Implementing an exercise intervention on young adults at university with type 1 diabetes.

Diabetes mellitus is a multifactorial disease, which manifests as an intolerance of metabolising glucose from the bloodstream, resulting in elevated levels of glucose (de Ferranti et al., 2014). Contrary to the gradual increase in insulin resistance and body fat which are standard components of type 2 diabetes, type 1 diabetes (T1DM) is recognised as by insulin deficiencies because of the autoimmune driven destruction of pancreatic β cells (Sigal et al., 2013).

Globally, T1DM affects over 1 million young people aged between the ages of 0 to 20 years and this number is on the rise (International Diabetes Federation 2019). As a whole, the T1DM population encounter many hurdles when dealing with their condition, from coping with insulin regimes, sleeping, dietary and exercise adjustments to diabetic ketoacidosis (DKA). Even though the scientific world has been making tremendous strides in combatting diabetes, the life expectancy of those has been drastically reduced by an average of 11-13 years (Livingstone et al., 2015). This is caused by being exposed to prolonged hyperglycaemic periods which contribute to the development of chronic diabetic complications such as irreversible tissue damage. In people with T1DM, macrovascular disease is the leading cause of death (Graves, Donaghue 2019).

The medical therapy for T1DM is based on insulin administration, adjusted diet and regular physical exercise. Regular physical activity is considered to be an essential component of managing T1DM. The physiological, social and emotional benefits of daily physical activity are well known, and they are of vital importance for people with T1DM. Regular physical activity contributes to improvement in overall health and fitness and reduces the risks of developing some diabetic complications such as retinopathy (Jendle, Riddell 2019, Riddell, Gallen et al. 2017a, Kriska, LaPorte et al. 1991a). Yet, for many people with T1DM, regular exercise is almost a "taboo" topic as many people may feel, performing such physical activity would exacerbate their already unbalance inner ecosystem.

The overarching goal of this thesis was to determine the overall impact of performing a combination of cardiovascular and resistance exercise at a submaximal intensity level of 50-60%, on subjects with T1DM. The study's aim was to educate and encourage subjects with T1DM to take a proactive stance with their health and lifestyle choices.

Program Outline Students from the university were recruited through various open days, fairs and smoothie nights hosted at De Montfort University Leicester. This study aimed to attract students with and without T1DM. A total of 45 participants were recruited into this study, of those participants 32 had T1DM and 13 were considered healthy. This intervention study spanned across a period of 8-weeks, in which participants would be required to train twice-weekly for the 6-week duration. Each exercise session would last 2-hours. Every exercise-session would consist of a warm-up, five core resistance exercises combined with 20-minutes of cycling at a maintained target heart rate, followed by a cool-down. All the exercises performed by the candidates would be completed to a 50-60% of their maximum intensity levels determined using the one-repetition max Bryzycki equation and Karvonen's formula. The combination study would include multiple baseline recording sessions for an array of measurements such as for measures of strength and anthropometric measurements. The participants would also be required to perform glucose challenges on three separate occasions (before beginning exercise, after the first bout of exercise and finally after the twelfth bout of exercise), where four-interval samples of blood would be drawn. From each subject, a total of twenty-one blood samples were taken per over the course of the intervention.

Objectives of each investigation The objective of this thesis was to develop a greater understanding of how performing a regimented exercise program would influence the biological responses of young adults with T1DM. This study is divided into four main experiments;

initially, this study investigated how subjects with and without T1DM, regulated the metabolism of 75-gram doses of glucose alongside monitoring the insulin sensitivity across various time-points throughout the exercise intervention; secondly, this study then observed the influence of the exercise intervention on the inflammatory biomarker response of both cohorts; thirdly, this study examined the biometric evolutions throughout the intervention; finally, this study employed the use of a questionnaire which analysed the psychological well-being of both cohorts on their journey throughout the intervention. The outcome of the investigations The main results from the investigations revealed that both the T1DM and healthy cohorts demonstrated a significant increase in the estimated glucose disposal rate after completing the exercise intervention (8.60 ± 1.34 vs 9.12 ±1.32 mg/kg/min (p<0.005)), (11.31 ± 0.54 vs 11.567 ± 0.44 mg/kg/min (p<0.01)), respectively.

After completing the exercise intervention both the T1DM and healthy cohorts demonstrated a significant reduction in their HbA1c levels with a before-intervention x̅ = 75 mmol/mol, �� = 15.8 vs. after-intervention x̅ = 69 mmol/mol, �� = 13.4, (P < 0.001) and before-intervention x̅ = 36 mmol/mol, �� = 2.7 vs. after-intervention x̅ = 32 mmol/mol, �� = 1.8, (P < 0.001), respectively.

The changes seen in both the healthy and T1DM cohorts across the exercise intervention are the same. The impact on both cohorts performing 12 exercise sessions is equivalent with respect to the biochemical and psychological trends generated on completion. This study was able to demonstrate the beneficial impact of undertaking a controlled program of combined resistance and cardiovascular exercise without any reported incidences of late hypoglycaemia. Overall, this investigation's findings highlight some key issues that influence the overall physical and psychological wellbeing of people with T1DM at university.