Nutritional Support for Exercise-Induced Injuries


Injuries happen and nutrition is one of the methods to counter the negative impacts of an exercise-induced injury. Typically injury result in reduced activity and training. While some injuries are minor, such as a bruise or inflammation, others are much more debilitating such as a tear, broken bone, impingement, stress fracture or ruptured tendon. 

To minimize decline in muscle strength, neuromuscular control and overall fitness, nutrition plays a vital role in healing and rehabilitation process. It is possible to come back stronger and faster after the injury, following the right diet, physiotherapy and re-training program.

There are two main stages of injury:


Stage 1: Healing & Recovery

The first phase begins immediately after an injury. A complex process of wound healing begins which consists of three, phases:

  1. Inflammation
  2. Proliferation
  3. Remodelling

Inflammation caused by training is different than inflammatory response initiated by the injury. Athletes perceive inflammation as something bad, however while excess inflammation may be harmful, inflammatory process is essential for wound healing. Therefore attempting to drastically reduce inflammation may not be ideal for optimal recovery. Injured athletes should be careful when considering of the appropriate approach to managing inflammation.

The proliferative phase is when the wound is rebuilt with new tissue made up of collagen and extracellular matrix. There is an increase in protein synthesis for cell division following. As well as inflammatory process, this phase consumes a lot of energy.

Remodelling process is when the wound fully closes by the scar tissue formed as a result of the first 2 phases.


Stage 2: Rehabilitation & Hypertrophy

The second phase of complete recovery and returning to full function and training takes longer than the first, immobilization period. Sometimes it take several years to fully recovery from some injuries. Nutritional support is crucial to lessen the length of time and reduce the negative aspects of reduced activity and immobilization, as well as to support the return to activity and training.


Injuries that lead to reduced levels of activity have a lot of negative consequences. Disuse of a limb results in loss of muscle mass, reduced muscle strength and function. Substantial muscle loss has been reported in as little as 5 days of disuse (study link).

During muscle disuse, the basal, i.e. resting and fasted, rate of MPS (muscle protein synthesis) is decreased. Muscle loss is not the only negative consequence of inactivity in muscle tissue. Muscle mitochondrial oxidative function and metabolic flexibility are impaired with muscle disuse. Some of these changes occur as early as 48 h following initiation of inactivity. Moreover, simply reducing activity of muscle for 2 weeks may lead to decreased insulin sensitivity of muscle.

The single most important nutritional consideration during reduced muscle activity and/or immobility is to avoid nutrient deficiencies. Deficiencies of energy, vitamins, minerals and macronutrients—particularly protein— will impair wound healing and exacerbate loss of muscle and tendon mass and function. Nutritional choices made during recovery from an injury need to be carefully considered to optimize recovery and return to training.


Energy Balance


Energy intake is a critical component for optimal recovery from an injury. Athlete’s energy expenditure almost certainly will be reduced with a reduction in training and activity, therefore most athletes are likely make an intuitive conscious decision to drastically reduce energy intake to avoid increased body fat and total mass.

Energy expenditure following an injury with muscle immobilization is likely not be as greatly reduced as would be expected. During the healing process, energy expenditure is increased, particularly if the injury is severe. Energy expenditure may be increased by 15% up to 50%, depending on the type and severity of the injury. If athlete restricts the energy intake too much, recovery almost certainly will be slowed due to negative metabolic consequences. Negative energy balance will interfere with wound healing and exacerbate muscle loss. Therefore, instead of focusing on preventing weight gain, an athlete should ensure that sufficient energy is consumed during recovery from an injury.

 It is clear that negative energy balance has to be avoided, a large positive energy balance also is undesirable for optimal healing and recovery. A positive energy balance may be appealing to suggest during immobilization, even considering a small increase in body fat. However, there is evidence that a positive energy balance actually accelerate muscle loss during inactivity, most likely via activation of systemic inflammation. Moreover, excess energy with reduced activity leads to decreased insulin sensitivity and alterations in muscle and adipose metabolism.

Energy intake must be considered very carefully. Factors promoting satiety despite a reduced energy intake, including protein dose and type, in addition of low energy density food choices such as vegetables need to be considered as well. Energy balance should be the aim during reduced  inactivity and/or immobilization due to injury.


Macronutrients


Energy balance is not the most important factor to consider. The macronutrient composition of the energy is additional operative factor. Recent evidence suggests that oversupply of lipids (fats) decreases insulin sensitivity and impairs the response of MPS (muscle protein synthesis) to amino acids.

Protein

Insufficient protein intake impedes wound healing and increase inflammation to possibly deleterious levels. Synthesis of collagen and other proteins are very important in preventing muscle loss and supporting the healing processes. Sufficient protein intake is necessary to support wound and/or fracture healing.

Protein and amino acids probably have been the most widely studied nutrients in the context of muscle injuries. Recent studies has shown that athletes consuming relatively high protein intakes (~ 2.3 g protein/day/kg) had reduced muscle loss during periods of negative energy balance compared with lower protein intakes (~1.0 g/day/kg). Therefore we can assume that relatively high protein intakes (>2.0 g protein/day/kg), are necessary to prevent muscle loss. Also, more than ~30 g of protein in one sitting should be the maximum amount.

In addition, other factors in relation to protein should be considered. The pattern of protein intake in terms of timing and amount in each meal are the important factors.

Carbohydrates

Carbohydrates is the energy. Due to the limited physical activity, energy expenditure is reduced, therefore demand for the energy is reduced as well. It makes sense to slightly lower carbohydrate intake to prevent excessive weight gain. Prioritize higher-fiber, satiating foods such as whole grains, fruits and veggies. 

Fats

Omega-3 fatty acids has been used by many people because of its anti-inflammatory and immunomodulatory properties. Fish and flaxseed oil supplementation is often touted for reduction of inflammation.

The studies suggest that fish oil supplementation could play a role in the amelioration of muscle loss with disuse. However, high fish oil diets inhibited recovery of muscle mass during recovery from hindlimb suspension in rodents. Taken together, it seems that whereas high fish oil consumption may ameliorate muscle loss during a catabolic situation, it does not seem to be effective to enhance muscle hypertrophy. Moreover, the appropriate dose for injured humans has not been established.


 Micronutrients


There are no clear guidelines for use of micronutrients. Leucine, curcumin, and others have been demonstrated to be beneficial in rat studies. Higher intakes of these nutrients may do harm, therefore caution is warranted before recommendations for wholesale use of these nutrients by injured athletes. Deficiencies should be avoided, but supplementation above sufficiency does not help either.

Vitamin C is necessary for collagen formation.

  • Broccoli, Brussels sprouts, and cauliflower.
  • Green and red peppers.
  • Spinach, cabbage, turnip greens, and other leafy greens.
  • Sweet and white potatoes.
  • Tomatoes and tomato juice.
  • Winter squash.

Calcium and Vitamin D during healing from fractures is important for optimal bone formation.

  • Fatty fish, like tuna, mackerel, and salmon
  • Beef liver
  • Cheese
  • Egg yolks
  • Spinach
  • Kale
  • White & Soybeans beans

Vitamin A. It helps to form and maintain healthy teeth, skeletal and soft tissue, mucus membranes, and skin.

  • Beef liver
  • Cod liver oil
  • Sweet potato
  • Carrots
  • Black-eyed peas
  • Spinach
  • Broccoli
  • Sweet red pepper

Zinc. Maintains your immune system, supports cell division, cell growth, wound healing, and the breakdown of carbohydrates.

  • Oysters
  • Lean Sirloin Steak
  • Lamb
  • Hemp Seeds
  • Chickpeas
  • Black Beans
  • Cashews
  • Cheddar Cheese

Creatine is well studied supplement and widely used to enhance muscle gains during resistance exercise training. Creatine supplementation also has been shown to counteract disorders of muscle. However, there is no strong evidence for use of creatine to counter muscle loss during immobility. Creatine supplementation during weeks of lower-limb immobility did not lessen the loss of muscle mass or strength in healthy volunteers during 2 weeks of casting. However during rehabilitation after immobility, creatine supplementation resulted in an increased rate of muscle growth and strength gains compared with placebo.

Supplements that shown benefits:

  • Arginine
  • Collagen
  • HMB
  • Glutamine
  • Enzymes

Antioxidant compounds, including Omega-3,  decrease oxidative stress and have been recommended to improve healing and recovery.
High in antioxidants:

  • Curcumin from Turmeric/Curry Powder
  • Garlic
  • Bromelain from Pineapple
  • Cocoa & Tea
  • Berries

What to Avoid


  • Excess consumption of Omega-3 fatty acids. This could excessively depress the inflammatory response and compromise the wound healing.
  • Pro-Inflammatory foods. Processed foods high in saturated and trans fats, vegetable oils like corn, sunflower, soybean etc.
  • Excess energy consumption. This could lead to increased total and fat mass, especially if activity is dramatically reduced.
  • Alcohol. Alcohol impairs wound healing, by reducing the inflammatory response, and increases muscle loss during immobilization. It is very important to limit alcohol ingestion during recovery.
  • Salt. Over consumption can lead to calcium loss through urine.
  • Coffee. Too much caffeine (more than four cups of strong coffee a day) can slow down bone healing a little. A moderate amount of coffee or tea should be fine.

Summary


  • Deficiencies, particularly those of energy, protein, and micronutrients have to be avoided.
  • Be sure to keep up with your protein intake especially after exercise/rehab.
  • Energy balance is critical.
  • Higher protein intakes (~2–2.5 g protein/kg/day) may be warranted, and should be maintained even in the face of reduced energy intake.

Many athletes are afraid of gaining extra weight and feel they don’t deserve to eat calories or carbs when not expending calories through exercising. This is a common misconception, however, remember that your body still requires energy, carbs and nutrients – even at rest. In case of surgery, your daily energy demands may increase by 10-20%. Don’t be afraid of food and give your body building blocks to promote proper healing instead of dieting. Use this time to improve your lifestyle choices, learn new ways of cooking and create new meal planning strategies. Learn how to love your body in different shapes and sizes.


References

  1. Tipton, Kevin. (2015). Nutritional Support for Exercise-Induced Injuries. Sports medicine (Auckland, N.Z.). 45. 10.1007/s40279-015-0398-4.
  2. Tipton KD. Nutrition for acute exercise-induced injuries. Ann Nutr Metab. 2010;57:S43–53.
  3. Berardi, J. M. (2019, May 7). Nutrition for injury recovery: Food and supplements to speed up healing. Retrieved from https://www.precisionnutrition.com/nutrition-for-injury-recovery-infographic
  4. Tipton KD. Dietary strategies to attenuate muscle loss during recovery from injury. Nestle Nutr Inst Workshop Ser 813 2013;75:51–61.
  5. Wall BT, Morton JP, van Loon LJ. Strategies to maintain skeletal muscle mass in the injured athlete: nutritional considerations and exercise mimetics.
  6. Wall BT, Dirks ML, Snijders T, et al. Substantial skeletal muscle loss occurs during only 5 days of disuse. Acta Physiol. 875 2014;210:600–11

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