Acute continuous moderate-intensity exercise, but not low-volume high-intensity interval exercise, attenuates postprandial suppression of circulating osteocalcin in young overweight and obese adults.

Abstract

Bone remodeling markers (BRMs) are suppressed following the consumption of a meal. Our findings indicate that a single session of continuous moderate-intensity exercise, but not low-volume high-intensity interval exercise, performed 1 h after a meal attenuates the postprandial suppression of BRMs. Acute exercise transiently increases BRMs including osteocalcin (tOC) and the undercarboxylated form of osteocalcin (ucOC), a hormone that is implicated in glucose regulation. The effects of acute exercise and exercise-intensity on postprandial levels of tOC and ucOC are unknown. Twenty-seven adults that were overweight or obese (age 30 ± 1 years; BMI 30 ± 1 kg∙m^-2; mean ± SEM) were randomly allocated to perform a single session of low-volume high-intensity interval exercise (LV-HIIE; nine females, five males) or continuous moderate-intensity exercise (CMIE; eightfemales, five males) 1 h after consumption of a standard breakfast. Serum tOC, ucOC, and ucOC/tOC were measured at baseline, 1 h, and 3 h after breakfast consumption on a rest day (no exercise) and the exercise day (exercise 1 h after breakfast). Compared to baseline, serum tOC and ucOC were suppressed 3 h after breakfast on the rest day (- 10 ± 1% and - 6 ± 2%, respectively; p < 0.05), whereas ucOC/tOC was elevated (2.5 ± 1%; p = 0.08). Compared to the rest day, CMIE attenuated the postprandial-induced suppression of tOC (rest day - 10 ± 2% versus CMIE - 5 ± 2%, p < 0.05) and ucOC (rest day - 6 ± 4% versus CMIE 11 ± 2%, p < 0.05), and increased postprandial ucOC/tOC (rest day 3 ± 2% versus CMIE 15 ± 1%, p < 0.05). In contrast, LV-HIIE did not alter postprandial tOC, ucOC, or ucOC/tOC (all p > 0.1). Acute CMIE, but not LV-HIIE, attenuates the postprandial-induced suppression of tOC and ucOC. CMIE may be an effective tool to control the circulating levels of BRMs following meal consumption in overweight/obese adults.