By Kristin Duyn, MSc

Injuries are an inescapable aspect of exercising and participation in sport. Injuries typically result in cessation, or at least a reduction, in participation in sport and decreased physical activity. More severe injuries may result in immobilization of a limb. Recent evidence suggests that half of the total number of injuries can be considered severe, leading to an average of >3 weeks without training or competing [1]. Thus, interventions that can increase the rate of healing and decrease the time to return to play are important. Among other options used by trainers, physicians and athletes, nutritional support has widely been shown to help enhance recovery. 

With regards to nutrition, when an athlete becomes injured we focus on three main goals:

1) Inflammation support and management

2) Immune support

3) Regeneration and anabolic support

INFLAMMATION

Regardless of the type of injury, there’s usually damage to muscle, bone, and vascular tissue.  When these tissues are injured, they’re deprived of their normal flow of oxygen and nutrient-rich blood. Reduced blood flow, as well as the actual physical damage, leads to cell death [2]. Treating acute injuries requires a tricky balance of managing inflammation while allowing it do its important job. While managing inflammation in the early stages, we want to reduce pain, as this can cause biomechanical compensations and changes that may lead to secondary injury [2].

However, again, strategies that eliminate pain often target inflammation. 

Dietary fat for inflammation control

The ratio of omega-6 to omega-3 in the diet is important for overall inflammation in the body — especially during normal periods of healthy living when we definitely want to keep inflammation under control. In these circumstances, the omega-6 to 3 ratio should be anywhere from 3:1 to 1:1, which should lead to a balanced inflammatory profile [3]. 

However, during an injury cycle, it is ideal to purposely decrease omega-6 fats and increase omega-3s (specifically fish oil).  High omega 6:3 ratios reduce collagen production while a low 3:6 ratio supports healing.  It is recommended injured athletes take a range of 3-9 grams of fish oil (salmon oil, sardine oil, menhaden oil, krill oil, etc.) per day [3].

To balance the fats in your diet, Increase intake of olive oil, mixed nuts, avocados, flax oil, ground flax and other seeds, etc. Get some of each fat source each day. These foods will balance out the saturated fats naturally present in your protein sources, leading to a healthy profile.

Turmeric 

A flowering plant in the ginger family, turmeric has long been used as an anti-inflammatory agent and in wound healing. Current research shows that the active ingredient, curcumin, is responsible for some of the benefits of turmeric. While adding turmeric to food every day is a good strategy, using 400-600 mg of supplemental turmeric extract 3x per day (or as described on the product label) is probably more manageable for most people [3]. 

Bromelain

Bromelain is another anti-inflammatory plant extract from pineapple. While best known for its digestive properties, bromelain is an excellent anti-inflammatory and analgesic compound although its mechanism of action is poorly understood. Typically bromelain is given in doses of 500-1000 mg/day for the management of inflammation [3].

Flavonoids

Found in cocoa, tea, red wine, fruits, vegetables, and legumes, flavonoids have been shown to help manage inflammation through their antioxidant actions [3].  Focus on foods rich in natural inflammation-modulating agents such as curry powder, turmeric, garlic, pineapple, cocoa, tea, and blueberries.

ENERGY INTAKE

During the healing process, energy expenditure is increased, particularly if the injury is severe [1]. Energy expenditure may be increased by 15 % up to 50 %, depending on the type and severity of the injury. Thus, whereas reduced physical activity and training may result in reduced total energy expenditure, the overall reduction may be less than appears obvious. 

An effort to attain energy balance during recovery from injury is critical. If restriction of energy intake is too severe, recovery almost certainly will be slowed due to negative metabolic consequences. Negative energy balance will interfere with wound healing and exacerbate muscle loss [1]. MPS is an energetically expensive process. It has been estimated that a well-muscled male expends ~500 kcal a day on MPS even without the consideration of physical activity [1].  

Protein Intake

 Athletes who regularly consume high amounts of protein (>2g/kg) had reduced muscle loss during periods of negative energy balance than those at a lower end [1]. In healthy athletes 20-25g maximally stimulates mTOR (which promotes anabolic processes), but may need more due to anabolic resistance. Absorption and utilization is maximized if spread equally through the day [1]. 

The response of MPS to protein ingestion stems from the essential amino acid  (EAA) content of the protein i.e. nonessential amino acids are not necessary for maximal stimulation of MPS [1]. Thus, EAA supplementation has been recommended for amelioration of muscle loss during muscle disuse following injury [1]. The potential for EAA supplementation to ameliorate muscle loss during disuse may be attributed to the branched-chain amino acid leucine. Leucine has been shown to restore impaired muscle protein synthesis during immobilization [2]. Whey protein from dairy sources provides a high dose of leucine [2].

Micronutrient needs during recovery

Vitamins A, B, C, and D as well as calcium, copper, iron, magnesium, manganese, and zinc are all important for injury recovery. (Interestingly, vitamin E may slow healing so avoid vitamin E supplements during injury.

Vitamin A

Vitamin A enhances and supports early inflammation during injury, reverses post-injury immune suppression, and assists in collagen formation via collagenase modulation. Studies have shown that collagen cross-linkage is stronger with vitamin A supplementation and repair is quicker [3].

Vitamin C

Vitamin C enhances neutrophil and lymphocyte activity during phase 1 of acute injury. It also plays an important role in collagen synthesis, as it helps form bonds between strands of collagen fiber [2]. With vitamin C deficiencies, collagen fibers are formed abnormally and fibrous tissue is weak with poor adhesion [3].

Vitamin C is also a powerful antioxidant and immune system modulator, and research suggests that vitamin C can help people recovering from surgery, injury, and ulcers. [3]. 

Copper

Copper is a mineral that assists in the formation of red blood cells and works with vitamin C to form elastin and to strengthen connective tissue. 2-4 mg/day is recommended during the first few weeks of injury repair [3].

Zinc

Zinc is required for over 300 enzymes in the body and plays roles in DNA synthesis, cell division, and protein synthesis — all necessary for tissue regeneration and repair.

Here’s a brief list of the vitamin and mineral supplements that help with acute injury recovery: [3]

• Vitamin A – 10,000 IU/day for 2-4 weeks post-injury
• Vitamin C – 1000-2000 mg/day for 2-4 weeks post-injury
• Copper – 2-4 mg/day for 2-4 weeks post-injury
• Zinc – 15-30 mg/day for 2-4 weeks post-injury

Calcium & Vitamin D

Moderate supplementation of 800mg of calcium in conjunction with Vitamin D has been shown to improve markers of bone health in athletes. For females with recurrent bone injuries, increasing supplement dose to 1200-1400mg may be recommended [2]. It is well researched that maintaining a sufficient level of Vitamin D is beneficial for both bone and extra-skeletal health [2]. 

Conclusion 

Continual, repetitive stress faced by endurance athletes makes injury almost inevitable. The key to disrupting this cycle and preventing injury is to develop a protective routine focused on adequately fueling your body, preparing for and recovering from intense workouts. By incorporating these techniques, you can minimize your risk of injury as you train hard this summer.

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References:

1. Tipton KD. Nutritional Support for Exercise-Induced Injuries. Sports Med. 2015;45 Suppl 1:S93-104.
2. McInnis, Katie, PHD, RD, LD. Sports Nutrition for the Injured Athlete. 2020 SCAN Sports Nutrition Webinar.
3. Lin E, Kotani JG, Lowry SF. Nutritional modulation of immunity and the inflammatory response. Nutrition. 1998;14(6):545-50.