TRAINING
Eccentric Resistance Training
How the eccentric action of strength training can benefit daily activities BY HELEN VANDERBURG MAURICIO LOZANO DEL VALLE Co-owner of The ACADEMY powered by Heavens in Calgary, AB, internationally renowned fitness educator, instructor, and trainer of trainers. THEACADEMY_Y YC
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esistance training has gained tremendous popularity among fitness enthusiasts. The benefits of strength training are highly researched and indicate the importance for a wide range of goals and needs from increased function for daily life to sport performance, rehabilitation, and weight loss. Resistance training, also known as strength training or weight training, is a method of training against an external force to gain strength, power, and muscle size. There is a wide variety of methods and philosophies of training based on goals and outcomes, but new research is shedding light on the benefits of eccentric resistance training. To understand these benefits, let’s begin with a brief review of muscle physiology. Muscle contractions are grouped into two categories, isometric or isotonic. Isometric contraction of a muscle generates tension without changing length. An example is holding a dumbbell halfway up in a biceps curl, like carrying your groceries! The muscles generate sufficient force to prevent the object from being dropped. Isotonic contractions can be eccentric, the lengthening of the muscle under tension, or concentric, the muscle shortening under tension. As we move, muscles provide both positive and negative external work. Positive work is a result of concentric muscle action, muscle tension is sufficient to overcome the load, and the muscle shortens as it contracts. This force occurs when the force generated by the muscle exceeds the load opposing the contraction. Negative work is when the muscle acts to decelerate the joint or otherwise control the repositioning of the load and protects the joints structure from damage. This is eccentric action. For example, the lifting phase in a biceps curl is the concentric action, while lowering is the eccentric action. In natural movement or locomotion, the muscle contractions are multi-faceted as they can provide changes in length and tension in a time-varying manner. Strength training involves both eccentric and concentric contractions to move the resistance.
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An emphasis on the eccentric-muscle phase of the movement in resistance training is being researched and shows positive results in speeding recovery and rehabilitation of weak or injured tendons. According to the research, the energy cost of eccentric training is very low, while the magnitude of the force produced is unusually high. Therefore, muscles respond to eccentric training with meaningful changes in strength, size and power. Muscles are stronger eccentrically than concentrically, which means you can lower a load with greater strength than lift a load. For example, doing a pull-up is a challenging exercise; however, it is easier to lower from the top of the pull-up than it is for the pulling phase. By practising the lowering you will gain strength to accomplish the pull-up. A simple way to bring eccentric training into your resistancetraining workout is to spend two to three times longer on the eccentric phase than the concentric phase of the exercise. For example, you may lift the weight concentrically for a tempo of one to two seconds and lower the weight, eccentrically for a tempo of three to six seconds. This increases the time the muscle is in a state of contraction—referred to as time under tension when training. The movements of daily life require eccentric control to decelerate the momentum of the body’s movement. Training eccentrically will give you more strength for everyday activities such as walking downstairs or downhill, or in sports such as pickleball and tennis where it requires you to stop and start frequently with changes of direction. However, the research concludes that eccentric and concentric action are both very effective and important for optimal development of muscle strength and size, and resistance training programs should include concentric, eccentric, and isometric training. Ideally you should vary your strength-training program periodically for the best results.