Transcriptomic, proteomic and phosphoproteomic underpinnings of daily exercise performance and Zeitgeber activity of endurance training

Abstract

Timed physical activity might potentiate the health benefits of training. The underlying signaling events triggered by exercise at different times of the day are, however, poorly understood. Here, we found that time-dependent variations in maximal treadmill exercise capacity of naive mice were associated with energy stores, mostly hepatic glycogen levels. Importantly, running at different times of the day resulted in a vastly different activation of signaling pathways, e.g., related to stress response, vesicular trafficking, repair, and regeneration. Second, voluntary wheel running at the opposite phase of the dark, feeding period surprisingly revealed minimal Zeitgeber (i.e., synchronizing) activity of training. This integrated study provides important insights into the circadian regulation of endurance performance and the control of the circadian clock by exercise. These results are of high importance to understand circadian aspects of training design in athletes and the application of chrono-exercise-based interventions in patients.

Daily running enhances molecular and physiological circadian rhythms in skeletal muscle

“…Given the significant impact of genetically deleting both of the circadian repressors Cry1 and Cry2 on maximum treadmill running speed in mice [17], we hypothesized that maximum sprint speed may depend on the time of day. Others have reported that sedentary male mice exhibit enhanced sprint exercise capacity early in the night when CRY1/2 protein expression is lower [6] or at the dark to light transition [25]. However, we did not detect any significant impact of time of day on maximum sprint speed in sedentary c57BL/6J male mice (Figures 1B, 1C, and S1B).…”

The physiology of obesity: from mechanisms to medicine (M2M). Part one

“…This effect is not limited to the vagus: Chrobok et al (2022b) report that consumption of a high fat diet increases food intake during the day, blunts nucleus tractus solitarius rhythms in neuronal discharge and attenuates the response to metabolic neuropeptides prior to body weight gain. Maier et al (2022) find time-dependent variations in maximal exercise capacity in mice are associated with energy stores, and the timing of exercise results in activation of differing signalling pathways. In a complementary study, Vieira et al…”

The muscle clock: how does muscle physiology change in 24 h in response to exercise?

“…It is still unclear how the intrinsic muscle clock physiologically influences skeletal muscle molecular responses to exercise. In an exquisite and well-conducted study in this issue of The Journal of Physiology, Maier et al (2022) shed light on the associated regulation of exercise and the circadian cycle in skeletal muscle. Transcriptomic, proteomic and phosphoproteomic analyses indicate that different pathways are activated depending on the time of day.…”

“…Knowing that many proteins are regulated by phosphorylation, analysis of the phosphoproteomic pathway is an essential differential of this work. Maier et al (2022) identified that daytime exercise provides muscle glycogen savings. After exercising at ZT12, the specific muscle isoform of glycogen phosphorylase (PYGM) was phosphorylated at the Ser15 residue, capable of potentiating glycogen degradation, although muscle glycogen stores were consistently reduced by exercise.…”

“…Singularly, the study of Maier et al . (2022) indicates that physical activity at the optimal time of day could provide additional benefits for health and performance.…”