2 RESEARCH ARTICLES
Karstoft K1, Winding K, Knudsen SH, James NG, Scheel MM, Olesen J, Holst JJ, Pedersen BK, Solomon TP.
– Elucidate the underlying mechanisms behind the advantageous effects of interval walking training (IWT) compared with continuous walking training (CWT) on glycaemic control in individuals with type 2 diabetes.
(1) The improved glycaemic control, which was only seen in the IWT group, was consistent with IWT-induced increases in insulin sensitivity index with no changes in the CWT or CON group.
(2) Moreover, only IWT improved insulin signalling in skeletal muscle.
– These results suggest that training with alternating intensity, and not just training volume and mean intensity, is a key determinant of changes in whole body glucose disposal in individuals with type 2 diabetes.
Kristian Karstoft, Kamilla Winding, Sine H. Knudsen, Jens S. Nielsen, Carsten Thomsen, Bente K. Pedersen, Thomas P.J. Solomon
– Evaluate the feasibility of free-living walking training in type 2 diabetic patients
– Investigate effects of interval-walking training vs. continuous-walking training upon physical fitness, body composition, glycemic control
– Subjects with type 2 diabetes were randomized to:
(1) Control (n = 8)
(2) Continuous-walking (n = 12): performed all training at moderate intensity
(3) Interval-walking group (n = 12): alternated 3-min repetitions at low and high intensity
– Training groups were prescribed 5 sessions per wk (60 min/session) and were controlled with an accelerometer and heart-rate monitor
– Before and after the 4-month intervention, the following variables were measured: VO2max, body composition, and glycemic control (fasting glucose, HbA1c, oral glucose tolerance test, and continuous glucose monitoring [CGM])
(1) Training adherence was high (89 ± 4%), and training energy expenditure and mean intensity were comparable
(2) VO2max increased 16.1 ± 3.7% in the interval-walking group, whereas no changes were observed in the continuous-walking or control group
(3) Body mass and adiposity (fat mass and visceral fat) decreased in the interval-walking group only
(4) Glycemic control (elevated mean CGM glucose levels and increased fasting insulin) worsened in the control group
(5) Whereas mean and maximum CGM glucose levels decreased in the interval-walking group
(6) The continuous walkers showed no changes in glycemic control
– Free-living walking training is feasible in type 2 diabetic patients
– Continuous walking offsets the deterioration in glycemia seen in the control group, and interval walking is superior to energy expenditure–matched continuous walking for improving physical fitness, body composition, and glycemic control