Functional training is training your body for the specific sport you are involved in.
It has its origins in rehab where therapists developed exercises that mimicked what patients did at home or work in order to return to their lives or jobs after an injury or surgery.
The exercises used are mainly weight bearing activities targeted at the increased use of the core muscles of the abdomen and lower back.
Because most gyms and in fact trainers use and recommend weight machines which target and isolate specific muscles, there is a risk that your training may not necessarily bear any relationship to the sport of tennis.
Just think about it for a minute, why would you want to isolate a muscle group to work on it when isolation is not only impossible but not a reflection of what happens when you hit a forehand or a serve etc.
Because of this concept you need to start thinking about incorporating tennis training that works on the movements of tennis and not of particular muscles.
Just as an example, look at the video below. It shows a 4 position lunge.
The lunge is a great functional exercise for tennis as it is the type of exercise you would do on the court all the time!
Compare this to the leg extension that is so popular for leg training for many people - how often do you make that movement when you play??
NEVER (unless you kick your opponents!!).
For that reason alone the lunge wins BIG everytime and can be done loaded or just with your bodyweight depending upon your training level!
These type of exercises feature heavily in my Special Report on Tennis Strength which is available
HERE