| Outcome Measures: |
Primary: Change in postprandial glycemic control as assessed by mean blood glucose concentration during a 4 hour mixed-meal tolerance test, Day 0 (before randomisation), 17 (after initiation of metformin/placebo treatment), 101 (after 12 weeks of training) | Secondary: Change in free-living glycemic control, Blood HbA1c levels, Day 0 (before randomisation), 17 (after initiation of metformin/placebo treatment), 101 (after 12 weeks of training)|Change in endogenous glucose production as assessed by rate of infused glucose tracer appearance in blood, Day 0 (before randomisation), 17 (after initiation of metformin/placebo treatment), 101 (after 12 weeks of training)|Change in exogenous glucose uptake as assessed by rate of ingested glucose tracer appearance in blood, Day 0 (before randomisation), 17 (after initiation of metformin/placebo treatment), 101 (after 12 weeks of training)|Change in peripheral glucose uptake as assessed by rate of glucose disappearance from blood, Day 0 (before randomisation), 17 (after initiation of metformin/placebo treatment), 101 (after 12 weeks of training)|Change in maximal oxygen consumption, Maximal oxygen uptake during an incremental bicycle test, Day 17 (after initiation of metformin/placebo treatment), 101 (after 12 weeks of training)|Change in body weight, Body weight measured by standard procedures, Day 17 (after initiation of metformin/placebo treatment), 101 (after 12 weeks of training)|Change in lean body mass, Lean body mass evaluated via Dual energy x-ray absorptiometry (Dxa), Day 17 (after initiation of metformin/placebo treatment), 101 (after 12 weeks of training)|Change in total fat mass, Total body fat mass evaluated via Dual energy x-ray absorptiometry (Dxa), Day 17 (after initiation of metformin/placebo treatment), 101 (after 12 weeks of training)|Change in visceral fat mass, Visceral fat mass evaluated via magnetic resonance imaging (MRI) scans, Day 17 (after initiation of metformin/placebo treatment), 101 (after 12 weeks of training)|Change in AMPK activity in skeletal muscle, AMPK activity measured via western blotting and activity assays, Day 17 (after initiation of metformin/placebo treatment), 101 (after 12 weeks of training)|Change in skeletal muscle oxidative stress, Muscle mitochondrial oxidative stress measured via respirometry in muscle biopsies, Day 17 (after initiation of metformin/placebo treatment), 101 (after 12 weeks of training)|Change in systemic oxidative stress, Systemic oxidative stress measured via RNA/DNA oxidation products in urine, Day 0 (before randomisation), 17 (after initiation of metformin/placebo treatment), 101 (after 12 weeks of training)|Maximal mitochondrial respiration, Maximal mitochondrial respiration measured via respirometry in muscle biopsies, Day 17 (after initiation of metformin/placebo treatment), 101 (after 12 weeks of training)|Training heart rate, Heart rate will be measured continuously during all training sessions, Average heart rate during all training sessions (through study completion, [Day 101])|Training rate of perceived exertion, Rate of perceived exertion measured via a Borg scale (range 6-20 where higher values indicate higher rate of perceived exertion) will be assessed for each training session, Average rate of perceived exertion of all training sessions (through study completion, [Day 101])
|
