PL-009 Not just a one HIIT wonder: two popular HIIT protocols elicit similar health benefits in a controlled but real world environment

Objective Currently 40% of the UK do not meet the physical activity guidelines with a ‘lack of time’ the most commonly cited barrier to sufficient physical activity. In laboratory based training interventions, high intensity interval training (HIT) offers a time-efficient alternative to moderate intensity continuous training (MICT) but its success requires expensive specialised cycle ergometers and vigorous encouragement from the researchers. To investigate whether two popular HIT protocols, performed using readily available cycle ergometers and without encouragement, can improve aerobic exercise capacity, arterial stiffness and body composition. Methods Eighty-two sedentary males (n=26) and females (n=56) aged 18-65 participated in the study (28±1 y, BMI 25±0.4 kg.m-2). In a randomised cross-over design, participants completed either 6 weeks of 30HIT (4-8x30s sprint with 120s active recovery) or 60HIT (6-10x60s sprint with 60s active recovery). Training sessions were completed on a Wattbike, 3 times per week. VO2peak, body composition (DXA scan), blood glucose (oral glucose tolerance test (OGTT)) and arterial stiffness (pulse wave velocity (PWV)) were assessed pre and post each 6-week training phase, with 4-6 weeks washout period between interventions. Results VO2peakincreased post intervention in 30HIT (36±1 to 39±1 ml.min-1.kg-1) and 60HIT (36±1 to 39±1 ml.min-1.kg-1) (P<0.001), with no difference between intervention group (P=0.208). Body fat percentage decreased pre to post training in both conditions (P=0.001). PWV decreased in 30HIT (2%) and 60HIT (4%) (P<0.005). During the OGTT, there was a trend towards decreasing area under the curve pre to post (P=0.083). When normalized to Watt maxthe participants producing a higher mean power output improved their VO2peakmore than those producing a low MPO (P<0.05). Following further analysis this was only true in 60HIT (P<0.05). Conclusions Both 30HIT and 60HIT could be effective real world strategies to improve aerobic capacity, body composition, arterial stiffness and insulin sensitivity. Improvements were seen even though the time spent sprinting was less in 30HIT (4mins compared to 10mins in 60HIT). In addition, how the 30HIT protocol is executed does not seem to have an effect on physiological outcomes. This suggests 30HIT may be a more applicable training intervention in the real world

Passive Heat Therapy in Sedentary Humans Increases Skeletal Muscle Capillarisation and eNOS Content but Not Mitochondrial Density or GLUT4 Content.

Passive heat therapy (PHT) has been proposed as an alternative intervention to traditional moderate intensity continous training (MICT) in individuals who are unable or unwilling to exercise. This study aimed to make the first comparison of the effect of PHT and MICT on 1) skeletal muscle capillarisation and endothelial specific eNOS content and 2) mitochondrial density, GLUT4 and IMTG content. Twenty young sedentary males (21±1years, BMI 25±1kg.m-2) were allocated to either 6 weeks of PHT (n=10; 40-50min at 40°C in a heat chamber, 3x/wk) or MICT (n=10; time matched cycling at ~65% VO2peak). Muscle biopsies were taken from the vastus lateralis muscle pre- and post-training. Immunofluorescence microscopy was used to assess changes in skeletal muscle mitochondrial density, GLUT4 and IMTG content, capillarisation and endothelial specific eNOS content. VO2peak and whole body insulin sensitivity were also assessed. PHT and MICT both increased capillary density and capillary-fibre perimeter exchange index (P<0.05), and endothelial specific eNOS content (P<0.05). However, unlike MICT (P<0.05) PHT did not increase mitochondrial density (P=0.443), GLUT4 (P=0.217) or IMTG content (P=0.957). Both intervention improved aerobic capacity and whole body insulin sensitivity (P<0.05). 6 weeks PHT in young sedentary males increases skeletal muscle capillarisation and eNOS content to a similar extent as MICT, however, unlike MICT PHT does not affect skeletal muscle mitochondrial density, GLUT4 or IMTG content

Ex Vivo treatment of coronary artery endothelial cells with serum post-exercise training offers limited protection against in vitro exposure to FEC-T chemotherapy

Background: Chemotherapy treatment for breast cancer associates with well-documented cardiovascular detriments. Exercise has shown promise as a potentially protective intervention against cardiac toxicity. However, there is a paucity of evidence for the benefits of exercise on the vasculature. Objectives: This study aimed to determine the effects of chemotherapy on the vascular endothelium; and if there are protective effects of serological alterations elicited by an exercise training intervention. Methods and Results: 15 women participated in a 12-week home-based exercise intervention consisting of three high-intensity interval sessions per week. Human coronary artery endothelial cells (HCAEC) were exposed to physiological concentrations of 5-fluorouracil, epirubicin, cyclophosphamide (FEC) and docetaxel to determine a dose-response. Twenty-4 hours prior to FEC and docetaxel exposure, HCAECs were preconditioned with serum collected pre- and post-training. Annexin V binding and cleaved caspase-3 were assessed using flow cytometry and wound repair by scratch assays. Chemotherapy exposure increased HCAEC Annexin V binding, cleaved caspase-3 expression in a dose-dependent manner; and inhibited wound repair. Compared to pre-training serum, conditioning HCAECs with post-training serum, reduced Annexin V binding (42% vs. 30%, p = 0.01) when exposed to FEC. For docetaxel, there were no within-group differences (pre-vs post-exercise) for Annexin V binding or cleaved caspase-3 expression. There was a protective effect of post-training serum on wound repair for 5-flurouracil (p = 0.03) only. Conclusion: FEC-T chemotherapy drugs cause significant damage and dysfunction of endothelial cells. Preconditioning with serum collected after an exercise training intervention, elicited some protection against the usual toxicity of FEC-T, when compared to control serum

Ex Vivo treatment of coronary artery endothelial cells with serum post-exercise training offers limited protection against in vitro exposure to FEC-T chemotherapy

Background: Chemotherapy treatment for breast cancer associates with well-documented cardiovascular detriments. Exercise has shown promise as a potentially protective intervention against cardiac toxicity. However, there is a paucity of evidence for the benefits of exercise on the vasculature. Objectives: This study aimed to determine the effects of chemotherapy on the vascular endothelium; and if there are protective effects of serological alterations elicited by an exercise training intervention. Methods and Results: 15 women participated in a 12-week home-based exercise intervention consisting of three high-intensity interval sessions per week. Human coronary artery endothelial cells (HCAEC) were exposed to physiological concentrations of 5-fluorouracil, epirubicin, cyclophosphamide (FEC) and docetaxel to determine a dose-response. Twenty-4 hours prior to FEC and docetaxel exposure, HCAECs were preconditioned with serum collected pre- and post-training. Annexin V binding and cleaved caspase-3 were assessed using flow cytometry and wound repair by scratch assays. Chemotherapy exposure increased HCAEC Annexin V binding, cleaved caspase-3 expression in a dose-dependent manner; and inhibited wound repair. Compared to pre-training serum, conditioning HCAECs with post-training serum, reduced Annexin V binding (42% vs. 30%, p = 0.01) when exposed to FEC. For docetaxel, there were no within-group differences (pre-vs post-exercise) for Annexin V binding or cleaved caspase-3 expression. There was a protective effect of post-training serum on wound repair for 5-flurouracil (p = 0.03) only. Conclusion: FEC-T chemotherapy drugs cause significant damage and dysfunction of endothelial cells. Preconditioning with serum collected after an exercise training intervention, elicited some protection against the usual toxicity of FEC-T, when compared to control serum

Remote maintenance cardiac rehabilitation (MAINTAIN)::A protocol for a randomised feasibility study

Background: Long-term adherence to exercise is often poor for people with coronary heart disease (CHD) who have completed supervised, centre-based cardiac rehabilitation. The aim of this study is to assess the feasibility of a remotely prescribed, delivered and monitored cardiac rehabilitation intervention using a wearable device to support long-term adherence to exercise and physical activity during maintenance of cardiac rehabilitation. Methods: After completing cardiac rehabilitation, 30 participants with CHD, will be randomised (1:1) to an intervention (n = 15) or a usual care group (n = 15) in a 12-month feasibility randomised controlled trial (RCT). The intervention will comprise of an exercise consultation, personalised exercise prescription delivered via a wearable activity monitor using biometric feedback, regular monitoring via check-ins, and feedback text-messages for 6-months. Participants will be assessed at baseline (following completion of cardiac rehabilitation) and at three-, six-, and 12-months post-randomisation. The primary outcome will be feasibility, including assessment of eligibility, recruitment, adherence, and acceptability. Secondary outcomes will include exercise capacity, physical activity behaviours, cardiovascular disease risk and quality of life. Semi-structured interviews will be conducted at three-, six-, and 12-months post-randomisation (and with those who drop-out) to explore the acceptability of the study intervention and procedures. A questionnaire will be offered to those who decline participation. Discussion: The MAINTAIN study will evaluate the feasibility of conducting a future definitive multi-centre RCT testing a remotely prescribed and monitored long-term mHealth maintenance exercise programme, versus usual care, for people with CHD who have completed cardiac rehabilitation. Trial registration number: ClinicalTrials.gov, NCT05292287. Registered on 22/03/202

Alien pathogens on the horizon: opportunities for predicting their threat to wildlife

According to the Convention on Biological Diversity, by 2020 invasive alien species (IAS) should be identified and their impacts assessed, so that species can be prioritized for implementation of appropriate control strategies and measures put in place to manage invasion pathways. For one quarter of the IAS listed as the “100 of the world's worst” environmental impacts are linked to diseases of wildlife (undomesticated plants and animals). Moreover, IAS are a significant source of “pathogen pollution” defined as the human-mediated introduction of a pathogen to a new host or region. Despite this, little is known about the biology of alien pathogens and their biodiversity impacts after introduction into new regions. We argue that the threats posed by alien pathogens to endangered species, ecosystems, and ecosystem services should receive greater attention through legislation, policy, and management. We identify 10 key areas for research and action, including those relevant to the processes of introduction and establishment of an alien pathogen and to prediction of the spread and associated impact of an alien pathogen on native biota and ecosystems. The development of interdisciplinary capacity, expertise, and coordination to identify and manage threats was seen as critical to address knowledge gaps

Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity.

Global dispersal and increasing frequency of the SARS-CoV-2 spike protein variant D614G are suggestive of a selective advantage but may also be due to a random founder effect. We investigate the hypothesis for positive selection of spike D614G in the United Kingdom using more than 25,000 whole genome SARS-CoV-2 sequences. Despite the availability of a large dataset, well represented by both spike 614 variants, not all approaches showed a conclusive signal of positive selection. Population genetic analysis indicates that 614G increases in frequency relative to 614D in a manner consistent with a selective advantage. We do not find any indication that patients infected with the spike 614G variant have higher COVID-19 mortality or clinical severity, but 614G is associated with higher viral load and younger age of patients. Significant differences in growth and size of 614G phylogenetic clusters indicate a need for continued study of this variant