High-intensity aerobic interval training improves aerobic fitness and HbA1c among persons diagnosed with type 2 diabetes.
OBJECTIVE
It remains to be established how high-intensity aerobic interval training (HAIT) affects risk factors associated with type 2 diabetes (TD2). This study investigated effects of HAIT on maximal oxygen uptake (VO2max), glycated Hemoglobin type A1C (HbA1c), insulin resistance (IR), fat oxidation (FatOx), body weight (BW), percent body fat (%BF), lactate threshold (LT), blood pressure (BP), and blood lipid profile (BLP) among persons with T2D. Results were compared to the effects after a moderate-intensity training (MIT) program.


METHODS
Thirty-eight individuals with T2D completed 12 weeks of supervised training. HAIT consisted of 4 × 4 min of walking or running uphill at 85-95% of maximal heart rate, and MIT consisted of continuous walking at 70-75% of maximal heart rate.


RESULTS
A 21% increase in VO2max(from 25.6 to 30.9 ml kg-1min-1, p < 0.001), and a reduction in HbA1c by -0.58% points (from 7.78 to 7.20%, p < 0.001) was found in HAIT. BW and body mass index (BMI) was reduced by 1.9% (p < 0.01). There was a tendency towards an improved FatOx at 60% VO2max(14%, p = 0.065). These improvements were significant different from MIT. Both HAIT and MIT increased velocity at LT, and reduced %BF, waist circumference, hip circumference, and BP, with no significant differences between the two groups. Correlations were found between change in VO2maxand change in HbA1c when the two intervention groups were combined (R = -0.52, p < 0.01).


CONCLUSIONS
HAIT is an effective exercise strategy to improve aerobic fitness and reduce risk factors associated with T2D.
Department of Sports, Physical Education and Outdoor Life Studies, University College of Southeast Norway, Bø, Porsgrunn, Norway. Eva.m.stoa@hit.no.
Eva Maria
EM
Støa
Department of Endocrinology, Stavanger University Hospital, Former Hospital of Telemark, Stavanger, Norway.
Sondre
S
Meling
Department of Sports, Physical Education and Outdoor Life Studies, University College of Southeast Norway, Bø, Porsgrunn, Norway.
Lill-Katrin
LK
Nyhus
Department of Sports, Physical Education and Outdoor Life Studies, University College of Southeast Norway, Bø, Porsgrunn, Norway.
Glenn Strømstad
Department of Sports, Physical Education and Outdoor Life Studies, University College of Southeast Norway, Bø, Porsgrunn, Norway.
Karl Magnus
KM
Mangerud
Department of Sports, Physical Education and Outdoor Life Studies, University College of Southeast Norway, Bø, Porsgrunn, Norway.|Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.|Hokksund Medical Rehabilitation Center, Hokksund, Norway.
Jan
J
Helgerud
Department of Sports, Physical Education and Outdoor Life Studies, University College of Southeast Norway, Bø, Porsgrunn, Norway.
Solfrid
S
Bratland-Sanda
Department of Sports, Physical Education and Outdoor Life Studies, University College of Southeast Norway, Bø, Porsgrunn, Norway.
Øyvind
Ø
Støren
D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000378:metabolism / Q000628:therapy*; D005081:Exercise Therapy; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D000072696:High-Intensity Interval Training; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D010809:Physical Fitness
D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
Exercise intensity; Fat oxidation; HbA1c; Interval training; Maximal oxygen uptake