I would say that depends on how many days per week you are working your legs with resistance training. Also, as stated above me you can change the intensity. I gave an example of what I do on the treadmill but you can also do it on a stationary bike, elliptical, ect and that changes the intensity.
Today my legs felt tired so I did a little different type of HIIT. I would do a two minute walk up hill followed by a 1 minute high speed jog (to the point where after a minute I NEEDED to stop). This IMO is easier on my legs than the 20 seconds SPRINT combined with the 1 minute slow jog.
Either way, it has been doing wonders for me since I started it so that is why I recommend it.