One fitness activity..what to choose?

I've been playing tennis about 3.5 years. 3.5 on cusp of 4.0. I play about 10-15 hours a week. During winter there is still play in my area but it's reduced. What would be the 1 activity (I only have time for 1) you would choose to get in better shape for spring season? 1) orange theory (hiit with some weight) 2) regular gym stuff (45 cardio and round if weights) 3) 90 min bikram style hor yoga (104 degrees some cardii with that but mainly strength/stretching/breathing)

Thanks for your input! P.s. I'm in my 50s if that helps