def zoladz(hrMax, adjuster):
    """
    Zoladz Method for target heart rate (THR) - derives exercise zones by subtracting values from HRmax. Results are +/- 5 bpm
    - Zone 1 Adjuster (easy exercise) = 50 bpm
    - Zone 2 Adjuster = 40 bpm
    - Zone 3 Adjuster = 30 bpm
    - Zone 4 Adjuster = 20 bpm
    - Zone 5 Adjuster (extremely tough exercise) = 10 bpm
    """
    return hrMax - adjuster
