Fitness relates to several life aspects, such as health and exercise. Because of its vast popularity, it is often referred to as a ‘fitness trend’ where the body has a central role. Due to technological advances, fitness has found its way into mobile applications and Social Network Sites (SNSs), prompting the linguistic analysis of these environments. This study investigates how female fitness is discussed by female personal trainers (PTs) online. A mixed approach of quantitative methodology (Corpus Linguistics) and qualitative textual analysis (Discourse Analysis) was adopted. Following Baker’s corpus-driven approach (2006), a specialised corpus was compiled with a total of 440 posts (51,779 tokens) from the Instagram accounts of three female professional PTs. Various patterns were presented under four themes: mind and body, physical strength, empowerment, and the FITNESS IS A JOURNEY metaphor. The most salient patterns discussed were health, aesthetics, weight-loss, and body-representation. There was strong evidence of other trends (‘fitspiration’, ‘HAES’, and ‘body positivity’) which promote a positive body image and strength (physical and mental) as a health indicator. In sum, the findings provide a female PT’s perspective on fitness and show how female fitness is promoted by encouraging positive narratives around fitness, the body and ourselves.