Strength Training vs. Aerobic for Diabetes.

Introduction: Individuals diagnosed with Type 2 Diabetes while maintaining a healthy weight (Body Mass Index, BMI < 25 kg/m2), or 'normal-weight type 2 diabetics', are found to be associated with sarcopenia - a condition characterized by the loss of muscle mass. Owing to this unique body composition, discerning the ideal exercise regime for such a population remains a complex task.

Objective: The primary objective of this study was to identify the most effective exercise regimen for normal-weight type 2 diabetics, comparing strength training, aerobic training, and a combination of both. The primary measure of effectiveness was the absolute change in HbA1c levels over the course of 3, 6, and 9 months. Furthermore, alterations in body composition were tracked as secondary outcomes.

Methodology: A randomized controlled trial (RCT) was carried out involving individuals diagnosed with Type 2 Diabetes (aged between 18-80 years, with HbA1c between 47.5-118.56 mmol/mol [6.5-13.0%]) and a BMI < 25 kg/m2. Recruitment was done either from outpatient clinics or through advertisements. Participants were randomly divided into three groups - strength training (ST), aerobic training (AER), and combined (COMB) - using stratified block randomization, for a 9-month exercise program. The exercises were carried out at community-based fitness centers. Notably, participants who completed at least half the sessions were included in the per-protocol analysis.

Results: A total of 186 participants, consisting of 63 in ST, 58 in AER, and 65 in the COMB group, were analyzed. The average participant was 59 years old, with a significant Asian representation (83%). The mean HbA1c level at the outset was 59.6 mmol/mol (7.6% [1.2%]). Results from the intention-to-treat analysis showed a substantial decrease in HbA1c levels in the ST group, unlike the COMB and AER groups. The ST group also outperformed the AER group in terms of improved HbA1c levels. An increase in lean mass relative to fat mass was exclusively observed in the ST group, which was found to independently predict HbA1c level changes. Only one adverse event was noted, which occurred in the COMB group, potentially linked to the exercise intervention.

Conclusion: The study concludes that strength training emerged as the superior choice compared to aerobic training alone, for HbA1c reduction in normal-weight Type 2 diabetics. No significant difference was found between strength training and combination training. Importantly, an increase in lean mass in relation to a decrease in fat mass was independently associated with a reduction in HbA1c levels. These findings could guide the formulation of personalized exercise plans for normal-weight Type 2 diabetics, with an emphasis on strength training exercises. Further studies are needed to explore the long-term effects and implications of different training regimens on this population.

Kobayashi, Y., Long, J., Dan, S. et al. Strength training is more effective than aerobic exercise for improving glycemic control and body composition in people with normal-weight type 2 diabetes: a randomized controlled trial. Diabetologia (2023). https://doi.org/10.1007/s00125-023-05958-9

While we think both strength training and aerobic exercise help to improve longstanding longevity, if time constraints prevent a plan for both, then it appears that strength training will lead to improved diabetes management. Jason & Rita...aka Dr. De Leon and Dr. Gillespie.