Here is a 7-day tennis fitness workout plan that you can follow:

Day 1:

• Warm up with a 5-10 minute jog or jump rope
• 3 sets of 12-15 reps of lunges, push ups, and squats
• 3 sets of 12-15 reps of shoulder press and bicep curls using dumbbells
• Cool down with some stretching

Day 2:

• Warm up with a 5-10 minute jog or jump rope
• 30 minutes of cardio, such as running or cycling
• 3 sets of 12-15 reps of tricep dips and lateral raises using dumbbells
• Cool down with some stretching

Day 3:

• Warm up with a 5-10 minute jog or jump rope
• 3 sets of 12-15 reps of lunges, push ups, and squats
• 3 sets of 12-15 reps of shoulder press and bicep curls using dumbbells
• Cool down with some stretching

Day 4: Rest day

Day 5:

• Warm up with a 5-10 minute jog or jump rope
• 30 minutes of cardio, such as running or cycling
• 3 sets of 12-15 reps of tricep dips and lateral raises using dumbbells
• Cool down with some stretching

Day 6:

• Warm up with a 5-10 minute jog or jump rope
• 3 sets of 12-15 reps of lunges, push ups, and squats
• 3 sets of 12-15 reps of shoulder press and bicep curls using dumbbells
• Cool down with some stretching

Day 7:

• Warm up with a 5-10 minute jog or jump rope
• 30 minutes of cardio, such as running or cycling
• 3 sets of 12-15 reps of tricep dips and lateral raises using dumbbells
• Cool down with some stretching

Remember to stretch before and after each workout to prevent injury. It is also important to listen to your body and take breaks when needed. Make sure to hydrate and fuel your body with healthy meals and snacks