News & Views from the Editor-in-Chief: Andrew M. Jones
In this month's edition of News & Views I have chosen to highlight two quite different, but equally important, articles.
In 'Mechanisms of Neuromuscular Fatigability in People with Cancer-related Fatigue', Brownstein and colleagues assessed the etiology of fatigability in people with post-treatment cancer related fatigue. Ninety-six people were dichotomized into two groups (fatigued and non-fatigued) based on a clinical cut-point for fatigue. Alterations in neuromuscular function in the knee extensors were assessed across three low-intensity stages (0.3, 0.6 and 0.9 W·kg-1) of an incremental cycling test. The fatigued group demonstrated a substantially more pronounced decline in neuromuscular function, with reductions in muscle force up to five-fold greater than the non-fatigued group. The greater reductions in resting evoked twitch responses in the fatigued group suggests that their greater fatigability was a result of intramuscular perturbations. Such a rapid decline in neuromuscular function has potentially important implications for the physiological and perceptual impact of typical daily physical activities.
Genetic differences among us partly explain the degree to which we enjoy and engage in physical activity (PA). Genetic variants associated with PA behavior have begun to be identified and it is now possible to identify genetic variants related to our motivation for and enjoyment of different PA types. In 'Genome-wide Association Study of Liking for Several Types of Physical Activity in the UK Biobank and Two Replication Cohorts', Klimentidis and colleagues performed genome-wide association studies of liking for five types of PA (bicycling, exercising alone, exercising with others, working up a sweat, and going to the gym) in over 157,000 individuals, and identified 19 associated genetic markers. Genetic correlation and polygenic score analyses showed that liking of PA could capture additional and distinct dimensions of PA behavior that are not captured by either self-report or accelerometry. These genetic factors could provide insight into the mechanisms underlying PA behavior, potentially help plan more effective interventions to improve PA habits, and bridge gaps that may exist between liking and engaging in PA.
Andrew M. Jones
University of Exeter