func setupWorkout(_ workout: Workout) {
    stackView.arrangedSubviews.forEach { view in
        view.removeFromSuperview()
        stackView.removeArrangedSubview(view)
    }

    workout.workoutSegments.forEach { workoutSegment in
        let view = UIView()
        view.translatesAutoresizingMaskIntoConstraints = false
        let barView = UIView()
        barView.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(barView)
        let heightMultiplier = workoutSegment.highPower() / workout.maximumPower()

        barView.heightAnchor.constraint(equalTo: view.heightAnchor, multiplier: CGFloat(heightMultiplier)).isActive = true
        stackView.addArrangedSubview(view)
        let multiplier = workoutSegment.duration / workout.totalTime
        view.widthAnchor.constraint(equalTo: stackView.widthAnchor, multiplier: CGFloat(multiplier)).isActive = true
        barView.backgroundColor = workoutSegment.color()


        barView.bottomAnchor.constraint(equalTo: barView.superview!.bottomAnchor).isActive = true
        barView.leadingAnchor.constraint(equalTo: barView.superview!.leadingAnchor).isActive = true
        barView.trailingAnchor.constraint(equalTo: barView.superview!.trailingAnchor, constant: -1).isActive = true
    }
}