Effects of pre-meal whey protein consumption on acute food intake and energy balance over a 48-hour period

The effects of pre-meal whey protein consumption on acute food intake and subsequent energy balance measured over 48-h was investigated in males of healthy-weight (HW) or living with overweight and obesity (OV/OB). On two separate trial days, following a controlled breakfast (09:00) and lunch (13:00), 12 HW and 12 OV/OB males consumed either whey protein (20 g) or flavoured water beverages (16:40), and ad libitum test meal (17:00). A controlled 48-h assessment of energy intake and expenditure was used to determine any compensatory behaviour. Test meal energy intake reduced 15.9 % in HW (P = 0.003), and 17.8 % in OV/OB (P = 0.005) following whey protein, compared to placebo. We report no between-group differences and no changes in compensatory behaviour. A small dose of whey protein reduces energy intake at the next meal, without upregulating compensatory behaviours in both HW and OV/OB males. However, chronic effects on body composition and weight loss remain to be elucidated

Study protocol: a randomised controlled trial investigating the effect of exercise training on peripheral blood gene expression in patients with stable angina

Background: Exercise training has been shown to reduce angina and promote collateral vessel development in patients with coronary artery disease. However, the mechanism whereby exercise exerts these beneficial effects is unclear. There has been increasing interest in the use of whole genome peripheral blood gene expression in a wide range of conditions to attempt to identify both novel mechanisms of disease and transcriptional biomarkers. This protocol describes a study in which we will assess the effect of a structured exercise programme on peripheral blood gene expression in patients with stable angina, and correlate this with changes in angina level, anxiety, depression, and exercise capacity. Methods/Design: Sixty patients with stable angina will be recruited and randomised 1: 1 to exercise training or conventional care. Patients randomised to exercise training will attend an exercise physiology laboratory up to three times weekly for supervised aerobic interval training sessions of one hour in total duration. Patients will undergo assessments of angina, anxiety, depression, and peripheral blood gene expression at baseline, after six and twelve weeks of training, and twelve weeks after formal exercise training ceases. Discussion: This study will provide comprehensive data on the effect of exercise training on peripheral blood gene expression in patients with angina. By correlating this with improvement in angina status we will identify candidate peripheral blood transcriptional markers predictive of improvements in angina level in response to exercise training

High-intensity interval training and moderate-intensity continuous training in adults with Crohn’s disease: a pilot randomised controlled trial

Background: This study assessed the feasibility and acceptability of two common types of exercise training—high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT)—in adults with Crohn’s disease (CD). Methods: In this mixed-methods pilot trial, participants with quiescent or mildly-active CD were randomly assigned 1:1:1 to HIIT, MICT or usual care control, and followed up for 6 months. The HIIT and MICT groups were offered three exercise sessions per week for the first 12 weeks. Feasibility outcomes included rates of recruitment, retention, outcome completion, and exercise attendance. Data were collected on cardiorespiratory fitness (e.g., peak oxygen uptake), disease activity, fatigue, quality of life, adverse events, and intervention acceptability (via interviews). Results: Over 17 months, 53 patients were assessed for eligibility and 36 (68%) were randomised (47% male; mean age 36.9 [SD 11.2] years); 13 to HIIT, 12 to MICT, and 11 to control. The exercise session attendance rate was 62% for HIIT (288/465) and 75% for MICT (320/429), with 62% of HIIT participants (8/13) and 67% of MICT participants (8/12) completing at least 24 of 36 sessions. One participant was lost to follow-up. Outcome completion rates ranged from 89 to 97%. The mean increase in peak oxygen uptake, relative to control, was greater following HIIT than MICT (2.4 vs. 0.7 mL/kg/min). There were three non-serious exercise-related adverse events, and two exercise participants experienced disease relapse during follow-up. Conclusions: The findings support the feasibility and acceptability of the exercise programmes and trial procedures. A definitive trial is warranted. Physical exercise remains a potentially useful adjunct therapy in CD

Factors associated with regular physical activity participation among people with severe mental ill health

Purpose People with severe mental ill health (SMI) are less physically active and more sedentary than the general population. There is limited research investigating the correlates of physical activity (PA) in people with SMI impeding development of successful interventions. This study aimed to assess the factors associated with regular participation of PA among a large sample of people with SMI. Methods The data for this study were collected from the ‘Lifestyle Health and Wellbeing’ (HWB) cohort that collected data through self-administered questionnaire from participants with SMI. Self-reported participation in regular PA was the main outcome variable. Potential predictors of PA were grouped as demographic, biological, psychological and behavioural variables. Multivariable logistic regressions were conducted considering PA participation as the dependent variable adjusted for possible correlated predictors. Results In total, 3,287 people with SMI (mean (SD) age 47.7 (14.58) years, 59% male) were included; 38% reported undertaking regular PA and 61% wanted to undertake more physical activity. Multivariable logistic regressions showed that the following factors were associated with undertaking more regular PA: being male, aged 18-65 years, having a body mass index between 18.5 and 30 kg/m2, having better self-perceived general health condition, not having a health problem that limits activity, giving higher importance to maintain a healthy lifestyle, and eating more fruit and vegetables. Conclusions Having a better self-perceived general health and placing importance on maintaining a healthy lifestyle were important predictors of regular PA. Lifestyle interventions targeting increased PA among people with SMI should be shaped by their health perception and informed by their needs

A higher effort-based paradigm in physical activity and exercise for public health: making the case for a greater emphasis on resistance training

It is well known that physical activity and exercise is associated with a lower risk of a range of morbidities and all-cause mortality. Further, it appears that risk reductions are greater when physical activity and/or exercise is performed at a higher intensity of effort. Why this may be the case is perhaps explained by the accumulating evidence linking physical fitness and performance outcomes (e.g. cardiorespiratory fitness, strength, and muscle mass) also to morbidity and mortality risk. Current guidelines about the performance of moderate/vigorous physical activity using aerobic exercise modes focuses upon the accumulation of a minimum volume of physical activity and/or exercise, and have thus far produced disappointing outcomes. As such there has been increased interest in the use of higher effort physical activity and exercise as being potentially more efficacious. Though there is currently debate as to the effectiveness of public health prescription based around higher effort physical activity and exercise, most discussion around this has focused upon modes considered to be traditionally ‘aerobic’ (e.g. running, cycling, rowing, swimming etc.). A mode customarily performed to a relatively high intensity of effort that we believe has been overlooked is resistance training. Current guidelines do include recommendations to engage in ‘muscle strengthening activities’ though there has been very little emphasis upon these modes in either research or public health effort. As such the purpose of this debate article is to discuss the emerging higher effort paradigm in physical activity and exercise for public health and to make a case for why there should be a greater emphasis placed upon resistance training as a mode in this paradigm shift

Randomized feasibility trial of high-intensity interval training before elective abdominal aortic aneurysm repair

Background This study assessed the feasibility of a preoperative high-intensity interval training (HIT) programme in patients awaiting elective abdominal aortic aneurysm repair. Methods In this feasibility trial, participants were allocated by minimization to preoperative HIT or usual care. Patients in the HIT group were offered three exercise sessions per week for 4 weeks, and weekly maintenance sessions if surgery was delayed. Feasibility and acceptability outcomes were: rates of screening, eligibility, recruitment, retention, outcome completion, adverse events and adherence to exercise. Data on exercise enjoyment (Physical Activity Enjoyment Scale, PACES), cardiorespiratory fitness (anaerobic threshold and peak oxygen uptake), quality of life, postoperative morbidity and mortality, duration of hospital stay and healthcare utilization were also collected. Results Twenty-seven patients were allocated to HIT and 26 to usual care (controls). Screening, eligibility, recruitment, retention and outcome completion rates were 100 per cent (556 of 556), 43·2 per cent (240 of 556), 22·1 per cent (53 of 240), 91 per cent (48 of 53) and 79–92 per cent respectively. The overall exercise session attendance rate was 75·8 per cent (276 of 364), and the mean(s.d.) PACES score after the programme was 98(19) (‘enjoyable’); however, the intensity of exercise was generally lower than intended. The mean anaerobic threshold after exercise training (adjusted for baseline score and minimization variables) was 11·7 ml per kg per min in the exercise group and 11·4 ml per kg per min in controls (difference 0·3 (95 per cent c.i. –0·4 to 1·1) ml per kg per min). There were trivial-to-small differences in postoperative clinical and patient-reported outcomes between the exercise and control groups. Conclusion Despite the intensity of exercise being generally lower than intended, the findings support the feasibility and acceptability of both preoperative HIT and the trial procedures. A definitive trial is warranted. Registration number: ISRCTN09433624 (https://www.isrctn.com/)

Skin blood flow differentially affects near-infrared spectroscopy-derived measures of muscle oxygen saturation and blood volume at rest and during dynamic leg exercise.

The impact of skin blood flow changes on near-infrared spectroscopy (NIRS)-derived measures of muscle oxygen saturation (SmO2) and blood volume has not been fully established. We measured SmO2 and total hemoglobin concentration ([tHb]) responses of the right vastus lateralis during rest and dynamic knee extension exercise in ten young, healthy males. The protocol was repeated four times: twice without thigh heating for reliability, and twice with different grades of thigh heating for assessing the impact of cutaneous vasodilation on SmO2 and Δ[tHb]. The reliability of our SmO2 and [tHb] measurements was good. Thigh heating at 37 and 42°C caused marked increases in cutaneous vascular conductance (CVC) during rest and exercise (P 0.05 at all time points). In contrast, heating-induced increases in %CVCpeak were accompanied by increases in [tHb] at rest and during exercise and a decrease in Δ[tHb] during exercise (all P < 0.05). Our findings suggest that NIRS-derived measures of SmO2 and blood volume are differentially affected by skin blood flow at rest and during exercise. The findings from this study should be considered in NIRS experiments where skin blood flow can change markedly (e.g. high-intensity and/or prolonged exercise)