Definition of Functional Training:A classification of exercise which involves training the body for the activities performed in daily life.

Today's concept of "functional" training is not something I necessarily subscribe to as a fitness professional.
"Functional" Training?
I grew up skateboarding and snowboarding- two things that require an immense amount of balance, coordination and complete disregard for getting maimed. Skateboarding is not a common mode of transportation for the mainstream population, but in mastering the skill of simply rolling down the street on your board- I'd say you've mastered functionality.

In gyms across America, you will see folks balancing on Bosu balls, performing exercises on one foot and doing all sorts of interesting movements unrelated to daily tasks, yet trainers have their clients performing like circus monkeys all the while telling them it's all functional. Don't get me wrong, I'm a firm believer that you are only as strong as your weakest link. If you have no balance- then that is something you should strive to improve and build upon during your workouts. Never neglect doing what you aren't good at, or what makes you uncomfortable, for those are the things that will bring you the best results.

In my opinion, the best assessments of functional strength are the free Barbell Squat and Deadlift- two exercises you will rarely seen done in the gym. Go ahead, look around and count for me. Now look around and check out all the people crowding the machine and cable area in the gym- don't forget to look for the circus acts! I do believe that balance training has it's place in a workout, yet it all depends on many variables. What are your current abilities, weaknesses, strengths, etc?

After honestly assessing your abilities, design a workout program that will help you improve your weaknesses without completely ignoring your strengths.

The Barbell Squat (free barbell, not the Smith Machine), demands balance, coordination, flexibility and whole body strength. It doesn't get any more functional than that. I watch my 1 year old niece bend down to pick things up all day long, and her preferred functional exercise of choice? You guessed it, the SQUAT! That kid performs dozens of reps of quality squats all day long. Rarely do I see her stand on one foot and lean down to pick up her blocks. Her form is amazing too and she's self taught! Squats are instinctive from the time we are babies learning to crawl, walk, climb and run.

I have nothing against the Bosu ball, in fact I find it quite useful for several things in a workout. I'm also a big fan of adding one or two 1-legged activities into your workout to help stimulate the Cerebellum (the part of your brain responsible for balance and coordination). What I'm not so cool with is the integration of too much of this fancy stuff that has seemingly replaced real functional barbell movements. If I were stuck on a desert island, all I would need to stay in amazing shape is an Olympic Barbell with about 300 LBS of weight on it- and that's getting greedy. There's a reason the military still uses push ups, pull ups and sit ups as their preferred exercises- they are damn hard, and they deliver real results. Don't be fooled by the fluffy stuff, Old School exercises are what matter the most.