metrics = GC.activityMetrics(compare=True)
n_activities = len(metrics)

GC.setChart(title='Lactate-Ramp',
            type=GC.CHART_LINE,
            animate=False,
            legpos=GC_ALIGN_TOP,
            stack=False)

for i, metric in enumerate(metrics):
    date = metric[0]['date']
    color = metric[1]
    print(color)
    x = list(GC.xdataSeries('Lactate-Ramp', 'Power', compareindex=i))
    y = list(GC.xdataSeries('Lactate-Ramp', 'Lactate', compareindex=i))
    if not (x and y):
        continue
    GC.addCurve(name=str(date),
                x=x,
                y=y,
                xaxis='Power',
                yaxis='Lactate',
                color=color,
                line=GC_LINE_SOLID,
                symbol=GC_SYMBOL_CIRCLE,
                size=3,
                opacity=100,
                opengl=False)

GC.setAxis('Power', min=90, max=350, type=GC.AXIS_CONTINUOUS)
GC.setAxis('Lactate', min=0.0, max=10.0, type=GC.AXIS_CONTINUOUS)