The best way to increase muscular, tendon and ligament strength, as well as range of motion (ROM), is through eccentric strength training. The eccentric muscle action is most notably known for muscular growth, development, injury prevention, rehabilitation and soreness. There are some in the fitness / strength industry who argue that sprinting, jumping, cutting and various other dynamic movements, which mainly require powerful concentric muscular contractions, do not need to place much emphasis on the eccentric action; however, this cannot be further from the truth. Training the eccentric motion leads to a greater increase in overall strength and power.
Strength and power are needed to enhance all dynamic movements. The most favorable endocrine response, as a result of eccentric training, is an increase in strength of the tendons and ligaments; joints active ROM (particularly the knees); and collagen growth.
Injury rehabilitation and muscular development programs should focus on eccentric training (isometric as well). Two common injuries, for example, that benefit greatly from eccentric training are ACL and Achilles tendon injuries. Eccentric training has proven to increase strength and flexibility in the tendons and ligaments, which is necessary to rehabilitate and prevent ACL and Achilles tendon injuries. Another muscle(s), for example, that has shown significant benefit from eccentric training is the hamstring group. Injuries to the hamstring muscles are common in track, soccer, football, baseball, and lacrosse. Engaging in eccentric training for the hamstrings helps improved force capabilities while keeping the athlete healthy and playing.
Between muscles, ligaments and tendons, tendons are the hardest to heal because of limited blood flow. Blood flow promotes healing by carrying essential nutrients and vitamins to the injured body part, while removing unfavorable cells and tissue. Part of any rehabilitation program, or muscular correction program, involves the removal of scar tissue and the stimulation of new healthy tissue. Engaging in eccentric strength training will stimulate muscular growth / collagen* within the tendon.
Another superior injury prevention / rehabilitation methodology, next to eccentric training, is to train the mechanoreceptors. Mechanoreceptors are active signals in the cells that send sensory information from external stimulus to the brain. This allows us to stay balanced. Mechanoreceptor efficiency results in improved balance, coordination and strength. When one sustains an injury mechanoreceptor signaling is interrupted. Eccentric training, along with proprioceptive training, will help gain this efficiency back. Mechanoreceptor efficiency has a high correlation to injury prevention and rehabilitation. A common example of proprioceptive training is balancing on one leg or training on any unstable surface for that matter.
Joint ROM and increased sarcomeres (the basic unit of a muscle) result in greater levels of peak power around the joint because of an optimal muscle length-tension relationship. Optimal muscle length-tension relationships result in increased athletic performance and decreased injury risk. Resistance training that requires multiple joints to move through full ROM results in greater muscle length-tension relationships.
To state that more simple, increased sarcomeres as a result of large range of motion movements that require multiples muscles at once are the best exercises to enhance strength, power and thus athletic performance. However, taking a joint through a full ROM can often be difficult due to flexibility and technical difficulty. For example, most individuals perform parallel squats over full ROM squats because they are unable to squat through a full ROM. Therefore, individuals with flexibility restrictions need to focus their resistance training program on eccentric weight bearing exercises to increase flexibility / mobility.
Soft tissue health aids in full ROM capabilities thus allowing athletes to perform Olympic and power lifting more efficiently. For example, performing a full ROM squat activates the gluteal muscles better than a parallel squat; enhancing the glutes results in increased athletic performance (i.e. speed, jumping, power, etc…). Various studies have proven that full ROM squats lead to a decreased risk of injury (3, 4), particularly to the knee region, because it is a part of the endocrine response system to exercise stimulus. This results in increased tendon and ligament strength in and surrounding the knee. Increased joint ROM and muscle length-tension relationships will also lead to greater strength and technique in deadlifts, front squats, bench press and all Olympic movements.
Eccentric training results in the greatest amount of soreness. Consider all training volume, including sport specific training, when your performance program places emphasis on eccentric training. The best times to perform focused eccentric training are during off-season training; specific muscular development programs; muscular correction programs; and/or post-injury programs. The most common prescription for eccentric muscular action engages in a four second eccentric phase, followed by a one second concentric phase (1). I have also found that a four second eccentric phase, followed by a two second isometric phase and concluded with a one second concentric phase is advantageous when attempting to stimulate muscular growth, flexibility, rehabilitation and increased strength. The four-two-one, or as I call it “tempo” method of resistance training is extremely difficult to perform. However, the tempo methodology benefits include but are not limited to: enhanced muscular development; increased ROM; mobility enhancement; improved mechanoreceptor efficiency; stronger tendons and ligaments; and an overall healthier and enhanced athlete.
Eccentric training, or just simply controlling loads lifted when the force is being applied on you, is essential in muscular development, ligament health, core strength, power production and more!!
DEFINITIONS
*Collagen is a natural occurring protein that is mainly found in fibrous tissues (i.e. tendons, ligaments). Collagen accounts for approximately 25% of amino acids within the body. Collagen growth is vital for increased tendon and ligament strength.
SOURCES
1. NASM Essentials of Personal Fitness Training (3rd edition)
By, National Academy of Sports Medicine
Editors: Michael A. Clark, Scott C. Lucett and Rodney J. Corn
©2008
2. Preventive Effect of Eccentric Training on Acute Hamstring Injuries in Men’s soccer.
By, Petersen, J., Thorborg, K., et al.
American Journal of Sports Medicine. 2011. 39(11), 2296-2303.
3. http://functionalmusclefitness.com/squats-for-performance-range-of-motion-squats-vs-parallel-squats-part-i/