Calorie restriction-induced leptin reduction and T-lymphocyte activation in blood and adipose tissue in men with overweight and obesity.

BACKGROUND: T-Lymphocyte activation is modulated by the adipokine leptin and serum concentrations of this hormone can be reduced with short-term calorie restriction. The aim of this study was to understand whether leptin per se is important in determining levels of T-lymphocyte activation in humans, by investigating whether the reduction in leptin concentration following calorie restriction is associated with a decrease in T-Lymphocyte activation in blood and adipose tissue. METHODS: Twelve men with overweight and obesity (age 35-55 years, waist circumference 95-115 cm) reduced their calorie intake by 50% for 3 consecutive days. Blood and subcutaneous adipose tissue were obtained for isolation of immune cells and cytokine analysis. CD4+ and CD8 + T-Lymphocytes were identified and characterised according to their expression of activation markers CD25 and CD69 by flow cytometry. RESULTS: Serum leptin was reduced by (mean ± SEM) 31 ± 16% (p < 0.001) following calorie restriction. The percentage of blood CD4 + CD25 + T-lymphocytes and level of CD25 expression on these lymphocytes were significantly reduced by 8 ± 10% (p = 0.016) and 8 ± 4% (p = 0.058), respectively. After calorie restriction, ex vivo leptin secretion from abdominal subcutaneous adipose tissue explants was not changed, and this corresponded with a lack of change in adipose tissue resident T-Lymphocyte activation. CONCLUSIONS: Serum leptin was reduced after calorie restriction and this was temporally associated with a reduction in activation of blood CD4 + CD25 + T-Lymphocytes. In abdominal subcutaneous adipose tissue, however, leptin secretion was unaltered, and there were no observed changes in adipose resident T-Lymphocyte activation.

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.

Myths and Methodologies: Standardisation in human physiology research-should we control the controllables?

The premise of research in human physiology is to explore a multifaceted system whilst identifying one or a few outcomes of interest. Therefore, the control of potentially confounding variables requires careful thought regarding the extent of control and complexity of standardisation. One common factor to control prior to testing is diet, as food and fluid provision may deviate from participants' habitual diets, yet a self-report and replication method can be flawed by under-reporting. Researchers may also need to consider standardisation of physical activity, whether it be through familiarisation trials, wash-out periods, or guidance on levels of physical activity to be achieved before trials. In terms of pharmacological agents, the ethical implications of standardisation require researchers to carefully consider how medications, caffeine consumption and oral contraceptive prescriptions may affect the study. For research in females, it should be considered whether standardisation between- or within-participants in regards to menstrual cycle phase is most relevant. The timing of measurements relative to various other daily events is relevant to all physiological research and so it can be important to standardise when measurements are made. This review summarises the areas of standardisation which we hope will be considered useful to anyone involved in human physiology research, including when and how one can apply standardisation to various contexts.

Current and emerging 3D visualization technologies in radiology.

As the field of three-dimensional (3D) visualization rapidly advances, how healthcare professionals perceive and interact with real and virtual objects becomes increasingly complex. Lack of clear vocabulary to navigate the changing landscape of 3D visualization hinders clinical and scientific advancement, particularly within the field of radiology. In this article, we provide foundational definitions and illustrative examples for 3D visualization in clinical care, with a focus on the pediatric patient population. We also describe how understanding 3D visualization tools enables better alignment of hardware and software products with intended use-cases, thereby maximizing impact for patients, families, and healthcare professionals.

Myths and Methodologies: Standardisation in Human Physiology Research-Should We Control the Controllables?

The premise of research in human physiology is to explore a multifaceted system whilst identifying one or a few outcomes of interest. Therefore, the control of potentially confounding variables requires careful thought regarding the extent of control and complexity of standardisation. One common factor to control prior to testing is diet, as food and fluid provision may deviate from participants' habitual diets, yet a self-report and replication method can be flawed by under-reporting. Researchers may also need to consider standardisation of physical activity, whether it be through familiarisation trials, wash-out periods, or guidance on levels of physical activity to be achieved before trials. In terms of pharmacological agents, the ethical implications of standardisation require researchers to carefully consider how medications, caffeine consumption and oral contraceptive prescriptions may affect the study. For research in females, it should be considered whether standardisation between- or within-participants in regards to menstrual cycle phase is most relevant. The timing of measurements relative to various other daily events is relevant to all physiological research and so it can be important to standardise when measurements are made. This review summarises the areas of standardisation which we hope will be considered useful to anyone involved in human physiology research, including when and how one can apply standardisation to various contexts.

Whey Protein-Enriched and Carbohydrate-Rich Breakfasts Attenuate Insulinemic Responses to an ad libitum Lunch Relative to Extended Morning Fasting: A Randomized Crossover Trial.

BACKGROUND: Typical breakfast foods are rich in carbohydrate, so they not only elevate blood glucose during the morning, but also elicit a second-meal effect that can attenuate blood glucose responses in the afternoon. OBJECTIVES: To determine whether a reduced-carbohydrate protein-enriched breakfast can elicit similar effects on glucose control later in the day but without hyperglycemia in the morning. METHODS: In a randomized crossover design, 12 healthy men and women (age 22 ± 2 y, BMI 24.1 ± 3.6 kg·m-2; Mean ± SD) completed 3 experimental conditions. In all conditions, participants consumed an ad libitum lunch at 1200 ± 1 h but differed in terms of whether they had fasted all morning (control) or had consumed a standardized porridge breakfast at 0900 ± 1 h (320 ± 50 kcal; prescribed relative to resting metabolic rate) that was either carbohydrate-rich (50 ± 10 g CHO) or protein-enriched (that is, isoenergetic substitution of carbohydrate for 15 g whey protein isolate). RESULTS: The protein-enriched breakfast reduced the morning glycemic response (iAUC 87 ± 36 mmol·L-1·180 min) relative to the carbohydrate-rich breakfast (119 ± 37 mmol·L-1·180 min; P = 0.03). Despite similar energy intake at lunch in all 3 conditions (protein-enriched 769 ± 278 kcal; carbohydrate-rich 753 ± 223 kcal; fasting 790 ± 227 kcal), postlunch insulinemic responses were markedly attenuated when breakfasts had been consumed that were either protein-enriched (18.0 ± 8.0 nmol·L-1·120 min; P = 0.05) or carbohydrate-rich (16.0 ± 7.7 nmol·L-1·120 min; P = 0.005), relative to when lunch was consumed in an overnight fasted state (26.9 ± 13.5 nmol·L-1·120 min). CONCLUSIONS: Breakfast consumption attenuates insulinemic responses to a subsequent meal, achieved with consumption of energy-matched breakfasts typically high in carbohydrates or enriched with whey protein isolate relative to extended morning fasting. TRIAL REGISTRATION NUMBER: NCT03866720 (clinicaltrials.gov).

Restricting sugar or carbohydrate intake does not impact physical activity level or energy intake over 24 h despite changes in substrate use: a randomised crossover study in healthy men and women.

PURPOSE: To determine the effects of dietary sugar or carbohydrate restriction on physical activity energy expenditure, energy intake, and physiological outcomes across 24 h. METHODS: In a randomized, open-label crossover design, twenty-five healthy men (n = 10) and women (n = 15) consumed three diets over a 24-h period: moderate carbohydrate and sugar content (MODSUG = 50% carbohydrate [20% sugars], 15% protein, 35% fat); low sugar content (LOWSUG = 50% carbohydrate [< 5% sugars], 15% protein, 35% fat); and low carbohydrate content (LOWCHO = 8% carbohydrate [< 5% sugars], 15% protein, 77% fat). Postprandial metabolic responses to a prescribed breakfast (20% EI) were monitored under laboratory conditions before an ad libitum test lunch, with subsequent diet and physical activity monitoring under free-living conditions until blood sample collection the following morning. RESULTS: The MODSUG, LOWSUG and LOWCHO diets resulted in similar mean [95%CI] rates of both physical activity energy expenditure (771 [624, 919] vs. 677 [565, 789] vs. 802 [614, 991] kcal·d-1; p = 0.29] and energy intake (2071 [1794, 2347] vs. 2195 [1918, 2473] vs. 2194 [1890, 2498] kcal·d-1; P = 0.34), respectively. The LOWCHO condition elicited the lowest glycaemic and insulinaemic responses to breakfast (P < 0.01) but the highest 24-h increase in LDL-cholesterol concentrations (P < 0.001), with no differences between the MODSUG and LOWSUG treatments. Leptin concentrations decreased over 24-h of consuming LOWCHO relative to LOWSUG (p < 0.01). CONCLUSION: When energy density is controlled for, restricting either sugar or total dietary carbohydrate does not modulate physical activity level or energy intake over a 24-h period (~ 19-h free-living) despite substantial metabolic changes. CLINICAL TRIALS REGISTRATION ID: NCT03509610, https://clinicaltrials.gov/show/NCT03509610.

Divergent immunometabolic changes in adipose tissue and skeletal muscle with ageing in healthy humans.

KEY POINTS: Ageing is associated with increased systemic inflammation and metabolic dysfunction that contributes to the development of age-associated diseases. The role of adipose tissue in immunometabolic alterations that take place with ageing is unknown in humans. We show, in healthy, active and lean older adults, that adipose tissue, but not skeletal muscle, displays considerable pro-inflammatory transcriptomic, cellular and secretory changes, as well as a reduction in insulin signalling proteins compared to younger adults. These findings indicate that adipose tissue undergoes substantial immunometabolic alterations with ageing, and that these changes are tissue-specific and more profound than those observed in skeletal muscle or in the circulation. These results identify adipose tissue as an important tissue in the biological ageing process in humans, which may exhibit signs of immunometabolic dysfunction prior to systemic manifestation. ABSTRACT: Ageing and obesity are both characterized by inflammation and a deterioration in metabolic health. It is now clear that adipose tissue plays a major role in inflammation and metabolic control in obesity, although little is known about the role of adipose tissue in human ageing. To understand how ageing impacts adipose tissue, we characterized subcutaneous adipose tissue and skeletal muscle samples from twelve younger (27 ± 4 years [Young]) and twelve older (66 ± 5 years [Old]) active/non-obese males. We performed a wide-range of whole-body and tissue measures, including RNA-sequencing and multicolour flow cytometry. We also measured a range of inflammatory and metabolic proteins in the circulation and their release by adipose tissue, ex vivo. Both adipose tissue and muscle had ∼2-fold more immune cells per gram of tissue with ageing. In adipose tissue, this immune cell infiltration was driven by increased memory/effector T-cells, whereas, in muscle, the accumulation was driven by memory/effector T-cells and macrophages. Transcriptomic analysis revealed that, with ageing, adipose tissue, but not muscle, was enriched for inflammatory transcripts/pathways related to acquired and innate immunity. Ageing also increased the adipose tissue pro-inflammatory secretory profile. Insulin signalling protein content was reduced in adipose tissue, but not muscle. Our findings indicate that adipose tissue undergoes substantial immunometabolic changes with ageing in humans, and that these changes are tissue-specific and more profound than those observed in the circulation and skeletal muscle.

Feasibility and Acceptability of Home-Based Exercise Snacking and Tai Chi Snacking Delivered Remotely to Self-Isolating Older Adults During COVID-19.

The purpose of this study was to examine the feasibility and acceptability of remotely delivered, home-based exercise programs on physical function and well-being in self-isolating older adults during the COVID-19 pandemic. In a four-arm randomized controlled trial, 63 participants (aged 65 years and older) were allocated to one of three home-based daily (2 × 10-min) exercise interventions (exercise snacking, tai chi snacking, and combination) or control (UK National Health Service Web pages). Functional assessments were conducted via video call at baseline and 4-week follow-up. A web-based survey assessed the acceptability of each exercise program and secondary psychological/well-being outcomes. Ecological momentary assessment data, collected in Weeks 1 and 4, explored feeling states as antecedents and consequences of exercise. All intervention groups saw increased physical function at follow-up and displayed good adherence with exercise snacking considered the most acceptable program. Multilevel models revealed reciprocal associations between feelings of energy and exercise engagement. Further studies are needed with larger, more diverse demographic 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.

The understanding, acceptability, and relevance of personalised multidimensional physical activity feedback among urban adults: evidence from a qualitative feasibility study in Sri Lanka.

BACKGROUND: Wearable technologies are being used to provide personalised feedback across multiple physical activity dimensions in countries such as the UK, but their feasibility has not been tested in South Asia, where physical inactivity is increasing. This study assessed the understanding, acceptability, and relevance of personalised multidimensional physical activity feedback in urban dwellers in Colombo, Sri Lanka. METHODS: A qualitative feasibility study was conducted among 35 adults to assess a community-based approach to provide multidimensional physical activity feedback. Healthy adults, adults at risk of non-communicable diseases and community-based primary healthcare professionals wore a physical activity monitor for 7 days and were then guided through their personalised multidimensional physical activity feedback. One-to-one interviews were conducted, transcribed verbatim and analysed using framework analysis. RESULTS: Four themes were generated: understanding of personalised physical activity feedback, perceived novelty of the feedback, motivation, and consideration of the multidimensional nature of physical activity. A majority of participants required guidance initially to understand the feedback, following which most were quickly able to interpret the data shown, and were willing to use the feedback as a basis for identifying goals to improve physical activity. Participants perceived the feedback and its delivery as novel because it provided new knowledge about physical activity guidelines and awareness on their own behaviour through graphics. Comparisons of personal performance against recommended physical activity levels and information on sedentary time were the most commonly motivating aspects of the feedback, prompting talk about behaviour change. All three groups showed poor planning on goal achievement, with some noticeable differences between those with and without health risk of non-communicable diseases. Following the feedback, most participants understood that physical activity is composed of several dimensions, while around half could recognise more suitable options to change behaviour. Of the physical activity dimensions, calorie burn received more attention than others. CONCLUSIONS: Multidimensional physical activity feedback was considered understandable and acceptable and has the potential to support behaviour change among urban Sri Lankans with or without identified health risk. These findings highlight the feasibility of this technology-enabled approach as a personalised intervention to improve knowledge and motivation for physical activity behaviour.

Galactose Ingested with a High-Fat Beverage Increases Postprandial Lipemia Compared with Glucose but Not Fructose Ingestion in Healthy Men.

BACKGROUND: Fructose ingestion with a high-fat beverage increases postprandial lipemia when compared with glucose. It is unknown whether other sugars, such as galactose, also increase postprandial lipemia. OBJECTIVES: The objective was to assess whether galactose ingestion within a high-fat beverage increases postprandial lipemia relative to glucose or fructose. METHODS: Two experiments were conducted, which contrasted different test drinks under otherwise standardized conditions. In Experiment 1, 10 nonobese men (age: 22 ± 1 y; BMI, 23.5 ± 2.2 kg/2) ingested either galactose or glucose (0.75 g supplemented carbohydrate per⋅kilogram body mass) within a high-fat test drink (0.94 g fat per kilogram body mass). In Experiment 2, a separate group of 9 nonobese men (age: 26 ± 6 y; BMI: 23.5 ± 2.6 kg/m2) ingested either galactose or fructose (identical doses as those in Experiment 1) within the same high-fat test drink. Capillary blood was sampled before and at frequent intervals after ingestion of the test drinks for a 300-min period to determine plasma triacylglycerol, glucose, lactate, nonesterified fatty acid, and insulin concentrations. Paired t tests and 2-way, repeated-measures ANOVA were used to compare conditions within each experiment. RESULTS: The incremental AUC for triacylglycerol was greater following galactose ingestion compared with glucose (127 ± 59 compared with 80 ± 48 mmol⋅L-1 × 300 min, respectively; P = 0.04) but not compared with fructose (136 ± 74 compared with 133 ± 63 mmol⋅L-1 ×300 min, respectively; P = 0.91). Plasma lactate concentrations also increased to a greater extent with galactose compared with glucose ingestion (time-condition interaction: P < 0.001) but not fructose ingestion (time-condition interaction: P = 0.17). CONCLUSIONS: Galactose ingestion within a high-fat beverage exacerbates postprandial lipemia and plasma lactate concentrations compared with glucose but not fructose in nonobese men. These data suggest that galactose metabolism may be more similar to fructose than to glucose, providing a rationale to reassess the metabolic fate of galactose ingestion in humans. This trial was registered at clinicaltrials.gov as NCT03439878.

Effect of novel technology-enabled multidimensional physical activity feedback in primary care patients at risk of chronic disease - the MIPACT study: a randomised controlled trial.

BACKGROUND: Technological progress has enabled the provision of personalised feedback across multiple dimensions of physical activity that are important for health. Whether this multidimensional approach supports physical activity behaviour change has not yet been examined. Our objective was to examine the effectiveness of a novel digital system and app that provided multidimensional physical activity feedback combined with health trainer support in primary care patients identified as at risk of chronic disease. METHODS: MIPACT was a parallel-group, randomised controlled trial that recruited patients at medium (≥10 and < 20%) or high (≥20%) risk of cardiovascular disease and/or type II diabetes from six primary care practices in the United Kingdom. Intervention group participants (n = 120) received personal multidimensional physical activity feedback using a customised digital system and web-app for 3 months plus five health trainer-led sessions. All participants received standardised information regarding physical activity. Control group participants (n = 84) received no further intervention. The primary outcome was device-based assessment of physical activity at 12 months. RESULTS: Mean intervention effects were: moderate-vigorous physical activity: -1.1 (95% CI, - 17.9 to 15.7) min/day; moderate-vigorous physical activity in ≥10-min bouts: 0.2 (- 14.2 to 14.6) min/day; Physical Activity Level (PAL): 0.00 (- 0.036 to 0.054); vigorous physical activity: 1.8 (- 0.8 to 4.2) min/day; and sedentary time: 10 (- 19.3 to 39.3) min/day. For all of these outcomes, the results showed that the groups were practically equivalent and statistically ruled out meaningful positive or negative effects (>minimum clinically important difference, MCID). However, there was profound physical activity multidimensionality, and only a small proportion (5%) of patients had consistently low physical activity across all dimensions. CONCLUSION: In patients at risk of cardiovascular disease and/or type II diabetes, MIPACT did not increase mean physical activity. Using a sophisticated multidimensional digital approach revealed enormous heterogeneity in baseline physical activity in primary care patients, and practitioners may need to screen for low physical activity across dimensions rather than rely on disease-risk algorithms that are heavily influenced by age. TRIAL REGISTRATION: This trial is registered with the ISRCTN registry ( ISRCTN18008011 ; registration date 31 July 2013).

Co-ingestion of whey protein hydrolysate with milk minerals rich in calcium potently stimulates glucagon-like peptide-1 secretion: an RCT in healthy adults.

PURPOSE: To examine whether calcium type and co-ingestion with protein alter gut hormone availability. METHODS: Healthy adults aged 26 ± 7 years (mean ± SD) completed three randomized, double-blind, crossover studies. In all studies, arterialized blood was sampled postprandially over 120 min to determine GLP-1, GIP and PYY responses, alongside appetite ratings, energy expenditure and blood pressure. In study 1 (n = 20), three treatments matched for total calcium content (1058 mg) were compared: calcium citrate (CALCITR); milk minerals rich in calcium (MILK MINERALS); and milk minerals rich in calcium plus co-ingestion of 50 g whey protein hydrolysate (MILK MINERALS + PROTEIN). In study 2 (n = 6), 50 g whey protein hydrolysate (PROTEIN) was compared to MILK MINERALS + PROTEIN. In study 3 (n = 6), MILK MINERALS was compared to the vehicle of ingestion (water plus sucralose; CONTROL). RESULTS: MILK MINERALS + PROTEIN increased GLP-1 incremental area under the curve (iAUC) by ~ ninefold (43.7 ± 11.1 pmol L-1 120 min; p < 0.001) versus both CALCITR and MILK MINERALS, with no difference detected between CALCITR (6.6 ± 3.7 pmol L-1 120 min) and MILK MINERALS (5.3 ± 3.5 pmol L-1 120 min; p > 0.999). MILK MINERALS + PROTEIN produced a GLP-1 iAUC ~ 25% greater than PROTEIN (p = 0.024; mean difference: 9.1 ± 6.9 pmol L-1 120 min), whereas the difference between MILK MINERALS versus CONTROL was small and non-significant (p = 0.098; mean difference: 4.2 ± 5.1 pmol L-1 120 min). CONCLUSIONS: When ingested alone, milk minerals rich in calcium do not increase GLP-1 secretion compared to calcium citrate. Co-ingesting high-dose whey protein hydrolysate with milk minerals rich in calcium increases postprandial GLP-1 concentrations to some of the highest physiological levels ever reported. Registered at ClinicalTrials.gov: NCT03232034, NCT03370484, NCT03370497.

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.

Effect of carbohydrate-protein supplementation on endurance training adaptations.

PURPOSE: To examine the influence of post-exercise protein feeding upon the adaptive response to endurance exercise training. METHODS: In a randomised parallel group design, 25 healthy men and women completed 6 weeks of endurance exercise training by running on a treadmill for 30-60 min at 70-75% maximal oxygen uptake (VO2max) 4 times/week. Participants ingested 1.6 g per kilogram of body mass (g kg BM-1) of carbohydrate (CHO) or an isocaloric carbohydrate-protein solution (CHO-P; 0.8 g carbohydrate kg BM-1 + 0.8 g protein kg BM-1) immediately and 1 h post-exercise. Expired gas, blood and muscle biopsy samples were taken at baseline and follow-up. RESULTS: Exercise training improved VO2max in both groups (p ≤ 0.001), but this increment was not different between groups either in absolute terms or relative to body mass (0.2 ± 0.2 L min-1 and 3.0 ± 2 mL kg-1 min-1, respectively). No change occurred in plasma albumin concentration from baseline to follow-up with CHO-P (4.18 ± 0.18 to 4.23 ± 0.17 g dL-1) or CHO (4.17 ± 0.17 to 4.12 ± 0.22 g dL-1; interaction: p > 0.05). Mechanistic target of rapamycin (mTOR) gene expression was up-regulated in CHO-P (+ 46%; p = 0.025) relative to CHO (+ 4%) following exercise training. CONCLUSION: Post-exercise protein supplementation up-regulated the expression of mTOR in skeletal muscle over 6 weeks of endurance exercise training. However, the magnitude of improvement in VO2max was similar between groups.

Physical activity and exercise in the regulation of human adipose tissue physiology.

Physical activity and exercise are key components of energy expenditure and therefore of energy balance. Changes in energy balance alter fat mass. It is therefore reasonable to ask: What are the links between physical activity and adipose tissue function? There are many complexities. Physical activity is a multifaceted behavior of which exercise is just one component. Physical activity influences adipose tissue both acutely and in the longer term. A single bout of exercise stimulates adipose tissue blood flow and fat mobilization, resulting in delivery of fatty acids to skeletal muscles at a rate well-matched to metabolic requirements, except perhaps in vigorous intensity exercise. The stimuli include adrenergic and other circulating factors. There is a period following an exercise bout when fatty acids are directed away from adipose tissue to other tissues such as skeletal muscle, reducing dietary fat storage in adipose. With chronic exercise (training), there are changes in adipose tissue physiology, particularly an enhanced fat mobilization during acute exercise. It is difficult, however, to distinguish chronic "structural" changes from those associated with the last exercise bout. In addition, it is difficult to distinguish between the effects of training per se and negative energy balance. Epidemiological observations support the idea that physically active people have relatively low fat mass, and intervention studies tend to show that exercise training reduces fat mass. A much-discussed effect of exercise versus calorie restriction in preferentially reducing visceral fat is not borne out by meta-analyses. We conclude that, in addition to the regulation of fat mass, physical activity may contribute to metabolic health through beneficial dynamic changes within adipose tissue in response to each activity bout.

Skipping Breakfast Before Exercise Creates a More Negative 24-hour Energy Balance: A Randomized Controlled Trial in Healthy Physically Active Young Men.

BACKGROUND: At rest, omission of breakfast lowers daily energy intake, but also lowers energy expenditure, attenuating any effect on energy balance. The effect of breakfast omission on energy balance when exercise is prescribed is unclear. OBJECTIVES: The aim of this study was to assess the effect on 24-h energy balance of omitting compared with consuming breakfast prior to exercise. METHODS: Twelve healthy physically active young men (age 23 ± 3 y, body mass index 23.6 ± 2.0 kg/m2) completed 3 trials in a randomized order (separated by >1 week): a breakfast of oats and milk (431 kcal; 65 g carbohydrate, 11 g fat, 19 g protein) followed by rest (BR); breakfast before exercise (BE; 60 min cycling at 50 % peak power output); and overnight fasting before exercise (FE). The 24-h energy intake was calculated based on the food consumed for breakfast, followed by an ad libitum lunch, snacks, and dinner. Indirect calorimetry with heart-rate accelerometry was used to measure substrate utilization and 24-h energy expenditure. A [6,6-2H2]glucose infusion was used to investigate tissue-specific carbohydrate utilization. RESULTS: The 24-h energy balance was -400 kcal (normalized 95% CI: -230, -571 kcal) for the FE trial; this was significantly lower than both the BR trial (492 kcal; normalized 95% CI: 332, 652 kcal) and the BE trial (7 kcal; normalized 95% CI: -153, 177 kcal; both P < 0.01 compared with FE). Plasma glucose utilization in FE (mainly representing liver glucose utilization) was positively correlated with energy intake compensation at lunch (r = 0.62, P = 0.03), suggesting liver carbohydrate plays a role in postexercise energy-balance regulation. CONCLUSIONS: Neither exercise energy expenditure nor restricted energy intake via breakfast omission were completely compensated for postexercise. In healthy men, pre-exercise breakfast omission creates a more negative daily energy balance and could therefore be a useful strategy to induce a short-term energy deficit. This trial was registered at clinicaltrials.gov as NCT02258399.

Carbohydrate Availability as a Regulator of Energy Balance With Exercise.

We explore the novel hypothesis that carbohydrate availability is involved in the regulation of energy balance with exercise, via hormonal and neural signals. We propose that carbohydrate availability could play a direct mechanistic role and partially explain previously documented relations between a more active lifestyle and tighter control of energy balance.

Effects of a Web-Based, Evolutionary Mismatch-Framed Intervention Targeting Physical Activity and Diet: a Randomised Controlled Trial.

BACKGROUND: This study sought to test the effectiveness of a 12-week, novel online intervention (Evolife) aiming to increase physical activity level (PAL) and reduce energy intake (EI) among overweight/obese adults. The intervention used an evolutionary mismatch message to frame health information in an engaging way, incorporating evidence-based behaviour change techniques to promote autonomous motivation, self-efficacy and self-regulatory skills. METHOD: Men and women aged 35-74 years with a BMI of 25-40 kg/m2 were eligible. Participants were randomised to receive either the intervention (comprising a face-to-face introductory session, 12 weeks' access to the Evolife website and a pedometer) or a control condition (face-to-face introductory session and NHS online health resources). PAL was measured objectively and EI was self-reported using 3-day weighed food records. Secondary measures included BMI, waist circumference and blood pressure. RESULTS: Sixty people met inclusion criteria; 59 (30 intervention) completed the trial (mean age = 50; 56% male). Differences between groups' change scores for PAL and EI were of small effect size but did not reach significance (d = 0.32 and d = - 0.49, respectively). Improvements were found in both groups for PAL (int: d = 0.33; control: d = 0.04), EI (int: d = - 0.81; control: d = - 0.16), waist circumference (int: d = - 0.30; control: d = - 0.17) and systolic blood pressure (int: d = - 0.67; control: d = - 0.28). CONCLUSION: The intervention did not lead to significantly greater improvement in PAL or reduction in EI than a minimal intervention control, although the changes in the intervention group were of meaningful effect size and comparable with positive outcomes in larger intervention trials. TRIAL REGISTRATION: This trail was registered on www.clinicaltrials.gov on 16 January 2017 (appeared online 26 January 2017), reference NCT03032731.