Eccentric Exercise: Everything You Want to Know & More 2012 ACSM Health and Fitness Summit By Len Kravitz, Ph.D. and Aaron Bubbico, [email protected], www.drlenkravitz.com Suggested Reading: Bubbico & Kravitz. (2010). Eccentric exercise. IDEA Fitness Journal, 7(9), 50-59.

I. Eccentric exercise: Brief history A. In 1882 Adolf Fick observed that a contracting muscle under stretch could produce a greater force than a shortening (Lindstedt et al., 2001). B. Around 1932 A.V. Hill (Nobel laureate) discovered the body had a lower energy demand during an eccentric action (Lindstedt et al., 2001). C. In 1952, Abbott et al. stated: ‘When the force exerted on the muscle exceeds the force developed by the muscle it is referred to as negative work (because the muscle is absorbing energy in this motion). D. In 1953 Danish physiologist Erling Asmussen introduced the term eXcentric. ‘Ex’ means away from and ‘centric’ means center. II. Review of the physiology of muscle contraction and eccentric exercise: The interested reader is referred to the Eccentric exercise article (Bubbico & Kravitz, 2010) for a summary of this content A. Titin: largest protein known in the human body with over 27,000 amino acids. Molecular weight is 10x greater than the average protein. Very involved in passive tension in muscle. B. Review of the sliding filament mechanism (illustrated in Bubbico and Kravitz article) C. Why does an eccentric action develop more force than a concentric or Isometric action? 1) Many of the S1 units do not disconnect during the cross bridge binding; 2) Titin is activated in eccentric actions (creating force) (Herzog et al., 2008; Lieber, 2002) D. Eccentric actions in daily life. 1) Walking downhill: Energy absorbed can be dissipated as heat in muscle like a shock absorber, 2) Energy absorbed and recovered like an elastic recoil spring system. Stretch shortening cycle improves running economy and power (Lindstedt et al., 2001) III. Exercise-induced delayed-onset muscle soreness D.O.M.S. (also abbreviated DOMS) A. What is D.O.M.S.? Muscle soreness and swelling that becomes evident 8-10 hrs after exercise. Soreness peaks 24-48 hrs. Especially noticed after eccentric training. Takes up to 72 hrs for body to dissipate (Balnave et al., 1993). Theories of D.O.M.S. follow: B. Connective-tissue theory: Disruption of non-contractile components in (sarcoplasmic reticulum {SR}, connective tissue and sarcolemma) (McHugh, 2001). C. Cellular theory: Disruption of ‘Z’ line and ‘A’ band (McHugh, 2001). D. Excitation-contraction interference: Overstretched SR increases calcium ion release. Increased Ca++ causes protein filament breakdown (Proske & Allen, 2005). E. Theories of D.O.M.S. Eccentric exercise, overstretched/disrupted, contractile and non- contractile tissue damage, strain on sarcomeres, unrestrained release of calcium ions within the sarcomere, drop in contractile tension, DOMS, rise in passive tension F. Minimizing DOMS from eccentric exercise. Repeated bout effect (Proske & Allen, 2005). Eccentrically stimulate the target muscles (progressively) 1 week or more prior to a higher intensity eccentric bout. G. Repeated bout effect sequence/mechanism: 1st (lighter) eccentric exercise workout, DOMS, adaptation occurs (neural theory––increases in motor unit activity; connective tissue theory–– increases in connective tissue, cellular theory––addition of sarcomeres), repeat SAME bout of exercise (at higher intensity) ≥ 1 week later, less DOMS (major adaptation: sarcomeres) IV. Eccentric exercise research questions/topics/researchers follow: V. Is there a gender difference in DOMS after eccentric training? (Stupka et al., 2000). Very similar with genders, although some research suggests it is less in females. VI. Is there a different response of younger vs. older individuals from eccentric training? (Lavender & Nosaka, 2006). Investigated the response of 10 older (70 yrs) and 10 younger (19 yrs) males. Did 6 sets of 5 eccentric-exercise reps at 40% of 1-RM (also written 1RM). Younger men experienced more DOMS and had higher metabolic markers of DOMS (creatine phosphokinase). A. Why? Older group had slightly less range of motion; older adults may have better developed neural inhibitory mechanisms to avoid DOMS; with aging there is a loss of fast-twitch muscle fibers, which are challenged more by eccentric exercise. B. Also, no difference in older women and younger women in DOMS and muscular weakness from a 12-week study (knee extension/flexion) of concentric vs. eccentric training. (Ploutz-Snyder et al., 2001). VII. Is there a best way to introduce eccentric training to entry level clients? (Nosaka and Newton, 2002). Eight untrained males performed 3 sets of 10 repetitions at 100% of 1-RM in ONE elbow flexor…waited 4 weeks. Same men performed 3 sets of 10 repetitions at 50% of 1-RM with other arm. A. Muscles recovered but had much less DOMS in the 50% of 1-RM loading phase. VIII. Will eccentric training improve concentric strength? (Doan et al. 2002). 8 subjects did 2 separate days of 1-RM testing (2 days rest between days) on bench press. On third day (after 5 days rest) 4 subjects applied a 105% load on the eccentric load (5% greater than 1-RM) during the 1-RM and then immediately retested 1-RM (other 4 subjects did not add wt during eccentric phase). A. Increased their 1-RM by 5-15 lbs B. Why the increase in strength output? C. Neural stimulation from eccentric training causes a greater muscle spindle response, boosting concentric contraction force. IX. Is eccentric training useful for client rehabilitation? (Gerber et al., 2009). 40 subjects with ACL repair. 20 subjects did progressive eccentric training, wt. bearing functional eccentric training, and 20 subjects did progressive concentric overload, wt. bearing functional exercise for 12 weeks (3 weeks after surgery); 2-3 times per week A. Eccentric: greater increases in quadriceps femoris and gluteus maximus strength/function. B. Findings clearly demonstrate the effects of progressive eccentric exercise training in a comprehensive rehabilitation program. X. How does eccentric training effect metabolism? (Hackney, 2008). In 8 trained and 8 untrained college males, post-workout resting metabolic rate (RMR) was 8-9% elevated (for many hours) following a training session of 8 exercises (8 sets of 6 repetitions, 30-second rest between sets). First 3 sets very light weight. Performed a one second concentric and 3-second eccentric action. A. Excess postexercise consumption (E.P.O.C.). Oxygen consumed to bring physiological variables to resting level B. Eccentric exercise mechanisms for increase in RMR. Muscle trauma/injury, increase in creatine phosphokinase levels, muscle cell repair, protein synthesis, hormones recovery, restoration of catabolic and anabolic hormones XI. Is there a BEST way to do eccentric exercises? Best eccentric exercise practices include the following: Thorough full-body warm-up (5-10 min); Appropriate muscle/ preparation; One traditional warm-up set at 50% of what the client normally lifts. THREE METHODS Follow: XII. Eccentric emphasis training: a) Start with the weight client normally, b) For instance, if the client normally does a 8-RM, meaning she/he does 8 reps using a weight where he/she reaches ‘momentary muscular fatigue’ at 8 reps, c) Have client do the concentric contraction, lifting the load in a 1 second up, d) On the eccentric contraction, lower the load in 3-4 seconds (thus emphasizing the eccentric phase of the exercise), e) Client completes 8 repetitions (as this example is an 8-RM); the personal trainer will probably need to aid with the concentric lifts as the client starts to fatigue, f) Progression options: may increase time (i.e., 5-6 sec) during the lowering, eccentric emphasis phase: and/or vary the rep zones (4- RM, 6-RM, 10-RM, 12-RM, etc.), g) Number of sets is individualized to client goals. A. Exercise video demonstrations: single leg squat on incline leg press, dip on bench, back extension on Roman chair. XIII. Supramaximal training technique: a) Start with the weight the client normally uses for the particular muscular fitness goal, b) For instance, if the client normally does a 10-RM with 100 lbs., meaning she/he does 10 repetitions with 100 lbs (but cannot do an 11th repetition), c) With the supramaximal technique, start with 105% of what the client lifts; in this example the personal trainer would load the bar with 105 lbs, d) Help the client lift the weight in 1-2 seconds, e) Lower the load in 3-4 seconds, still emphasizing the eccentric phase of the lift, f) Progressively increase the supramaximal load (i.e., 107%, 109%, 111%, 113%...120%) as the client appears ready for greater eccentric training challenges; vary rep zones (4-RM, 6-RM, 10-RM, 12-RM, etc.), g) Number of sets is individualized to client goals A. Exercise video demonstrations: with personal trainer spotting, 5-RM bench press with 110% load (with spotter), 10-RM with 110% load (with spotter) XIV. Two up: One down eccentric training technique: a) The two up: one down technique is used with the arms and legs, b) Initially start with 40-50% of the weight the client normally uses for the particular muscular fitness goal being trained (overload progressively), c) For instance, if the client normally does a 10-RM with 100 lbs., meaning she/he does 10 repetitions with 100 lbs then you would start with 40% or 50% of that weight or 40 lbs or 50 lbs, respectively, d) With the two up: one down eccentric technique lift the weight up concentrically with both limbs and then lower the weight with one limb; repeat the concentric phase and lower with the alternating limb, e) Try to go up (concentric) with one second and lower (eccentric) with three seconds A. Exercise video demonstrations: leg extension, leg curl, heel raise XV. Let’s watch some eccentric exercises and answer some unique questions A. Exercise video demonstrations: bench press on smith machine (two up: one down), single arm and double arm triceps extension on physioball (eccentric emphasis), hack squat (two up: one down) XVI. Is it true that eccentric contractions use less energy then concentric actions? Even though eccentric contractions create more force than concentric actions, they use less energy. This is because during a concentric muscle action one molecule of ATP is used to detach each - cross-bridge. However, during an eccentric action some cross-bridges are forcibly detached due to the stretching of the muscle fiber, thus using less ATP (McHugh et al., 1999). A. Exercise video demonstrations: single arm (bench) press on physioball (eccentric emphasis), pull- up with leg raise (eccentric emphasis) XVII. Do most people get sore from eccentric exercise? Some clients feel more muscle ‘tenderness’ from (eccentric exercise) DOMS as opposed to muscle soreness. A. Exercise video demonstrations: biceps curl with Smith machine (two up: one down), 45-degree angle push-up on TRX© (eccentric emphasis) XVIII. Are there any other techniques that have been shown to reduce muscle soreness (besides he repeated bout approach)? The only scientific method of utilizing eccentric exercise with clients to markedly reduce DOMS is the repeated bout effect. No, just the repeated bout effect strategy. A. Exercise video demonstrations: supine pull-up on TRX© (eccentric emphasis), tuck and pike core in push-up position on TRX© (eccentric emphasis) XIX. If a client is injured, will eccentric exercise of the other limb be helpful? Yes, for injured clients, eccentric exercise of the ‘healthy’ limb is a viable option for cross training of the immobilized limb (that has been injured or recently had surgery) (Housh, 1998) A. Exercise video demonstrations: medicine ball abdominal training with personal trainer (eccentric emphasis), forward 45-degree angle triceps extension training on the TRX© (eccentric emphasis) XX. Does eccentric training help with exercise compliance? Submaximal loads have been shown to have much less DOMS, and thus, this may also improve the exercise compliance of the clients (Nosaka and Newton, 2002). A. Exercise video demonstration: (partial range) lowering with personal trainer (eccentric emphasis), hamstring (full range) lowering with personal trainer (eccentric emphasis) XXI. Is eccentric training potentially helpful for injury prevention? Yes, resistance exercise programs should include periods of eccentric exercise, as this will provide protection from injury or re-injury (Proske and Allen, 2005). A. Exercise video demonstration: dumbbell biceps curl series on physioball XXII. Do people get more fatigued from eccentric vs. concentric exercise? In some research, subjects report less fatigue from eccentric training as compared to concentric training. These findings support the importance of integrating eccentric training in personal training settings (Hortobagyi et al., 1996). XXIII. For optimal development of muscle strength and size, programs should include concentric and eccentric training (Proske and Allen, 2005).

References Cited: 1) Abbott, B.C. et al. (1952). The physiological cost of negative work. J of Phys, 117, 380-390. 2) Balnave, C.D. & Thompson, M.W. (1993). Effect of training on eccentric exercise-induced muscle damage. J of Appl Phys, 75 (4), 1545-1551. 3) Doan, B.K. et al. (2002). Effects of increased eccentric loading on bench press 1RM. J of Strength & Conditioning Research, 16(1), 9-13. 4) Gerber, J.P. et al. (2009). Effects of early progressive eccentric exercise on muscle size and function after anterior cruciate ligament reconstruction: A 1-year follow-up study of a randomized clinical trial. J of Phys Ther. 89(1): 52-59. 5) Hackney, K.J. et al. (2008). Resting energy expenditure and delayed-onset muscle soreness after full-body resistance training with an eccentric concentration. J of Strength and Conditioning Research. 22(5):1602-1609. 6) Herzog, W. et al. (2008). Mysteries of muscle contraction. J of Appl Biomechanics, 24, 1-13. 7) Hortobagyi, T. et al. (1996). Adaptive resp. to muscle length. and short. in humans. J of Appl Phys, 80(3), 765-772. 8) Housh, D.J., et al. (1998). Effects of unilateral eccentric-only dynamic constant external resistance training on quadriceps femoris cross-sectional area. J of Strength & Conditioning Research, 12(3), 192-198. 9) Lieber, R.L. (2002). structure, function, & plasticity (2nd Ed). Lippincott Williams & Wilkins 10) Lindstedt S.L. et al. (2001). When active muscles lengthen: Properties and consequences of eccentric contractions, News Physiological Science. 16, 256-261. 11) McHugh, M.P. (2003). Recent advances in the understanding of the repeated bout effect: the protective effect against muscle damage from a single bout of eccentric exercise. Scand J of Medicine & Science in Sports, 13: 88-97. 12) Nosaka, K., and Newton, M. (2002). Difference in the magnitude of muscle damage between maximal and submaximal eccentric loading. J of Strength and Conditioning Research, 16(2), 202-208. 13) Ploutz-Snyder, L.L, et al. (2001). Resistance training reduces susceptibility to eccentric-induced muscle dysfunction in older women. J of Gerontology, 56A, B384-B390. 14) Proske, U. and Allen, T.J. (2005). Damage to skeletal muscle from eccentric exercise. Exercise and Sports Science Reviews, 33(2), 98-104. 15) Stupka et al. (2000). Gender differences in muscle inflammation after ecc. exercise. J of Appl Phys, 89, 2325-2332.