Exercise-Induced Muscle Damage: Why Does It Happen? (And 5 Nutrition Solutions To Support Recovery)

Athletes train hard. They train almost every day, often twice a day, in order to be elite..

Does this mean athletes are constantly in a state of delayed-onset muscle soreness (DOMS) or fighting off excessive inflammation to effectively adapt to training to achieve their goals? Maybe. What about an athlete’s training phase, does that play a role? For example, if an athlete is optimizing for competition versus adapting to get bigger, stronger, or faster? 

What about recreational clients?

For many people, the sensation of mild to moderated delayed DOMS that creeps into your muscles 24-48 hours post-training is a sign of a good workout. You feel like you’ve trained and are making progress toward your goal. However, if it persists for more than 48 hours, if it limits your range of motion (ROM) or muscle function is it still helpful?

 Exercise-induced muscle damage (EIMD) is a complex and nuanced topic. 

A better question is when does exercise-induce muscle damage become so pronounced it requires specific nutrition strategies to mitigate the effects? I interviewed expert Dr. Daniel Owens PhD from Liverpool John Moore’s university to talk about his research in this area and what nutrition solutions you can turn to for evidence-based recovery support. 

First, let’s define exercise-induced muscle damage.

Listen to Daniel Owens PhD talk exercise-induced muscle damage on the Dr. Bubbs Performance Podcast!

Listen to Daniel Owens PhD talk exercise-induced muscle damage on the Dr. Bubbs Performance Podcast!

What Is Exercise-Induced Muscle Damage?

Exercise-induced muscle damage (EIMD) is characterized by symptoms that come on directly after training and persist for 1-5 days afterwards (although potentially all the way up to 14 days post-training). That’s a pretty wide margin, what happens if you get your training plan or recovery process wrong? 

For the athlete, the consequences of EIMD include is a direct effect on functional capacity (e.g. strength, range of motion, etc.), muscle soreness, muscle capacity and sense of force production and limb position.(1,2,3,4) How long and how intense these symptoms are for you depends on the intensity and duration of exercise and how your own individual susceptibility to the damaging stimulus of training.

For the athlete, loss of muscle function and increased muscle soreness likely have the greatest potential to negatively impact performance. 

Can targeted nutrition strategies help to offset these effects? Could this allow you to train more frequently or more intensely, thereby increasing the likelihood of achieving your goals? Or could it actually interfere with the recovery process? 

It’s a matter of balance; adequate training stress combined with sufficient recovery. Let’s take a deeper-dive into what causes exercise-induced muscle damage.

What Causes EMID?

Training of any type can cause exercise-induced muscle damage (EIMD), however there are a few types of training that may trigger greater muscle damage, such as; resistance training, prolonged or downhill running, and high-intensity interval training.(5,6,7,8)

Muscle damage is amplified during eccentric actions, particularly at longer muscle lengths, with greater forces, and faster angular velocities.(9,10,11) Interestingly, if you perform a training session with more eccentric loading, it may actually reduce the EMID in the subsequent sessions, a phenomenon known as the “rebound effect”. 

What are the underlying mechanisms that cause EMID? Let’s review.

#1 Primary Muscle Damage

Experts aren’t exactly sure the principle reason why eccentric training is more damaging to the muscle, however the consensus seems to be the mechanical loading during exercise.(12) Eccentric contractions have a lower motor unit activation compared to isometric and concentric contractions (when force is equal), putting an increased mechanical stress on a smaller number of muscle fibers during eccentric movements, and thus more muscle damage.(13)

#2 Secondary Muscle Damage

After the initial primary damage of training, a secondary effect occurs when calcium moves into cells, as the mitochondria attempt to maintain homeostasis.(14) The resultant inflammatory response is a crucial and natural process that clears away damage tissue, triggers tissue repair, and ultimately adaptation.

#3 Satellite Cell Activation

Muscle fiber recovery and regeneration requires the activation of muscle stem cells called satellite cells. Satellite cells are activated post-training, specifically in response to eccentric compared to concentric contractions.(15) The research highlights that sustained activation of satellite cells provides the muscle with the capacity to adapt more effectively from training.

To sum up, impaired muscle function, increased muscle soreness, elevated inflammatory levels and activation of satellite cells all play a role in exercise-induced muscle damage. 

What does all this mean for you the athlete?

 Nutritional strategies to target these areas - when used in the right context – may improve recovery from exercise-induced muscle damage. Let’s review five evidence-based nutrition strategies. 

Dietary Solutions for EIMD

Now you’ve understood the mechanisms underlying exercise-induced muscle damage (EIMD), you can better appreciate what nutritional interventions influence those mechanisms in order to exert a desired effect. 

There is a lot of nuance when it comes to application.

You don’t want to limit or buffer the exercise-induced stress and subsequent beneficial adaptations to training. The nutritional strategies we’ll discuss impact inflammation and oxidative stress – known to be important stimuli for adaptation - so it’s important to consider why you’re using them (i.e.  to cope with increased training volume and/or intensity) and when you’re using them (i.e. adaptation versus optimization phase).

The following are five potential evidence-based nutritional strategies.

#1 Protein

Protein is crucial to muscle protein synthesis and adaptation to resistance and endurance exercise.(16) Experts can’t say for sure whether protein around intense or damaging exercise can limit EIMD, but recent evidence suggests it can improve markers of muscle damage and accelerate recovery of force.(17,18) Aim for a protein intake of 0.2-0.5g/kg/meal around exercise, with bigger athletes trending toward the upper end of the range.

#2 Tart Cherry Juice

Dietary polyphenols are most commonly found in the diet via fruit, vegetable, tea and coffee consumption. Polyphenols have shown to exert significant antioxidant and anti-inflammatory effects, possessing the ability to attenuate cyclo-oxygenase (COX) 1 and 2 output to a similar degree compared to common, over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs).(19,20) 

In particular, tart cherry juice stands out from the pack when it comes to recovery.

Research in resistance training using heavy eccentric bicep curls combined with two servings of tart cherry juice per day found an accelerated rate of recovery and reduced muscles soreness.(21) 

A key benefit to using a “food first” approach to performance nutrition is that it’s unlikely to interfere with the primary muscle damage response from exercise and thus not limit positive adaptation to training (compared to supra-physiological doses in supplements). Where functional foods like cherry juice can exert its effect is during the secondary phase, when inflammation and oxidative stress ramp up post-training.

#3 Omega-3

Omega-3 polyunsaturated fats, specifically eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA), are important nutrients that exert anti-inflammatory effects. Omega-3 fats like EPA and DHA are found in highest abundance in cold, deep-water fatty fish (e.g. salmon, mackerel, anchovies, sardines, herring, etc.), seafood (e.g. oysters, mussels, etc.), grass-fed beef and nuts like macadamia and walnuts

Numerous studies have shown beneficial effects of omega-3 on inflammation, oxidative stress, and muscle function after intense exercise.(22,23,24,25)

Interestingly, there appears to be a “loading phase” of approximately two weeks to see changes in muscle omega-3 composition. A recent study found a highly effective loading protocol to be 5g/day dose of fish oil capsules (providing 3,500mg EPA and 900mg DHA), however this is much higher than the current recommendations.(26) Typically, a dose of 1,000-1,500mg (combined EPA/DHA) is suggested in athletes, however more research is needed in this area to confirm an ideal dose.

#4 Vitamin D

Vitamin D isn’t really a vitamin. In truth, it’s a seco-steroid hormone acquired by the body through exposure to the sun (e.g. ultraviolet B radiation or UVB). Sedentary lifestyles in the general population and athletes training indoors (or even outdoors in sun-shy athletes wearing skin covering apparel) has led to a large of number of athletes and active people being diagnose with deficient (< 30 nmol/L 25[OH]D) or insufficient levels of vitamin D. 

In the last decade, new technology has allowed for discoveries of the important effects of vitamin D on muscle function and performance.

Vitamin D is a potent regulator of the immune system and has shown to exert potentially important effects on athletic recovery; anti-inflammatory response post-exercise was found to correlate with the individual’s vitamin D levels, runners with low vitamin D exhibited increase inflammatory responses post-exercise, and athletes performing eccentric-concentric jumps on a plyo-press displayed faster recovery at higher vitamin D status.(27,28)

#5 Creatine

Creatine is keystone supplement in many athlete’s nutritional arsenal. However, many are unaware of the impacts of creatine on recovery. Creatine has shown beneficial effects on satellite cell number and muscle function post-training.(29)

DOWNLOAD THIS INFOGRAPHIC of EVIDENCE-BASED RECOVERY SOLUTIONS to inform your practice below…

DOWNLOAD THIS INFOGRAPHIC of EVIDENCE-BASED RECOVERY SOLUTIONS to inform your practice below…

The Bottom Line

Exercise-induced muscle damage is an important and natural phenomenon that triggers the positive and beneficial adaptations to exercise. In the general population, training stimulus and volume is unlikely to require additional recovery support beyond the nutrition fundamentals of adequate protein, omega-3 and vitamin D intake are likely all you need to support your training goals. 

In athletes, the stakes are much higher. Greater training volume and intensity, as well as two-a-day (sometimes three-a-day training in MMA athletes!) increases the need for the application of functional food strategies to support quicker recovery. 

As always, think about the typetiming, and total amount of the supplement, functional food, or nutritional strategy you’re implementing with clients and athletes.  

(Now get back to your training!)

Dr. Marc Bubbs ND, CISSN, CSCS

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References

1)    Byrne, C., Eston, R. G., & Edwards, R. H. T. (2001). Characteristics of isometric and dynamic strength loss following eccentric exercise-induced muscle damage. Scandinavian Journal of Medicine & Science in Sports, 11(3), 134–140.

2)    Marcora, S. M., & Bosio, A. (2007). Effect of exercise-induced muscle damage on endurance running performance in humans. Scandinavian Journal of Medicine & Science in Sports, 17(6), 662–671. 

3)    Twist, C., & Eston, R. G. (2009). The effect of exercise-induced muscle damage on perceived exertion and cycling endurance performance. European Journal of Applied Physiology, 105(4), 559–567. 

4)    Paschalis, V., Nikolaidis, M. G., Theodorou, A. A., Giakas, G., Jamurtas, A. Z., & Koutedakis, Y. (2010). Eccentric exercise affects the upper limbs more than the lower limbs in position sense and reaction angle. Journal of Sports Sciences,28(1), 33–43. 

5)    Burt, D. G., Lamb, K., Nicholas, C., & Twist, C. (2014). Effects of exercise-induced muscle damage on resting metabolic rate, sub- maximal running and post-exercise oxygen consumption. European Journal of Sport Science,14(4), 337–344. 

6)    Millet, G. Y., Tomazin, K., Verges, S., Vincent, C., Bonnefoy, R., Boisson, R. -C.,...Tarnopolsky, M. (2011). Neuromuscular consequences of an extreme mountain ultra-marathon. PLoS One, 6(2), e17059.

7)    Chen, T. C., Nosaka, K., Lin, M. -J., Chen, H. -L., & Wu, C. -J. (2009). Changes in running economy at different intensities fol- lowing downhill running. Journal of Sports Sciences, 27(11), 1137–1144. 

8)    Leeder, J. D., van Someren, K. A., Gaze, D., Jewell, A., Deshmukh, N. I.K., Shah, I., ... Howatson, G. (2014). Recovery and adaptation from repeated intermittent-sprint exercise. International Journal of Sports Physiology and Performance,9(3), 489–496. 

9)    Child, R. B., Saxton, J. M., & Donnelly, A. E. (1998). Comparison of eccentric knee extensor muscle actions at two muscle lengths on indices of damage and angle-specific force production in humans. Journal of Sports Sciences,16(4), 301–308. 

10)  Nosaka, K., & Sakamoto, K. E. I. (2001). Effect of elbow joint angle on the magnitude of muscle damage to the elbow flexors. Medicine and Science in Sports and Exercise, 33(1), 22–29. 

11)  Chapman, D., Newton, M., Sacco, P., & Nosaka, K. (2006). Greater muscle damage induced by fast versus slow velocity eccentric exercise. International Journal of Sports Medicine,27 (8), 591–598. 

12)  Proske, U., & Morgan, D. L. (2001). Muscle damage from eccentric exercise: Mechanism, mechanical signs, adaptation and clinical applications. The Journal of Physiology,537(Pt 2), 333–345. 

13)  Enoka, R. M. (1996). Eccentric contractions require unique activation strategies by the nervous system. Journal of Applied Physiology (1985), 81(6), 2339–2346.

14)  Ebbeling, C. B., & Clarkson, P. M. (1989). Exercise-induced muscle damage and adaptation. Sports Medicine, 7(4), 207–234. 

15)  Hyldahl, R. D., Olson, T., Welling, T., Groscost, L., & Parcell, A. C. (2014). Satellite cell activity is differentially affected by con- traction mode in human muscle following a work-matched bout of exercise. Frontiers in Physiology,5, 485. 

16)  Phillips, S. M., & Van Loon, L. J. C. (2011). Dietary protein for athletes: From requirements to optimum adaptation. Journal of Sports Sciences,29(Suppl 1), S29–S38. 

17)  Buckley, J. D., Thomson, R. L., Coates, A. M., Howe, P. R. C., DeNichilo, M. O., & Rowney, M. K. (2010). Supplementation with a whey protein hydrolysate enhances recovery of muscle force-generating capacity following eccentric exercise. Journal of Science and Medicine in Sport, 13(1), 178–181. 

18)  Nosaka, K., Sacco, P., & Mawatari, K. (2006). Effects of amino acid supplementation on muscle soreness and damage. International Journal of Sport Nutrition and Exercise Metabolism, 16(6), 620–635. 

19)  Seeram, N. P., Aviram, M., Zhang, Y., Henning, S. M., Feng, L., Dreher, M., & Heber, D. (2008). Comparison of antioxidant potency of commonly consumed polyphenol-rich beverages in the United States. Journal of Agricultural and Food Chemistry, 56(4), 1415–1422. 

20)  Wang, H., Nair, M. G., Strasburg, G. M., Chang, Y. -C., Booren, A. M., Gray, J. I., & DeWitt, D. L. (1999). Antioxidant and anti- inflammatory activities of anthocyanins and their aglycon, cyani- din, from tart cherries. Journal of Natural Products,62(5), 802. 

21)  Connolly, D. A., McHugh, M. P., Padilla-Zakour, O. I., Carlson, L., & Sayers, S. P. (2006). Efficacy of a tart cherry juice blend in preventing the symptoms of muscle damage. British Journal of Sports Medicine, 40(8), 679–683. discussion 683. 

22)  DiLorenzo, F. M., Drager, C. J., & Rankin, J. W. (2014). Docosahexaenoic acid affects markers of inflammation and muscle damage after eccentric exercise. Journal of Strength and Conditioning Research, 28(10), 2768–2774. 

23)  Gray, P., Chappell, A., Jenkinson, A. M., Thies, F., & Gray, S. R. (2014). Fish oil supplementation reduces markers of oxidative stress but not muscle soreness after eccentric exercise. International Journal of Sport Nutrition and Exercise Metabolism, 24(2), 206–214. 

24)  Jouris, K. B., McDaniel, J. L., & Weiss, E. P. (2011). The effect of omega-3 fatty acid supplementation on the inflammatory response to eccentric strength exercise. Journal of Sports Science & Medicine, 10(3), 432–438. 

25)  Phillips, T., Childs, A. C., Dreon, D. M., Phinney, S., & Leeuwenburgh, C. (2003). A dietary supplement attenuates IL-6 and CRP after eccentric exercise in untrained males. Medicine & Science in Sports & Exercise,35(12), 2032–2037. 

26)  McGlory, C., Galloway, S. D. R., Hamilton, D. L., McClintock, C., Breen, L., Dick, J. R., ...Tipton, K. D. (2014). Temporal changes in human skeletal muscle and blood lipid composition with fish oil supplementation. Prostaglandins, Leukotrienes and Essential Fatty Acids (PLEFA), 90(6), 199–206. 

27)  Barker, T., Martins, T. B., Hill, H. R., Kjeldsberg, C. R., Dixon, B. M., Schneider, & E. D. (2014). Vitamin D sufficiency associates with an increase in anti-inflammatory cytokines after intense exercise in humans. Cytokine, 65(2), 134–137. 

28)  Willis, K. S., Smith, D. T., Broughton, K. S., & Larson-Meyer, E. D. (2012). Vitamin D status and biomarkers of in ammation in runners. Open Access Journal of Sports Medicine, 3, 35–42. 

29)  Olsen, S. (2006). Creatine supplementation augments the increase in satellite cell and myonuclei number in human skeletal muscle induced by strength training. Journal of Physiology, 573(Pt 2), 525–534. 

 

 

Can Creatine Boost Your Physical (And Mental) Performance?

What is creatine? When most people hear the word creatine, they immediately think of high school or college-age jocks trying to get bigger and stronger. But creatine is far more than just a muscle-building supplement.

In fact, its benefits range from improved cognitive function, concussion prevention, autoimmune support and even improvement of some chronic degenerative conditions.

Not quite sure what creatine can do for you? Let’s take a closer look.

What is Creatine?

Creatine is a protein that is produced naturally in the body and is found in abundance in animal protein. It’s a high-energy molecule made up of three amino acids – arginine, methionine and glycine – that helps to produce ATP, the energy currency of every cell in your body. Without ATP, your cells would have no fuel and you wouldn’t even survive!

Animal protein is the best food source of creatine, such as grass-fed beef, wild game meats, ocean-fresh fish and free-range poultry. So, if you’re already following a Paleo approach to eating, naturally rich in animal protein, why would you need to add more creatine via a supplement? Adding a creatine supplement allows your body to store greater than normal levels of creatine in the body, thereby providing an added source of ATP to support your muscles and your brain. While these supra-physiological doses may not be exactly Paleo, there could be certain scenarios where you can get significant benefits.

Can Creatine Boost Your Performance In The Gym?

If you want to improve your performance in any sport, then improving your power, strength and lean muscle mass are key factors. Creatine significantly improves all of these areas, and then some.

Increasing your maximum strength is like adding more horsepower to your car’s engine; the stronger you are, the faster you run. Supplementing with creatine is proven to increase your max strength by 5-15%, which translates to more weight on your squat, deadlift or Olympic lifts. (1)

Creatine supplementation has also been shown to increase sprint performance, as well as endurance during repeated sprints. (2) This can help endurance athletes improve 5k, 10k and marathon times, cyclists upgrade time trial personal bests, and CrossFitters achieve superior WOD times.

If you want to add lean muscle, creatine has been proven to add 2-4 lb. of fat-free lean muscle in 4 to 12 weeks of training.(3) The muscle growth comes from the body’s capacity to increase ATP production from creatine supplementation, allowing you to train harder and recover faster. If you’re not wanting bigger muscles, simply modifying the dose can mitigate these effects.

The benefits don’t stop there. Creatine might just be the best “brain hack” out there!

Can Creatine Boost Performance at Work?

One of the most common questions I get asked by clients in clinical practice is, “How can I improve my mental focus and memory?” If you want to upgrade cognitive function, working memory and intelligence, then creatine may help unlock your true potential.

Creatine has shown significant promise as a potent brain-boosting nutrient. A study at the University of Sydney examined the effects of 6 weeks of creatine supplementation (5g per day) on memory and intelligence. (4) The researchers found those people supplementing with creatine had improved working memory, reduced mental fatigue and increased intelligence. That’s right, not only can you remember more details and maintain your focus for an increased number of hours, you actually get smarter, as well!

More and more research is coming down the pipeline uncovering creatine’s ability to boost brain function, focus and mental productivity. However, you can eat all the meat in the world, but your creatine stores cannot reach these supra-physiological levels without added supplementation.

Tempted to start benefiting from higher creatine and ATP levels in your body? Let’s take a look at whether this stuff is really safe.

Is Creatine Safe?

Anecdotal side effects of creatine often heard in the media include dehydration, cramping, musculoskeletal injury, gastrointestinal distress and kidney damage, yet the research does not support these claims.

While these side effects seem scary, none of this has been shown in the research studies. In fact, research on creatine supplementation of 10 months to 5 years found no negative effects on kidney function (5) and has in fact been linked with improving medical conditions such as brain and spinal cord injuries, muscular dystrophy, diabetes and high cholesterol.

With all the fad supplements out there, creatine is a proven and safe strategy for upgrading your health and your performance. Let me walk you through the approach I typically recommend to my clients.

How Much Should I Take?

If you want to boost your performance in the gym and at work and give creatine a try, here is the best way to start. For men, add a 5g serving every day with a meal; for women, 3g per day. Creatine monohydrate is the most cost-effective form and actually the type they use in all the research studies, so save yourself a few dollars and forget the expensive creatine with supposed “bells and whistles”.

The highest dietary source of creatine is herring, followed by red meat, however this only saturates the tissue to approximately 90%. The addition of a supplement take this to 105-110% saturation, thus providing the brain and body benefits. For vegetarians and vegans, tissue levels hover around 70%, so the addition of a supplement can be even more beneficial.

You can add a powder form (make sure it has no added sugar) into some water and drink it; just be sure to eat a meal at the same time, as elevated blood sugars and insulin help improve absorption. You can also opt for capsules, but it’s a lot of pills to take on a daily basis (typically 6 x 500mg for women and 10 x 500mg for men).

Continue for 8 weeks and see for yourself how you look, feel and perform. If you’re satisfied with your results, you can discontinue it. The washout period for creatine levels to return to pre-supplement baseline is about 30 days. If you want to continue, the research shows you can maintain your dose for 6-12 months, if desired. However, periodic tapers of 2-3 weeks is recommended every 2-3 months.

Just remember that creatine isn’t a quick fix. You still need to eat real, whole food, train properly and get quality sleep if you want to improve brain function and body composition. If your diet and lifestyle are junk, creatine isn’t going to help much.

Dr. Marc Bubbs ND, CISSN, CSCS

Want to learn more? Listen to expert strength coach Keith Norris talk "Mindset Hacks & How To Look Good Naked" on the Dr. Bubbs Performance Podcast...