Axial reloading during body weight unloading: Relationship between g-level and cardiorespiratory responses to running – A case study

•Changes in gravitational conditions leads to physiological adaptation.•Human locomotion is affected by gravity, such that locomotion changes have been observed between Lunar and Earth.•Lunar and Martian conditions can be simulated to study locomotion effects on Earth.•Countermeasures are required to support the optimal function of the human body.•These must be studied and evaluated in simulated conditions to understand compatibility.