experiencing lag while playing videos

Hi, I am using macbook air 2017(1.8 GHz Intel Core i5,8 GB 1600 MHz DDR3), now a days I am experiencing a lag while paying videos. The issue is strange as the video is lagging only after 5-10 mins and then if we touch the trackpad the video will play smoothly and again it lags after couple of minutes. I used quicktime, vlc, elmedia players but the same issue is happening(tried with different resolution videos). The lag is happening only couple of seconds, and this is irritating while watching movies and all. Please suggest a solution for the problem. Thanks in advance.