def to_kcal(mets, weight):
    """
    Estimates energy expenditure in kilocalories/minute

    Ehrman, Jonathan K. ACSM's Resource Manual for Guidelines for Exercise Testing and Prescription. 6th ed. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins, 2010. Print.

    args:
        mets (float): MET value
        weight (float): body weight, given in kilograms

    Returns:
        float: kilocalories/minute
    """
    return mets * 3.5 * weight / 200
