Report

Plasma cytokine and exertional responses: exercise intensity and volume of exercising muscle mass

The smaller muscle cross-sectional area of the upper versus lower limb may act to augment intracellular signalling for IL-6 release per unit of contracting muscle when performing a given workload.

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

It is of interest, therefore, whether the upper limb may initiate an inflammation-mediating cytokine response at lower absolute and relative intensities than observed during lower limb exercise.

Methods

  • 12 recreationally active but upper-limb untrained males performed 30 min: i) low intensity (40% VO2peak) arm crank ergometry (ACE) (LOW); ii) moderate intensity (60% VO2peak) ACE (MOD); and iii) concurrent low intensity (40% VO2peak) ACE plus lower limb cycle ergometry to match total power output in MOD (HYBRID). Plasma concentrations of IL-6, IL10, IL-1ra, adrenaline and cortisol were determined at rest, immediately post-exercise, and 1 h and 2 h post-exercise. Heart rate (HR) and differentiated ratings of perceived exertion (RPE) were also recorded. This novel study aimed to further scientific knowledge supporting the prescription of regular physical activity and exercise involving the upper limb.

Main findings and applications

  • The major finding was that 30 min moderate but not low intensity ACE resulted in an IL-6 response associated with subsequent elevation in plasma concentrations of the anti-inflammatory cytokine IL-1ra.
  • This response occurred independent of sympathetic nervous system activation and at a lower absolute power output than previously observed during lower-limb exercise. • The absence of an additional plasma IL-6 response following HYBRID versus low intensity ACE alone suggests a greater intracellular signalling for IL-6 in the upper-limb performing an equivalent workload.
  • Differentiated RPE were higher for moderate versus low intensity ACE. Hence, a longer duration of low intensity exercise may achieve a greater inflammation-mediating cytokine response while managing peripheral strain in untrained individuals.
  • Further longitudinal research is required to maximise the anti-inflammatory potential of regular exercise employing the upper-limb via manipulations in the intensity and/or duration prescribed.

Reference

Paulson, T., Goosey-Tolfrey, V., Leicht, C. and Bishop, N. (2015). Plasma cytokine and exertional responses in relation to exercise intensity and volume of exercising muscle mass during arm-crank ergometry. Applied Physiology, Nutrition and Metabolism. 40(8): 782-787. DOI: 10.1139/apnm-2014-0537