The acute effects of interval- vs. continuous-walking exercise on glycemic control in subjects with type 2 diabetes: a cross-over, controlled study

TY - JOUR

T1 - The acute effects of interval- vs. continuous-walking exercise on glycemic control in subjects with type 2 diabetes

T2 - a cross-over, controlled study

AU - Karstoft, Kristian

AU - Christensen, Camilla S

AU - Pedersen, Bente K

AU - Solomon, Thomas

PY - 2014/9/1

Y1 - 2014/9/1

N2 - Context: Glycemic control improves with physical activity, but the optimal exercise mode is unknown.Objective: The objective of the study was to determine whether interval-based exercise improves postprandial glucose tolerance and free-living glycemia more than oxygen consumption- and time duration-matched continuous exercise.Design: This was a crossover, controlled study with trials performed in randomized order.Setting: The study was conducted in hospitalized and ambulatory care.Patients: Patients diagnosed with type 2 diabetes mellitus (n=10, no withdrawals) participated in the study.Interventions: Subjects performed three 1-hour interventions: 1) interval walking (IW; repeated cycles of 3 min of slow and fast walking); 2) continuous walking (CW); and 3) control (CON). Oxygen consumption (VO2) was measured continuously to match mean VO2between exercise sessions (∼75% VO2peak).Main Outcome Measures: A mixed-meal tolerance test (MMTT; 450 kcal, 55% carbohydrate) with stable glucose isotopic tracers was provided after each intervention, and glucose kinetics were measured during the following 4 hours. Free-living glycemic control was assessed for approximately 32 hours after the MMTT using continuous glucose monitoring.Results: VO2was well matched between the exercise interventions. IW decreased the mean and maximal incremental plasma glucose during theMMTTwhen compared with the CON (mean 1.2± 0.4 vs 2.0 ± 0.5 mmol/L, P < .001; maximal 3.7 ± 0.6 vs 4.6 ± 0.7 mmol/L, P = .005) and mean when compared withCW(1.7±0.4 mmol/L, P=.02). No differences in the mean or maximal incremental plasma glucose values were seen between the CW and CON. The metabolic clearance rate of glucose during theMMTTwas increased in theIWcompared withCW(P=.049) andCON(P<.001). Continuous glucose monitoring mean glucose was reduced in IW compared with CW for the rest of the intervention day (8.2±0.4 vs 9.3±0.7 mmol/L, P=.03), whereas no differences were found between IW and CW the following day.Conclusions: One interval-based exercise session improves glycemic control in type 2 diabetes mellitus subjects when compared with an oxygen consumption- and time duration-matched continuous exercise session.

AB - Context: Glycemic control improves with physical activity, but the optimal exercise mode is unknown.Objective: The objective of the study was to determine whether interval-based exercise improves postprandial glucose tolerance and free-living glycemia more than oxygen consumption- and time duration-matched continuous exercise.Design: This was a crossover, controlled study with trials performed in randomized order.Setting: The study was conducted in hospitalized and ambulatory care.Patients: Patients diagnosed with type 2 diabetes mellitus (n=10, no withdrawals) participated in the study.Interventions: Subjects performed three 1-hour interventions: 1) interval walking (IW; repeated cycles of 3 min of slow and fast walking); 2) continuous walking (CW); and 3) control (CON). Oxygen consumption (VO2) was measured continuously to match mean VO2between exercise sessions (∼75% VO2peak).Main Outcome Measures: A mixed-meal tolerance test (MMTT; 450 kcal, 55% carbohydrate) with stable glucose isotopic tracers was provided after each intervention, and glucose kinetics were measured during the following 4 hours. Free-living glycemic control was assessed for approximately 32 hours after the MMTT using continuous glucose monitoring.Results: VO2was well matched between the exercise interventions. IW decreased the mean and maximal incremental plasma glucose during theMMTTwhen compared with the CON (mean 1.2± 0.4 vs 2.0 ± 0.5 mmol/L, P < .001; maximal 3.7 ± 0.6 vs 4.6 ± 0.7 mmol/L, P = .005) and mean when compared withCW(1.7±0.4 mmol/L, P=.02). No differences in the mean or maximal incremental plasma glucose values were seen between the CW and CON. The metabolic clearance rate of glucose during theMMTTwas increased in theIWcompared withCW(P=.049) andCON(P<.001). Continuous glucose monitoring mean glucose was reduced in IW compared with CW for the rest of the intervention day (8.2±0.4 vs 9.3±0.7 mmol/L, P=.03), whereas no differences were found between IW and CW the following day.Conclusions: One interval-based exercise session improves glycemic control in type 2 diabetes mellitus subjects when compared with an oxygen consumption- and time duration-matched continuous exercise session.

U2 - 10.1210/jc.2014-1837

DO - 10.1210/jc.2014-1837

M3 - Journal article

C2 - 24905068

SN - 0021-972X

VL - 99

SP - 3334

EP - 3342

JO - Journal of Clinical Endocrinology and Metabolism

JF - Journal of Clinical Endocrinology and Metabolism

IS - 9

M1 - jc20141837

ER -