In overweight men, taking L-leucine supplements along with sprinting increases levels of IL-6 and IL-1β, which reduces the anti-inflammatory effect seen when sprinting is done without the supplement.
Mechanism
Synthesis from 1 study
Taking L-leucine before sprinting turns the body's natural anti-inflammatory response into a pro-inflammatory one by boosting certain inflammatory signals. This blocks the calming effect of exercise, keeping inflammation high and reducing the feeling of fullness after working out.
Most probable mechanism
When a person takes L-leucine before sprinting, the supplement activates immune and fat cells to release more inflammatory signals like IL-6 and IL-1β. These signals block the natural anti-inflammatory response that sprinting usually triggers, preventing the body from calming down inflammation and reducing appetite control.
L-leucine activates mTORC1 signaling in immune cells and adipocytes, increasing transcription of pro-inflammatory cytokine genes
L-leucine enhances TLR4 signaling in adipose tissue, triggering NF-κB activation and release of IL-1β and TNF-α
Sprint exercise alone induces IL-6 release from skeletal muscle, which stimulates hepatic and adipose production of IL-10 to establish an anti-inflammatory balance
Elevated IL-6 and IL-1β from L-leucine supplementation suppress IL-10 production and lower the IL-10/IL-1β ratio, shifting the cytokine balance toward pro-inflammation
The pro-inflammatory cytokine profile blunts the anti-inflammatory signaling normally induced by sprint exercise, preventing suppression of orexigenic pathways and reducing satiety enhancement
Evidence from Studies
Supporting (1)
Community contributions welcome
Contradicting (0)
Community contributions welcome
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.