'WHY FITNESS YouTuber\'s ARE SO POPULAR | Bodybuilding This kills gains... Overtraining, sporadic or poor sleep patterns, lack of quality nutrition, excess alcohol, nicotine, caffeine, drug use and environmental stressors are all forms of stress that will cause the body to limit testosterone, GH and IGF-1 production, decrease insulin sensitivity in the muscle cells and in turn increase stress...'See also:
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