Is your goal to hit each muscle group once a week?
Or are you just winging it and having fun?
Once a week? You must think I am slacking...
If I started on a Monday this is what it would look like:
Monday: Chest / Bi's (Then the few sets of legs & stomach with treadmill)
Tuesday: Back / Tri's (Then the few sets of legs & stomach with treadmill)
Wednsday: Chest / Bi's (Then the few sets of legs & stomach with treadmill)
Thursday: Back / Tri's (Then the few sets of legs & stomach with treadmill)
Saturday: Chest / Bi's (Then the few sets of legs & stomach with treadmill)
Sunday: Back / Tri's (Then the few sets of legs & stomach with treadmill)
That is why I need to work shoulders in. That gives each major muscle two days to recoup instead of just 1. That is how I use to do it back in the day. Although now it is more about lower weight (Still to exhaustion on lots of sets) & higher reps.
I would be lying though if I said I did not hit 2 days of rest this week, but that is OK too. But above is the goal with shoulder added in there as their own day.
Have you thought of making the legs (largest muscles in the body!) a separate group?
Another technique is to superset opposing muscle groups.Supersets
Supersets are an advanced bodybuilding technique in which you perform a set of two different exercises back-to-back. According to MuscleandStrength.com founder Damien Mase, the exercises you choose for supersets must be close together on your body, such as triceps and biceps or hamstrings and quadriceps. Once you have chosen two exercises, perform a full set of one followed immediately by a full set of the second. This combination of exercises forces more blood into the target muscles and will cause you to reach muscle exhaustion quickly
Great for workout efficiency and plateau breakthroughs.
This also allows for maximum rest and twice a week training of all muscle groups.
Monday- Chest & back (always do before 'arm' day).
Tuesday- Legs & shoulders.
Wednesday- Bi's, Tri's and forearms
(especially for you tennis players!
Thursday- Rest or repeat cycle.
From there you can add your cardio and core training as necessary.
Sounds like you're on the right track by keeping the weight down, reps up, and working the muscles to exhaustion. The last thing you want to do (for your tennis) is limit flexibility and develop muscles trained to function in only linear movements.
Good luck and have fun!