Effects of a Single Exercise Bout on Insulin Sensitivity in Black and White Individuals

Abstract

These data suggest that insulin sensitivity is similar in blacks and age-, sex-, and body mass index-matched whites, but the glucose disposal pathways (storage vs. oxidation) are somewhat different. Compared with whites, blacks appear to have a greater capacity to increase glucose oxidation immediately after exercise and during insulin stimulation.

The Acute and Residual Effect of a Single Exercise Session on Meal Glucose Tolerance in Sedentary Young Adults

“…Likewise, insulin sensitivity was increased 12 hours after exercise compared to a no-exercise trial in young men who performed multiple sets of leg resistance exercise [14], and in young overweight men and women who performed an 84-minute cycling session (~3000 kJ) [15]. In agreement with the current study though, insulin sensitivity was not significantly improved in three other investigations in which adults completed 60–75 minutes of moderate intensity cycling, walking and/or rowing (~1250–2100 kJ) 12–17 hours before the postexercise testing was performed [16–18]. Thus, exercise volume and/or intensity are likely to be important, but not the only regulators of the magnitude and duration of insulin action response.…”

“…In Study 2, the exercise energy expenditure of ~1180 kJ during the 45-minute session was lower than typically used (~1250–3350 kJ) in prior single exercise session studies performed with adults [9, 13, 15–18, 34]. The lower exercise volume may explain the relatively modest improvement in glucose, insulin, and C-peptide AUC on the Same Day Ex trial and failure for the exercise to exert even a partial effect on the Prior Day Ex trial, or carbohydrate oxidation on either exercise trial.…”

“…In some [9, 13–15], though not all [16–18] previous human studies the effect of a single exercise session on insulin sensitivity was reported to last 12–48 hours. Notably, in all of those reports the postexercise measurement was performed at only one time point, so the time course of insulin sensitivity response has not been well described.…”

“…Further, it is clear that insulin resistance can be reduced by regular exercise even in obese or insulin-resistant people when performed over several weeks or months [8–12]. In adults, there is also evidence that the effect of a single exercise session on insulin sensitivity and glucose tolerance may last up to 48 hours [9, 13–15], although not all studies have been able to demonstrate this result [16–18]. This disparity in results may be due to differences among studies in the volume or intensity of exercise, the clinical or fitness status of the participants, or timing of the postexercise measurements.…”

Protective role of physical activity on type 2 diabetes: Analysis of effect modification by race–ethnicity

“…Among NHB and NHW women, Irwin et al reported similar decreases in fasting insulin levels for every 90 metabolic equivalent (MET)‐min/day change. Another study, conducted by Hasson et al, found no differences in the acute improvements in whole‐body S i comparing NHBs with NHWs following a single 75‐min bout of exercise at 75% V o 2 max. The results of these studies indicate that NHBs and NHW have similar physiological responses in the change in S i from PA.…”