A protocol study to investigate the acute vascular and metabolic effects of nicotinamide riboside and pterostilbene co-supplementation

Effective mitochondrial and vascular function are key to maintaining general health and optimising endurance exercise performance. This thesis aims to discuss some key players regulating these functionalities, and a promising strategy to upregulate these pathways. Specifically, the supplementation of nicotinamide riboside (NR), an NAD+ precursor, and pterostilbene (PT), a polyphenol (together referred to as NRPT). Clinical data regarding the independent and combined metabolic and vascular actions of NR, PT, and NRPT supplementation are reviewed in detail. The possible beneficial effects of co-supplementation on glycaemic control will also be discussed, as well as the role of post-exercise hypoxic exposure on post-exercise glucose uptake. The review discusses the use of two stimuli, acute hyperglycaemia and acute hypoxic exposure, which could potentiate the vascular effects of NRPT. Within this, an in-depth summation of literature regarding the impact of a standardised glucose load on flow-mediated dilation in healthy populations is provided. Currently, only four clinical trials have investigated NRPT supplementation (chronic and short-term), either in vulnerable or elderly populations with a limited range of metabolic and vascular outcome measures. Consequently, no data exists regarding acute dosages, supplementation in younger cohorts, or its impact during exercise. The original aim of this thesis was to address this gap in the literature; however, due to COVID-19 the research could not take place. Therefore, this thesis contains the rationale for this study and the proposed methodology that planned to utilise a randomised, double-blind, and placebo-controlled design. Briefly, the impact of acute NRPT supplementation on vascular function, substrate utilisation during exercise, and post-exercise glycaemic control were going to be assessed, with the primary outcome measure being brachial artery flow-mediated dilation (FMD). The relatively underexplored area of post-exercise hypoxic exposure on post-exercise glucose uptake was also included in the investigation. Lastly, this thesis also contains results of an FMD repeatability study conducted prior to COVID-19. Completion of this was required before the start of experimental testing to demonstrate a certain degree of sonography competence to ensure FMD measurements would be reliable. Each participant (n=8) attended three lab visits, where FMD was measured twice, 1 hr apart, totalling six measurements. Analysis showed an inter- and intra-day coefficient of variation of 13.7% and 9.0%, respectively

The intensity paradox:A systematic review and meta‐analysis of its impact on the cardiorespiratory fitness of older adults

Aim: The present systematic review and meta‐analysis aimed to compare the effect of moderate‐ versus high‐intensity aerobic exercise on cardiorespiratory fitness (CRF) in older adults, taking into account the volume of exercise completed. Methods: The databases MEDLINE (Ovid), EMBASE (Ovid), and CENTRAL (Cochrane Library) were searched to identify randomized controlled trials (RCTs). Two reviewers extracted data and assessed bias. Comprehensive Meta‐Analysis software calculated overall effect size, intensity differences, and performed meta‐regression analyses using pre‐to‐post intervention or change scores of peak oxygen uptake (V̇O2peak). The review included 23 RCTs with 1332 older adults (intervention group: n = 932; control group: n = 400), divided into moderate‐intensity (435 older adults) and high‐intensity (476 older adults) groups. Results: Meta‐regression analysis showed a moderate, but not significant, relationship between exercise intensity and improvements in V̇O2peak after accounting for the completed exercise volume (β = 0.31, 95% CI = [−0.04; 0.67]). Additionally, studies comparing moderate‐ versus high‐intensity revealed a small, but not significant, effect in favor of high‐intensity (Hedges' g = 0.20, 95% CI = [−0.02; 0.41]). Finally, no significant differences in V̇O2peak improvements were found across exercise groups employing various methods, modalities, and intensity monitoring strategies. Conclusion: Findings challenge the notion that high‐intensity exercise is inherently superior and indicate that regular aerobic exercise, irrespective of the specific approach and intensity, provides the primary benefits to CRF in older adults. Future RCTs should prioritize valid and reliable methodologies for monitoring and reporting exercise volume and adherence among older adults

Identification of a resistance gene Rpi-dlc1 to Phytophthora infestans in European accessions of Solanum dulcamara

Initial screening of 14 Solanum dulcamara accessions enabled the identification of individuals resistant and susceptible to Phytophthora infestans. Crosses between contrasting genotypes resulted in three F2–BC1 populations segregating for resistance to late blight in a laboratory assay and under field conditions. Genetic profiling of one of these populations using 128 AFLP primers generated three markers linked to the resistant phenotype. Blast analysis of the sequenced markers resulted in a plausible gene position on the distal end of the long arm of chromosome 9 that could be confirmed by CAPS markers. Thus, we describe a first resistant gene, named Rpi-dlc1, from S. dulcamara, a Solanum species native to Europe. In addition, one population was tested for broadness of resistance responses using a set of seven additional P. infestans isolates, varying in virulence. This indicated the possible presence of additional Rpi genes

HIIT at Home: Enhancing Cardiorespiratory Fitness in Older Adults – A Randomised Controlled Trial

Background: This study aimed to investigate the effectiveness of a six-month home-based high-intensity interval training (HIIT) intervention to improve peak oxygen consumption (V̇O2peak) and lactate threshold (LT) in older adults. Methods: 233 healthy older adults (60-84 years; 54% females) were randomly assigned to either six-month, thrice-weekly home-based HIIT (once-weekly circuit training and twice-weekly interval training) or a passive control group. Exercise sessions were monitored using a Polar watch and a logbook for objective and subjective data, respectively, and guided by a personal coach. The outcomes were assessed using a modified Balke protocol combining V̇O2peak and LT measures.1 General linear regression models assessed between-group differences in change and within-group changes for each outcome. Results: There was a significant between-group difference in the pre-to-post change in V̇O2peak (difference: 1.8 [1.2;2.3] mL/kg/min; exercise: +1.4 [1.0;1.7] mL/kg/min; control: -0.4 [-0.8;-0.0] mL/kg/min; effect size (ES):0.35). Compared to controls, the exercise group had lower blood lactate concentration (-0.7 [-0.9;-0.4] mmol/L, ES:0.61), % of peak heart rate (-4.4 [-5.7;-3.0], ES:0.64), and % of V̇O2peak (-4.5 [-6.1;-2.9], ES:0.60) at the intensity corresponding to pre-intervention LT, and achieved a higher treadmill stage at LT (0.6 [0.3;0.8]; ES:0.47), following the intervention. Conclusion: This study highlights the effectiveness of a home-based HIIT intervention as an accessible and equipment-minimal strategy to induce clinically meaningful improvements in cardiorespiratory fitness in older adults. Over six months, the exercise group showed larger improvements in all outcomes compared to the control group. Notably, the LT outcome exhibited a more pronounced magnitude of change than V̇O2peak

Cerebral blood flow and arterial transit time responses to home-based exercise training in healthy older adults

Brain vascular health worsens with age, evident by grey matter cerebral blood flow (CBFGM) reductions and lengthening arterial transit time (ATTGM). Exercise training can improve aspects of brain health in older adults, yet its effects on CBFGM and ATTGM remain unclear. This randomised controlled trial assessed responses of CBFGM and ATTGM to a 26-week home-based exercise intervention in 65 healthy older adults (control; n=33, exercise; n=32, aged 60–81 years), including whether changes in CBFGM or ATTGM were associated with cognitive function changes. Multi-delay pseudo-continuous arterial spin labelling data were used to estimate resting global and regional CBFGM and ATTGM. Results showed no between-group differences in CBFGM or ATTGM following the intervention. However, exercise participants with the greatest cardiorespiratory gains (n=17; ∆V̇O2peak>2 mL/kg/min) experienced global CBFGM reductions (-4.0 [-7.3, -0.8] mL/100 g/min). Furthermore, within the whole exercise group, cardiorespiratory fitness gains were associated with global CBFGM declines (β=-0.43 [-0.81, -0.04]), but no association was present with ATTGM. No changes in cognitive function or associations with CBFGM/ATTGM changes were observed. Our findings indicate exercise training in older adults may induce global CBFGM reductions, which are associated with the magnitude of cardiorespiratory fitness gains, but do not appear to affect cognitive function

Fitness, Ageing, and Bilingualism

Investigating the benefits of regular physical activity and bilingualism for the amelioration of cognitive decline in old age

The effect of temperature on carbon steel corrosion under geological conditions

International audienc