There are many instances in daily life and sport, both expected and unexpected, in which muscular force must be exerted when in an unstable condition. Take for example, trying to stay upright after tripping on a flight of stairs or the surfer trying to remain upright after a wave has closed in on him/her. In such instances, one is often trying to balance on one leg or has the majority of their weight resting on one leg. In contrast, traditional bodybuilding exercises are performed on a stable platform, whether that be a seat, level floor or bench. Natural intuition leads one to question whether such exercises provide any benefit for movements performed on an unstable or unlevel platform.
Functional Training Basics
Functional training is a classification of exercise which involves training the body to perform better in both unstable circumstances and in everyday activities such as lifting and carrying. At the same time, functional training aims to minimise the risk of injury from everyday activities. More specifically, functoinal training focuses on training both 'stabilising' and 'primary movers' muscles as well as 'neutralizers', which serve to prevent unwanted movement during a given exercise. Functional training can also be applied to specific sports, with the aim of improving function and power in the specific movements and activities associated with a given sport.
Functional Training Theory
Functioinal training is built on the premise that traditional bodybuilding or powerlifting exercises, many of which use machines, focus on the development of muscle size at the expense of function. Overtime, repeated performance of such exercises can lead to disproportionate gains in the strength of prime mover muscles at the expense of stabilisers and neutralisers. Functional training recognises that many sports injuries on the playing field occur because a stabilising muscle was weak and stress was shifted to another muscle. Moreover, the weak muscles tend to be the same ones, namely, stabilisers of the hip, spine or scapulo-thoracic joint (i.e. shoulder joint). Therefore, one of the primary aims of functional training is injury prevention or reduction.
Functional training can be described as a continuim of exercises that teach individuals and athletes to handle their bodyweight in all planes of movement. Functional trainers often use bodweight as resistance and attempt to employ exercises that employ positions that make 'sense' to the individuals daily activities or sport-specific activities.
Take for example the average team sport, where players are in constant dynamic motion. Have you ever heard of an athlete pulling their hamstrings bilaterally (i.e. both at the same time)? Not a chance, right. Yet soo many of the popular leg exercises in the gym are performed using both legs, such as leg extensions, leg curls and leg presses. Herein lies the reason why functional training incorporates many one-legged exercises. This is because the muscles that support the lower leg during a single-leg stance - the quadratus, glute medius and adductors - are not nearly as active in double-leg exercises.
The same can be said for exercises such as the bench press. On the playing field, athletes are often required to fend off other players using a single arm, while in dynamic motion in an upright position. Contrast this with the traditional bench press performed in a supine position with back support and with two arms simultaneously. A more applicable 'functional exercise' might incorporate the use of dumbbells and perform alternating single-arm presses, focusing on form and stable, controlled movement.
Examples of Functional Exercises & Equipment
Functional training typically encorporates free-weights or cable-based weights that allow for free range of motion during a given exercise movement. Free weights and cables have the advantage of providing resistance not only in the vertical plance but throughout the range of and/or in the horizontal plane. Other common devices used as part of functional exercise include swiss balls, therabands (resistance bands), kettlebells, medicine balls, cyclone balls, BOSU balls, bodyblades, hanging cords (i.e. Redcord®) and others. Many of these devices serve to provide an unstable platform on which to perform a given exercise, thus requiring greater activation of stabilising muscles.
Advantages of Functional Exercise
As stated briefly above, one of the primary benefits of functional training is it's ability to minimize the risk of injury from everyday activities or sport-specific activities. Aside from building strength, functional training is also designed to improve balance and coordination. Functional training is a popular tool used by physical therapists to minimising discomfort from common complaints such as non-specific lower back pain. Whereas on the sporting field, functional training is popular for preventing serious injuries like anterior cruciate ligament tears. Michael Boyle, a high-profile US advocate for functional training and an author of two books on functional training, states in his most recent book5 that incorporation of functional training by the professional soccer players under his tuition has resulted in no ACL tears over the course of 6 years.
Supporting Research on Functional Strength Training
There have actually been studies comparing outcomes in terms of strength and balance from a free-weights based program versus a fixed-weight program. One such study found that when compared to fixed-weights, a free-weights program over a 16-week period resulted in a 115% increase in strength versus 57% and an increase in balance of 245% versus 49% for the fixed-weights program1.
Studies have also confirmed that free-weight exercises result in greater muscle activation when compared with the same exercise using a machine. One such study, compared muscle activation of the anterior deltoid, medial deltoid, and pectoralis major during a smith machine and free weight bench press. Results indicated greater activation of the medial deltoid on the free weight bench press than on the Smith machine bench press2.
In further proof of the extra stability required by free-weight exercises, a study which measured muscle activity in three chest-press exercises with different stability requirements (Smith machine, barbell, and dumbbells) found the dumbbell chest press required greater biceps brachii activation relative to the other types of chest-press exercises3. When doing a chest-press, the biceps brachii muscle serves to support the elbow and shoulder joints, and is referred to as the dynamic stabilizer.
Studies have also shown functional training can help with injury prevention in a number of sports. For example regular balance training using a balance board was found to reduce the incidence of ankle sprains in a group of volleyball players4.
Functional Strength Training Benefits
If you are an individual that has struggled with continued shoulder, knee or lower back injuries from your usual weight training regime, it might be timely for you to consider a model of weight training based more on the principles of functional training. Alternatively, if you are a competitive athlete, functional training is likely to be the best type of resistance training to help improve performance and prevent injury. One things for sure, functional training will continue to be a popular and effective alternative to traditional bodybuilding-type weight training
1. Spennewyn KC. Strength outcomes in fixed versus free-form resistance equipment. Journal of Strength and Conditioning Research. 2008;22(1):75-81.
2. Schick EE, et al. A comparison of muscle activation between a Smith machine and free weight bench press. Journal of Strength and Conditioning Research. 2010;24(3):779-84.
3. Saeterbakken AH, et al. A comparison of muscle activity and 1-RM strength of three chest-press exercises with different stability requirements. J Sports Sci. 2011;29(5):533-8.
4. Verhagen EA, et al. An economic evaluation of a proprioceptive balance board training programme for the prevention of ankle sprains in volleyball. Br J Sports Med. 2005;39(2):111-115.
5. Boyle M, 2010. Advances in Functional Training: Training Techniques for Coaches, Personal Trainers and Athletes. On Target Publications, Aptos.