remember if you are goin to modify just dont do too much activity cause injuries can occur from too much workout.... YOU DO NEED TIME TO RECOVER FROM SO MUCH ACTIVITY!!!! I love both Insanity and P90x...I started with Insanity then went on to p90x after and had amazin tennis results...now i have moved on to CLX, another beach body program and love it...but with all of them I made sure to take sundays off to recover and on mon wed and fri hit the tennis courts after i did my workout in the morning or afternoon for about a 2.5 hr court workout!!!
if you do follow the programs and put in the time with them your tennis game will go to higher levels!!!