Muscle mass and body temperature in the inflammatory response to upper-body exercise and heat

Chronic low-grade inflammation is associated with a range of chronic diseases, such as type 2 diabetes and cardiovascular disease.

Lead academic:
Professor Vicky Tolfrey
Additional academics:
Dr Christof Leicht
The Peter Harrison Foundation

This state is characterised by elevated resting levels of certain immune cells, like interleukin-6 and the inflammatory monocyte subtype. Regular exercise of sufficient volume can downregulate these levels, which is possibly one of the mechanisms in which exercise has a protective effect against the aforementioned diseases.

Although chronic low-grade inflammation is increasingly prevalent in the general population, possibly due to physical inactivity and diet composition, some populations are at an increased risk for this state (e.g. individuals with a spinal cord injury and the elderly); partly because their physical capacity does often not allow them to perform exercise of sufficient intensity to combat low-grade inflammation. This project investigates alternatives to do so in these at-risk populations. In addition, the mechanisms underlying the effectiveness of these alternatives will be studied, with a focus on the role of body temperature and active muscle mass.

Completed and ongoing research

  • The first study of this project showed that continuous moderate intensity arm-cranking and an interval protocol with 1 minute high intensity efforts interspersed with 1 minute active recovery are evenly effective in provoking a positive inflammatory response. Since this response to exercise is believed to be influenced by the increase in body temperature, passive heating could also induce part of this response. To investigate this, a project on the potential of hot water immersion to prevent or fight low-grade inflammation is currently underway. Lastly, the role of autonomic function and spinal lesion level in the inflammatory response will be studied with data collected during a wheelchair half-marathon in Oita (Japan).

Future work

  • The last part of this PhD-project will focus on the mechanisms underlying the inflammatory response to the health promoting strategies described in the previous section. In-vitro methods will be used to explore the effect of different temperatures and exercise responses in populations with distinct characteristics will be studied to gain more understanding into the role of muscle mass and training status. The accumulated knowledge of this project can later be used to inform future work to increase the effectiveness of health promoting strategies for individuals with a low physical capacity