Get heart rate Garmin Connect IQ

function getHeartRate(am) {
    var heartRate = Activity.getActivityInfo().currentHeartRate;
    if (heartRate == null) {
        if (am has :getHeartRateHistory) {
            var HRH = am.getHeartRateHistory(1, true);
            var HRS = HRH.next();
            if (HRS != null && HRS.heartRate != ActivityMonitor.INVALID_HR_SAMPLE) {
                heartRate = HRS.heartRate;
            }
        }
    }
    if (heartRate != null) {
        return heartRate;
    } else {
        return "--";
    }
}

function getMaxHr() {
    try {
        var currentSport = UserProfile.getCurrentSport();
        if (currentSport != null) {
            var zones = UserProfile.getHeartRateZones(currentSport);
            if (zones instanceof Toybox.Lang.Array) {
                return zones[5];
            }
        }
    }
    catch (e) { }
    return 185;
}