Current Projects in Centre for Exercise Medicine, Physical Activity and Health

According to the World Health Organisation, 422 million people are living with diabetes, and in Northern Ireland, over 100,000 people are diagnosed with diabetes. The NHS spent over £9.8 billion on diabetes in 2016, of which 80% was associated with long-term complications that could have been avoided.

It is estimated that by 2035, 17% of the NHS budget will be spent on treating diabetes-related complications but a saving of £340 million is possible if glycaemic control is improved. Hyperglycaemia persists in diabetes despite exogenous insulin therapy, leading to potentially life-threatening complications including diabetic ketoacidosis, retinopathy, nephropathy and neuropath.  Individuals with diabetes are reliant on exogenous insulin therapy and dietary modifications to establish a state of euglycemia.

The pathogenesis of T1DM is predominantly genetic, while gene modifications through environmental stimuli may play a role in the development of this autoimmune condition. DNA methylation occurs without changing the nucleotide base pairing sequence and can subsequently repress gene expression. Although exercise improves blood glucose control by activating GLUT-4 protein, little is known regarding DNA methylation following exercise in T1DM. The aim of our work in this emerging area is to examine DNA methylation and glucose control following exercise in diabetes mellitus.

Contacts:  Prof Gareth Davison; Prof Colum Walsh

During a given year, one in four individuals report experiencing poor mental health, 300 million of which experience depression. Exercise positively contributes to mental health outcomes, with meta-analytic evidence indicating that both aerobic and resistance exercise can reduce symptoms of depression. In the United Kingdom Public Health Policy, Exercise Referral Schemes (ERSs) are intended to support clinicians with the management and treatment of mental ill-health within society. Yet, the evidence underpinning their effectiveness for mental health issues has been sparse, and predominantly limited to physical health conditions.

The relationship between physical activity and mental health is complex and encompasses a range of underlying neurobiological, psychological and social mechanisms that have yet been tested in great detail. One psychosocial mechanism derived from Self-Determination Theory, that can support in the design, delivery and assessment of interventions such as ERSs is the degree to which individuals’ psychological needs for autonomy, competence and social relatedness are supported and satisfied during their physical activity participation. Intervention deliverers (e.g. instructors, personal trainers) can be trained to offer participants physical activity choices (i.e. autonomy support), positive instructional feedback during tasks (i.e. competence support), and a helpful supportive relationship (i.e. relatedness support). Collectively, such provision may increase programme engagement, and allow for the testing of indirect mediating mechanisms underlying the relationship between physical activity and mental health.

This inter-disciplinary PhD study will advance on-going mental health intervention programmes among those with poor mental health. The study will examine if needs-supportive techniques (from instructors) can exert an influence on a causal pathway (i.e. needs-support > needs satisfaction > motivational regulation) between physical activity and mental health outcomes (e.g. self-reported health, biomarkers of stress).

Objectives of the research

1. To consider the efficacy of current practice on the use of ERS’s for enhancing mental health.
2. In consultation with individuals and leisure support services develop a theoretically- informed intervention programme.
3. To extend current knowledge around the motivational mechanisms underpinning the relationship between physical activity and mental health using SDT.

Contacts:  Dr Gavin Breslin; Dr Stephen Shannon; Prof Mark Tully

Supervisory team: Dr Andrea McNeilly (SESRI), Dr Conor McClean (SESRI), Dr Sonyia McFadden (Institute of Nursing and Health Research)

Exercise is generally considered beneficial for bone health. However, research has consistently demonstrated that many endurance athletes suffer from poor bone mineral density. The cause of low bone mineral density in endurance athletes is largely unknown, although several mechanisms have been suggested. Recently, several investigations have considered the exercise-induced decrease of ionised calcium (Ca²⁺) and its ability to promote parathyroid hormone, as a potential mechanism responsible for increased bone breakdown. Although it has been repeatedly observed that Ca²⁺decreases with exercise, it remains unknown why this occurs and whether this is dependent on the intensity of bouts. The acid-base changes which occur during exercise may also influence this response but have yet to be fully elucidated.

One additional area of particular interest is the influence of reduced oxygen availability (hypoxia) on bone cells and calcium metabolism. It has been shown that reduced oxygen availability directly influences bone cell metabolism promoting bone breakdown per se. Combined with the potential of exercise to affect bone and calcium metabolism, this requires further scrutiny especially given the growing interest in hypoxic training techniques (i.e. altitude camps).

Scott’s Doctoral research aims to investigate the potential impact of exercise on drivers of bone turnover and calcium metabolism and how these respond, if at all, to: exercise of varying intensities; hypoxic conditions and; attempts to limit control the acid-base milieu (through supplementation).

Contacts:  Dr Andrea McNeilly; Dr Conor McClean; Dr Sonyia McFadden