Leucintillskott i samband med träning stressar hjärtat och ökar proteinnedbrytning

[King Grub]

Observational studies have raised concerns that prolonged strenuous exercise training may be associated with increased risk of cardiac arrhythmia and even primary cardiac arrest or sudden death. It has been demonstrated that leucine can reduce prolonged exercise-induced muscle damage and accelerate the recovery process. The aim of this study was to investigate the effects of prolonged strenuous endurance exercise on cardiovascular parameters and biomarkers of cardiac injury in trained adult male rats and assess the use of leucine as an auxiliary substance to prevent the likely cardiac adverse effects caused by strenuous exercise. Twenty-four male Wistar rats were randomly allocated to receive a balanced control diet (18% protein) or a leucine-rich diet (15% protein plus 3% leucine) for 6 weeks. The rats were submitted to 1 hour of exercise, 5 d.wk−1 for 6 wk. Three days after the training period rats were submitted to swimming exercises until exhaustion and cardiac parameters were assessed. Exercising until exhaustion significantly increased cardiac biomarker levels and cytokines, glycogen content and inhibited protein synthesis signaling also led to cardiac electrical disturbances. When combined with exercise, leucine supplementation led to further increases in the aforementioned parameters and also significant increase in blood pressure and protein degradation signaling. We report, for the first time, that leucine supplementation not only does not prevent cardiac fatigue symptoms, but may also aggravate prolonged strenuous exercise-induced cardiovascular disturbances in trained rats. Furthermore, we find that exercising until exhaustion can cause cardiac electrical disturbances and cardiac myocyte damage.

Long-term leucine supplementation aggravates prolonged strenuous exercise-induced cardiovascular changes in trained rats. Exp Physiol, 17 May 2016.

http://onlinelibrary.wiley.com/doi/10.1113/EP085704/pdf

[1kg]

Hur kan leucine marknadsföras som "muskelökare" om detta nu är sant.

[BobaFett]

Hur kan leucine marknadsföras som "muskelökare" om detta nu är sant.

Det är det inte. Du måste titta på flera studier om ämnet för att kunna dra en slutsats. För varje studie som säger en sak finns det oftast studier som säger tvärtemot. Man får jämföra studierna för att se om det drar mer åt ett håll.

[exevision]

Sånt här får mig att ifrågasätta HMB som ju är en metabolit av leucin. Om nu leucin och bcaa är värdelöst så kan man ju fundera varför det skulle vara annorlunda med HMB. Speciellt nu efter Wilsons falska data (nu är det inte säkert att han förfalskat just studier om HMB).