Exercise as a physiological intervention
When skeletal muscle contracts during exercise, it releases compounds called myokines, interleukin-6 produced by contracting muscle (not to be confused with the inflammatory IL-6 produced by immune cells), irisin, BDNF, and others, that produce systemic anti-inflammatory, metabolic, and neurological effects. This is one pathway by which exercise reduces systemic inflammation independently of weight loss: the contracting muscle is actively producing anti-inflammatory signalling molecules.
The anti-inflammatory effect of regular physical activity is not trivial. Sedentary individuals have significantly higher CRP, IL-6, and TNF-alpha than matched physically active individuals, not because they are diseased but because the anti-inflammatory myokine signal that physical activity provides is absent. This is why physical inactivity is not merely a risk factor for chronic disease but a direct physiological contributor to the systemic inflammation that drives it.
How different types of exercise affect different systems
Exercise and specific chronic conditions
In joint conditions, exercise reduces pain and improves function at every stage of osteoarthritis, with a dose-response relationship between exercise frequency and pain reduction. Resistance exercise rebuilds the muscular support that reduces mechanical joint loading. Aquatic exercise provides low-impact loading for patients unable to tolerate weight-bearing exercise. Joint pain is not a contraindication to exercise, it is a reason to exercise more carefully and specifically.
In metabolic disease, resistance exercise is the primary insulin-sensitising intervention. Post-meal walking reduces post-prandial glucose spikes more effectively than pre-meal walking. In type 2 diabetes, structured exercise produces HbA1c reductions comparable to some oral medications, without the side effects. For fatty liver, regular moderate exercise reduces hepatic fat independently of dietary change or weight loss.
In autoimmune conditions, regular moderate exercise reduces inflammatory markers and improves function in rheumatoid arthritis, contradicting the historical advice to avoid exercise during disease activity. The key is matching intensity to disease activity: gentle mobility and aquatic exercise during flares, progressive resistance during remission. Psoriasis helps improve with regular exercise through both inflammatory and metabolic mechanisms.
In cardiovascular disease, exercise reduces blood pressure, improves endothelial function, reduces arterial stiffness, lowers triglycerides, and raises HDL, addressing multiple cardiovascular risk factors simultaneously through a single intervention.
In neuro-fatigue conditions, exercise stimulates BDNF, brain-derived neurotrophic factor, which promotes neurogenesis, improves cognitive function, and reduces depression and anxiety. Low-intensity aerobic exercise helps improve mood, cognitive function, and quality of life in burnout, anxiety, and depression, even when it is the only intervention.
Exercise in CLCC care, matched to the condition and stage
In CLCC care, physical activity is a prescribed clinical intervention, not a generic recommendation to 'be more active.' The specific type, intensity, duration, and progression of activity is determined by the condition, its stage, the patient's current functional capacity, and the specific barriers to activity present in their case.
For patients with joint pain, physical rehabilitation is staged, beginning with range of motion and gentle loading before progressing to muscular strengthening. For patients with CFS or fibromyalgia, paced activity with strict energy envelope management is prescribed, never pushing through fatigue. For patients with metabolic disease, resistance exercise is prioritised over aerobic. For patients with cardiovascular risk, moderate aerobic activity is the priority alongside post-meal walking. The prescription is specific because the underlying drivers and the patient are specific.