Table 1.

Summary of major molecular mechanisms induced by physical activity and skeletal muscle contraction that reduce the inflammation-insulin resistance state, improving brain and skeletal muscle health.

SKELETAL MUSCLE CONTRACTION
Physiological response	Effect
Production of IL-1ra, IL-6, IL-10	Reduced inflammation
Production of Adiponectin	Reduced Insulin Resistance
Activation of Nrf2	Reduced Oxidative Stress
Increased energy expenditure	Reduced Ectopic Fat

REGULAR PHYSICAL ACTIVITY
Physiological adaptation	Mediator	Major affected tissue
Production of kynurenine aminotransferase	PGC-1 α	Brain
Production of irisin	PGC-1 α	Brain/Skeletal Muscle
Mitochondrial biogenesis	PGC-1 α	Brain/Skeletal Muscle
Improved NMJ function	mBDNF	Skeletal Muscle
Hypertrophy	IGF-1, mTORC1	Skeletal Muscle

IGF-1: Insulin like growth factor-1; IL-10: Interleukine-10; IL-1ra: Interleukine-1 receptor antagonist; mBDNF: mature brain-derived neurotrophic factor isoform; mTOR: mammalian target of rapamycin; Nrf2: Nuclear factor erythroid 2-related factor 2; PGC-1α: peroxisome proliferator-activated receptor-gamma coactivator-1alpha; NMJ: neuromuscular junction.