Comparison of 10 × 1-minute high-intensity interval training (HIIT) versus 4 × 4-minute HIIT on glucose control and variability in females with type 2 diabetes.

Two high-intensity interval training (HIIT) regimens are often used in research and clinical settings. Yet, there has been no direct comparison to determine if one can improve glucose control and variability to a greater extent in individuals living with type 2 diabetes (T2D). Fourteen older females with T2D participated in a semi-randomized control trial where HIIT10 (10 × 1-min intervals at 90% heart rate max; HRmax) and HIIT4 (4 × 4-min intervals at 90% of HRmax) were compared to a control condition (CON; no exercise). Continuous glucose monitoring was used to assess glucose control and variability over 24 h after each condition. Both HIIT10 (-2.1 ± 1.1 mmol/L) and HIIT4 (-2.1 ± 1.3 mmol/L) acutely lowered glucose compared to CON (-0.7 ± 0.8 mmol/L; p = 0.001), with no difference between exercise conditions. This glucose-lowering effect did not persist over the 24-h post-exercise period, as both mean glucose (p = 0.751) and glucose variability (p = 0.168) were not significantly different among conditions. However, exploratory analyses focusing on individuals with less optimal glucose control (above median 24-h mean glucose in the CON condition; n = 7) revealed that 24-h mean glucose (7.4 [7.14-8.92] vs. 8.4 [7.5-9.9] mmol/L; p = 0.048), glucose variability (p = 0.010), and peak glucose (p = 0.048) were lower following HIIT10 compared to CON, while HIIT4 reduced time spent in moderate hyperglycemia compared to CON (p = 0.023). Both HIIT10 and HIIT4 acutely lower glycemia, but the effect does not persist over 24 h. However, in individuals with worse glucose control, HIIT10 may improve mean 24-h glucose and glycemic variability, while HIIT4 may reduce time spent in moderate hyperglycemia.

Low-volume walking HIIT: Efficient strategy to improve physical capacity and reduce the risk of cardiovascular disease in older women with type 2 diabetes.

BACKGROUND AND AIMS: To compare the effect of a low-volume walking high-intensity interval training (HIIT) to moderate-intensity continuous training (MICT) on risk of cardiovascular diseases and physical capacity in older women with type 2 diabetes (T2D). METHODS: Thirty inactive older women with T2D were randomized into either HIIT (75 min/week) or MICT (150 min/week). Cardiovascular risk profile (lipid profile; waist circumference and fat mass; resting, post-exercise and ambulatory blood pressure [BP]; VO2 peak; UKPDS score; ABC's) and physical capacity were assessed before and after a 12-week intervention. RESULTS: While resting systolic and diastolic BP (all p ≤ 0.01) were reduced, ambulatory BP (p ≥ 0.49) and lipid profile (p ≥ 0.40) remained unchanged after the intervention. Although VO2 peak increased to a similar extent in both groups (p = 0.015), the distance covered during the 6MWT (p = 0.01) and grip strength (p = 0.02) increased to a greater extend in HIIT. The UKPDS risk score decreased in both groups after the intervention (p = 0.03) and 31% of the participants reached the ABC's compared to 24% at baseline. CONCLUSION: Low-volume walking HIIT is an efficient exercise intervention for older women with T2D as it improved some CVD risk factors and physical capacity. Nevertheless, neither low-volume HIIT nor MICT is sufficient to affect ambulatory blood pressure in T2D patients.

Feasibility and impacts of supervised exercise training in subjects with obesity awaiting bariatric surgery: a pilot study.

BACKGROUND: To optimize bariatric surgery results, experts recommend regular practice of physical activity. However, no precise recommendations are available for the pre-surgical period. We aimed to evaluate, in this pilot study, the feasibility of a supervised Pre-Surgical Exercise Training (PreSET) and its short-term clinical impacts in subjects awaiting bariatric surgery. METHODS: In addition to the usual interdisciplinary lifestyle management, eight women and four men [40.8 (37.6-47.5) years old, BMI = 51.4 (43.8-53.1) kg/m(2)] underwent the PreSET, which combined both endurance and strength training. They were instructed to perform three physical activity sessions per week during 12 weeks, with at least two sessions per week on site and the possibility to complete missed sessions at home. Before and after the PreSET, anthropometric measures, body composition, physical fitness, quality of life, and physical exercise beliefs were assessed. RESULTS: The subjects participated in 57.3 % of the total supervised exercise sessions proposed and presented high satisfaction rates. Our program resulted in a significant improvement in weight (p = 0.007), physical fitness (p ≤ 0.05), and quality of life score (p = 0.012) as well as for the emotions, social interactions, and sexual life subscales (p < 0.03). Fear of injury (p = 0.028) and embarrassment during physical activity (p = 0.028) were significantly decreased, whereas no significant change in confidence in athletic ability and in beliefs in exercise benefits were noticed after the program. CONCLUSIONS: PreSET is feasible in subjects awaiting bariatric surgery and, combined with an interdisciplinary management, results in several short-term benefits.