def percent_hrmax(vo2max_percentage):
    """
    Converts a VO2Max percentage into a maximum heart rate percentage 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:
        vo2max_percentage (float): percentage of VO2Max

    Returns:
        (float): estimated percentage of maximum heart rate
    """
    converted_percentage = vo2max_percentage * 100
    formula_result = (0.6463 * converted_percentage) + 37.182
    return formula_result / 100