Blood Glucose Down, Insulin Sensitivity Up with 10 Minutes of Moderate-intensity Stair Stepping

Glucose and insulin levels decreased after just 3 minutes of the moderate-intensity exercise, a promising finding for those with type 2 diabetes, say authors of a new study.

Moderate intensity stair stepping lowered peak postprandial glucose and insulin concentrations in as few as 3 minutes and increased insulin sensitivity in 10 minutes after a standard glucose challenge, new research has found. The implications for stemming the progression of type 2 diabetes are promising, authors say.

Writing in Nutrition, Metabolism and Cardiovascular Diseases, investigators led by Jeff Moore, MS, professor at San Diego State University School of Exercise and Nutritional Science and a PhD student at the Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, observe that while exercise is known to attenuate the metabolic stresses of the postprandial response, “adherence is low with nearly 80% of Americans failing to meet the physical activity recommendations established by the CDC.”

They advocate accounting for common barriers to regular exercise which include time, perceived effort, intensity, and convenience. Stair stepping has been shown previously to reduce mealtime glucose response, they write, and also to be considered low-intensity exercise.

They set out in this study to examine the differential effect of various short duration, moderate intensity intervals on glycemic control.

The investigators recruited 30 healthy adults (60% men; mean age, 26.2 years) from October 2016 to August 2017 to participate in a crossover trial at an exercise physiology laboratory at San Diego State University. Eligibility criteria included a fasting blood glucose level between 80–125 mg/dL and a designation of low risk for exercise participation. All participants were nonsmokers.

OGTT and stair-stepping

Assessments were conducted at the required 5 visits to the laboratory as follows: Peak aerobic capacity was determined at the first visit followed at the second visit by a baseline resting oral glucose tolerance test (OGTT). At each of the next 3 visits an OGTT was combined with 1, 3, or 10 minutes of self-selected intensity stair climbing and descending. Participants chose a stepping pace between 90 and 110 steps per minute that they could maintain comfortably for 10 minutes, a pace that was held constant for them across visits.

Each visit began with consumption of a 75 g dextrose solution and was followed by stair climbing at 18 minutes for the 10-minute climb, at 25 minutes for the 3-minute climb, and at 27 minutes for the 1-minute climb. The intervals before the start of climbing allowed blood collection 30 minutes after the dextrose solution was consumed. Glucose, insulin, antioxidant capacity, and lactate during each of the 3 climbing interventions were compared with baseline values.

Post hoc analysis

Peak glucose was lower after 10 minutes of climbing (Δ –22.69; 95% CI, – 34.66 to –10.72; P<.002) and 3 minutes of climbing (Δ –15.37; 95% CI, – 25.05 to –5.69; P<.004) compared with baseline, but no change was observed with the 1-minute climbing intervention.

Insulin levels also decreased during 10 minutes of climbing (Δ –6.11; 95% CI, – 8.86 to –3.36; P<.001) and 3 minutes of climbing (Δ –2.59; 95% CI, – 4.54 to –0.63; P <.012) compared with baseline, but there was no difference with 1 minute of climbing.

Insulin sensitivity was significantly increased with the 10-minute climbing intervention (Δ 1.81; 95% CI, 0.03-3.58; P <.048) but no changes were seen with 3-minute or 1-minute intervention. There was no interaction observed between trial and time for antioxidant capacity or blood lactate level.

Moore et al note that this is one of the few studies to examine the impact of short stair stepping trials on postprandial insulin through insulin indices. And while it is well known that exercise can significantly reduce PPG and insulin in a time dependent manner, their findings indicate that even exercise of very short duration, requiring no equipment, and at a self-selected pace can be beneficial.

The unique aspects of stair stepping, they write, “may help overcome the poor compliance seen with other exercise interventions.”

They do note several limitations to the study, including limited timepoints, the use of dextrose rather than a mixed meal, and the study population consisting of only healthy younger adults.

“Future studies should investigate populations who have impaired glucose tolerance, insulin resistance, or overt diabetes who would be expected to see a greater benefit,” the researchers wrote.

Reference: Moore J, Bartholomae EM, Ward K, et al. Three minutes of moderate-intensity stair walking improves glucose and insulin but not insulin sensitivity or total antioxidant capacity. Nutr Metab Cardiovasc Dis. 2022;32:479-486.