def percent_vo2(hr_percentage):
    """
    Converts a maximum heart rate percentage into a percentage of VO2Max based using the Swain conversion formula

    SWAIN, D. et al. (1994) Target heart rates for the development of cardiorespiratory fitness. Medicine & Science in Sports & Exercise, 26(1), p. 112-116

    args:
        hr_percentage (float): percentage of maximum heart rate

    Returns:
        float: estimated conversion to percentage of VO2Max
    """
    converted_percentage = hr_percentage * 100
    formula_result = (converted_percentage - 37.182) / 0.6463
    return formula_result / 100
