None listed
Conditions
Brief summary
The aim of our study is to investigate the effects of a novel intervention - high-intensity aerobic interval training - on aerobic fitness, heart volumes and function, metabolic control, substrate utilization, nerve function and cardiovascular risk factors among women with previous gestational diabetes mellitus (pGDM). Women with pGDM have an exceptionally high (at least a 7-fold higher risk) risk of developing type 2 diabetes mellitus compared with women without pGDM. Previous GDM is associated with subclinical atherosclerosis prior to the development of the metabolic syndrome or T2D. There may also be subclinical heart dysfunction, however this has rarely been examined and responses to exercise training have not been investigated. It has been demonstrated recently that peripheral nerve dysfunction precedes the development of neuropathy in T2D and given that pGDM is associated with subclinical atherosclerosis prior to the development of the metabolic syndrome or T2D, nerve dysfunction may also be evident among women with pGDM, however, this has not been examined. There is an inverse relationship between physical activity and risk of type 2 diabetes mellitus (T2D) among women with pGDM. In fact, achieving the minimum recommended exercise targets (150 min of moderate-intensity exercise per week) halved the risk of developing T2D among women with pGDM. No studies have examined effects of high-intensity exercise training among women with pGDM.
Interventions
After baseline tests are performed, subjects will be randomised to either the exercise training group or the usual care (exercise advice) group. Exercise training: Subjects randomly allocated to the exercise training group will undertake supervised high-intensity exercise training three times per week for eight weeks. Training will be conducted on a stationary exercise bike, located at either RPA Hospital or a gym close to the subject's home – whichever is more convenient for them. The training physiotherapist or exercise physiologist will supervise each training session and will monitor heart rate and symptom scores. As all sessions are supervised, attendance will be recorded throughout the training period. Participants will wear a heart rate monitor, i.e. sensing strap on their chest, and a watch. In the first week of training, after a 5-min warm-up, cycling at a low load, subjects will do six 30-s efforts on the bike at a heart rate that is about 80-90% of their maximum heart rate. For two minutes between each effort subjects will pedal at an easy load at 60-70% of maximum heart rate. At the end of the session they will pedal at a low load for a 5-minute cool down. The physiotherapist/exercise physiologist will increase the exercise periods to 60 s in the second week of training; and to two minutes for the final 6 weeks of exercise training. Recovery periods between exercise bouts will remain at two minutes. Each exercise training session will therefore only take between 25 to 35 minutes.
Sponsors
Dr Alison Harmer
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Blinded (masking used) (Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
18 Years to 45 Years
Healthy volunteers
No
Inclusion criteria
Glucose intolerance first diagnosed during pregnancy; at least 6 months post-partum; not currently breast-feeding; aged between 18 and 45 years of age. Current glucose intolerance not required.
Exclusion criteria
Chronic respiratory disease; current history of smoking; chest wall disease; heart failure; stroke; overt cardiovascular disease; and any other condition in which exercise is contraindicated; any condition precluding the ability to provide informed consent; pregnancy; and residence > 50 km from the hospital.
Outcome results
None listed