Fitness influencers have become the most used advertising resource by the fitness industry to generate brand credibility through Instagram; social network that has established itself as the most convenient showcase to promote a healthy lifestyle based on exercise and balanced eating. The objective of this research was to identify the role that fitness influencers play in building brand credibility for young men, beginners or intermediate in some fitness discipline, through distorted imaginary of healthy life on Instagram. The methodology used for this study was qualitative, exploratory type. The results revealed that fitness influencers act as facilitators of brand credibility despite promoting a social imaginary where having a low percentage of body fat and a prominent muscle mass, driven by the abuse of synthetic substances, is a reflection of leading a healthy life.