training in persons with spinal cord injury-a perspective review.

Spinal cord injury (SCI) leads to loss of sensory and motor function below the level of injury leading to paralysis and limitations to locomotion. Therefore, persons with SCI face various challenges in engaging in regular physical activity, which leads to a reduction in physical fitness, increases in body fat mass, and reduced physical and mental health status. Moderate intensity continuous training (MICT) is recommended to enhance physical fitness and overall health status in this population, but it is not always effective in promoting these benefits. High intensity interval training (HIIT) has been promoted as an alternative to MICT in individuals with SCI due to its documented efficacy in healthy able-bodied individuals as well as those with chronic disease. However, the body of knowledge concerning its application in this population is limited and mostly composed of studies with small and homogeneous samples. The aim of this review was to summarize the existing literature regarding the efficacy of HIIT on changes in health- and fitness-related outcomes in this population, denote potential adverse responses to HIIT, describe how participants perceive this modality of exercise training, and identify the overall feasibility of interval training in persons with SCI.

Physiological responses to moderate intensity continuous and high-intensity interval exercise in persons with paraplegia.

STUDY DESIGN: Randomized crossover. OBJECTIVES: To test differences in the duration and magnitude of physiological response to isocaloric moderate intensity continuous (MICE) and high-intensity interval exercise (HIIE) sessions in persons with spinal cord injury (SCI). SETTING: Academic medical center in Miami, FL, USA. METHODS: Ten adult men (mean ± s.d.; 39 ± 10 year old) with chronic (13.2 ± 8.8 year) paraplegia (T2-T10) completed a graded exercise test. Then, in a randomized order, participants completed MICE and HIIE for a cost of 120 kcal. MICE was performed at 24.6% POpeak. During HIIE, exercise was completed in 2 min work and recovery phases at 70%:10% POpeak. RESULTS: MICE and HIIE were isocaloric (115.9 ± 21.8 and 116.6 ± 35.0 kcal, respectively; p = 0.903), but differed in duration (39.8 ± 4.6 vs 32.2 ± 6.2 min; p < 0.001) and average respiratory exchange ratio (RER; 0.90 ± 0.08 vs 1.01 ± 0.07; p = 0.002). During MICE, a workrate of 24.6 ± 6.7% POpeak elicited a V̇O2 of 53.1 ± 6.5% V̇O2peak (10.1 ± 2.2 ml kg-1 min-1). During HIIE, a workrate at 70% POpeak elicited 88.3 ± 6.7% V̇O2peak (16.9 ± 4.2 ml kg-1 min-1), and 29.4 ± 7.7% of the session was spent at or above 80% V̇O2peak. During HIIE working phase, RER declined from the first to last interval (1.08 ± 0.07 vs 0.98 ± 0.09; p < 0.001), reflecting an initially high but declining glycolytic rate. CONCLUSIONS: Compared with MICE, HIIE imposed a greater physiological stimulus while requiring less time to achieve a target caloric expenditure. Thus, exercise intensity might be an important consideration in the tailoring of exercise prescription to address the cardiometabolic comorbidities of SCI.

A 7-day high-fat, high-calorie diet induces fibre-specific increases in intramuscular triglyceride and perilipin protein expression in human skeletal muscle.

KEY POINTS: We have recently shown that a high-fat, high-calorie (HFHC) diet decreases whole body glucose clearance without impairing skeletal muscle insulin signalling, in healthy lean individuals. These diets are also known to increase skeletal muscle IMTG stores, but the effect on lipid metabolites leading to skeletal muscle insulin resistance has not been investigated. This study measured the effect of 7 days' HFHC diet on (1) skeletal muscle concentration of lipid metabolites, and (2) potential changes in the perilipin (PLIN) content of the lipid droplets storing intramuscular triglyceride (IMTG). The HFHC diet increased PLIN3 protein expression and redistributed PLIN2 to lipid droplet stores in type I fibres. The HFHC diet increased IMTG content in type I fibres, while lipid metabolite concentrations remained the same. The data suggest that the increases in IMTG stores assists in reducing the accumulation of lipid metabolites known to contribute to skeletal muscle insulin resistance. ABSTRACT: A high-fat, high-calorie (HFHC) diet reduces whole body glucose clearance without impairing skeletal muscle insulin signalling in healthy lean individuals. HFHC diets also increase skeletal muscle lipid stores. However, unlike certain lipid metabolites, intramuscular triglyceride (IMTG) stored within lipid droplets (LDs) does not directly contribute to skeletal muscle insulin resistance. Increased expression of perilipin (PLIN) proteins and colocalisation to LDs has been shown to assist in IMTG storage. We aimed to test the hypothesis that 7 days on a HFHC diet increases IMTG content while minimising accumulation of lipid metabolites known to disrupt skeletal muscle insulin signalling in sedentary and obese individuals. We also aimed to identify changes in expression and subcellular distribution of proteins involved in IMTG storage. Muscle biopsies were obtained from the m. vastus lateralis of 13 (11 males, 2 females) healthy lean individuals (age: 23 ± 2.5 years; body mass index: 24.5 ± 2.4 kg m-2 ), following an overnight fast, before and after consuming a high-fat (64% energy), high-calorie (+47% kcal) diet for 7 days. After the HFHC diet, IMTG content increased in type I fibres only (+101%; P < 0.001), whereas there was no change in the concentration of either total diacylglycerol (P = 0.123) or total ceramides (P = 0.150). Of the PLINs investigated, only PLIN3 content increased (+50%; P < 0.01) solely in type I fibres. LDs labelled with PLIN2 increased (+80%; P < 0.01), also in type I fibres only. We propose that these adaptations of LDs support IMTG storage and minimise accumulation of lipid metabolites to protect skeletal muscle insulin signalling following 7 days' HFHC diet.

Viscous placebo and carbohydrate breakfasts similarly decrease appetite and increase resistance exercise performance compared with a control breakfast in trained males.

Given the common view that pre-exercise nutrition/breakfast is important for performance, the present study investigated whether breakfast influences resistance exercise performance via a physiological or psychological effect. Twenty-two resistance-trained, breakfast-consuming men completed three experimental trials, consuming water-only (WAT), or semi-solid breakfasts containing 0 g/kg (PLA) or 1·5 g/kg (CHO) maltodextrin. PLA and CHO meals contained xanthan gum and low-energy flavouring (approximately 122 kJ), and subjects were told both 'contained energy'. At 2 h post-meal, subjects completed four sets of back squat and bench press to failure at 90 % ten repetition maximum. Blood samples were taken pre-meal, 45 min and 105 min post-meal to measure serum/plasma glucose, insulin, ghrelin, glucagon-like peptide-1 and peptide tyrosine-tyrosine concentrations. Subjective hunger/fullness was also measured. Total back squat repetitions were greater in CHO (44 (sd 10) repetitions) and PLA (43 (sd 10) repetitions) than WAT (38 (sd 10) repetitions; P < 0·001). Total bench press repetitions were similar between trials (WAT 37 (sd 7) repetitions; CHO 39 (sd 7) repetitions; PLA 38 (sd 7) repetitions; P = 0·130). Performance was similar between CHO and PLA trials. Hunger was suppressed and fullness increased similarly in PLA and CHO, relative to WAT (P < 0·001). During CHO, plasma glucose was elevated at 45 min (P < 0·05), whilst serum insulin was elevated (P < 0·05) and plasma ghrelin suppressed at 45 and 105 min (P < 0·05). These results suggest that breakfast/pre-exercise nutrition enhances resistance exercise performance via a psychological effect, although a potential mediating role of hunger cannot be discounted.

Effect of Exercise on Cardiometabolic Risk Factors in Adults With Chronic Spinal Cord Injury: A Systematic Review.

OBJECTIVE: To determine the effects of exercise on individual cardiometabolic syndrome (CMS) risk factors in adults with chronic spinal cord injury (SCI). DATA SOURCES: English language searches of PubMed, Web of Science, EMBASE, and Scopus (January 1, 1970, to July 31, 2019). STUDY SELECTION: Articles were included if they met the following criteria: (1) original articles with statistical analysis, (2) participants were adults with a SCI sustained ≥1 year ago, (3) exercise intervention duration ≥2 weeks, and (4) included any CMS risk factor as an outcome. DATA EXTRACTION: The methodological quality of articles was assessed using the Downs and Black score. DATA SYNTHESIS: Sixty-five studies were included for the final analysis, including 9 studies classified as high quality (≥66.7%), 35 studies classified as fair quality (50%-66.6%), and 21 studies classified as low quality (<50%). Improvements in waist circumference (4/6 studies) and markers of hepatic insulin sensitivity (4/5 studies) were reported following upper body aerobic exercise training, but no improvements in fasting glucose (8/8 studies), lipid profile (6/8 studies), systolic blood pressure (8/9 studies), or diastolic blood pressure (9/9 studies) were observed. Improvements in markers of peripheral insulin sensitivity (5/6 studies) were observed following functional electrical stimulation (FES) cycling. Improvements in lipid profile (4/5 studies) were observed following upper body resistance training (RT) (with or without aerobic exercise). No consistent improvements in CMS risk factors were observed following assisted ambulation, FES hybrid, FES rowing, and FES RT. CONCLUSIONS: Upper body aerobic exercise training (>75% maximum heart rate) appears to improve waist circumference and hepatic insulin sensitivity but appears insufficient for improving fasting glucose, lipid profile, or resting blood pressure. The addition of RT to upper body aerobic exercise may elicit favorable changes in the lipid profile. More high-quality studies are needed to confirm if FES cycling is effective at improving peripheral insulin sensitivity.

The influence of expected satiety on portion size selection is reduced when food is presented in an 'unusual' meal context.

Research shows that expected satiety is highly correlated with ideal portion size, however this correspondence has not been explored when a food is presented in an 'unusual' (incongruous) meal context. This study's aim was to explore whether expected satiety influences portion selection to the same extent in both congruous and incongruous meal contexts. Forty participants completed two trials (one at breakfast and one at lunch) on separate days in a randomised counterbalanced order. They completed measures of expected satiety and ideal portion size for four typical breakfast foods and four typical lunch foods, using a bespoke computer program. Our results showed a significant difference between expected satiety and ideal portion size for lunch foods presented at breakfast time (an incongruous meal context; t(39) = 2.95, p = 0.02). There was no significant difference between expected satiety and ideal portion size in the other incongruous meal context (breakfast foods at lunch; t(39) = 2.10, p = 0.17) or in congruous meal contexts (breakfast foods at breakfast time, lunch foods at lunch time; both t(39) ≤ -0.15, p > 0.999). These results suggest that expected satiety does not have as strong an influence on portion selection when food is presented in an unusual context. Furthermore, in such contexts, smaller portions were selected 1) to stave off hunger until the next meal and 2) as ideal portions compared to in more usual meal contexts. Research is warranted to explore this finding further to understand its implications for weight management.

Eating rate and food intake are reduced when a food is presented in an 'unusual' meal context.

Research has shown that 1) the slower a food is eaten the less food is consumed overall, and 2) context affects portion selection. This study aimed to explore whether eating rate and food intake are influenced by consuming food in 'usual' vs 'unusual' mealtime contexts. Furthermore, this study aimed to identify whether mealtime-specific appropriateness and previous consumption frequency corresponded with differences in eating rate and food intake between contexts. Seventy-eight participants were served either cheese and tomato pasta (a typical lunch food) or porridge with milk and honey (a typical breakfast food) ad libitum at both breakfast and lunch on separate days. Results showed that eating rate was slower (60.7 vs 71.2 g/min, p < 0.001) and less food was consumed (404.1 vs 543.2 g, p < 0.001) when participants ate cheese and tomato pasta at breakfast compared to at lunch. However, no significant differences in eating rate (54.6 vs 56.4 g/min, p = 0.75) or food intake (423.7 vs 437.7 g, p = 0.88) were found between mealtimes for porridge with milk and honey. Furthermore, differences in eating rate and food intake between contexts were not associated with differences in mealtime-specific appropriateness or previous consumption frequency. These results suggest that eating rate and ad libitum food intake are influenced by the congruency of the food-to-mealtime context; however, this effect is not associated with mealtime-specific appropriateness or previous consumption of the food. Further research should explore the implications of introducing foods at unusual mealtimes in relation to strategies for weight management.

Orphan receptor ligand discovery by pickpocketing pharmacological neighbors.

Understanding the pharmacological similarity of G protein-coupled receptors (GPCRs) is paramount for predicting ligand off-target effects, drug repurposing, and ligand discovery for orphan receptors. Phylogenetic relationships do not always correctly capture pharmacological similarity. Previous family-wide attempts to define pharmacological relationships were based on three-dimensional structures and/or known receptor-ligand pairings, both unavailable for orphan GPCRs. Here, we present GPCR-CoINPocket, a novel contact-informed neighboring pocket metric of GPCR binding-site similarity that is informed by patterns of ligand-residue interactions observed in crystallographically characterized GPCRs. GPCR-CoINPocket is applicable to receptors with unknown structure or ligands and accurately captures known pharmacological relationships between GPCRs, even those undetected by phylogeny. When applied to orphan receptor GPR37L1, GPCR-CoINPocket identified its pharmacological neighbors, and transfer of their pharmacology aided in discovery of the first surrogate ligands for this orphan with a 30% success rate. Although primarily designed for GPCRs, the method is easily transferable to other protein families.