We have been getting a lot of questions on nutrition for injuries recently. We reached out to medical colleagues for answers. Andrew Dole who is a Registered Dietician specializing in Performance Nutrition agreed to write an in-depth post for us. Below is the start of multiple blog posts on this topic. If you have additional questions, Andrew has been kind enough agree to answer questions through his website www.bodyfuelspn.com .
Nutrition for Soft Tissue Injury Recovery, Part I Protein
Andrew Dole, RDN
Body Fuel Sports Performance & Lifestyle Nutrition
Impact of Injury on Muscle
Not being able to move an injured muscle or joint can be expected following a sport related accident or planned procedure. This disuse causes the loss of muscle tissue and strength in the affected area. The amount of rehabilitation required is influenced by the amount of muscle lost during the immobilized recovery period. An emphasis on proper nutrition during this initial phase and the following recovery phase may lessen the muscle wasting effect of injury and improve recovery outcomes.
A muscle that can’t move, because of injury, undergoes metabolic changes. One of these changes is called anabolic resistance. Eating protein stimulates the making of muscle tissue for repair or new muscle building. In a healthy moving muscle this process works normally and muscle tissue responds to protein intake. The immobilized or injured muscle in anabolic resistance does not respond to the same amount of protein intake and cannot repair or make new muscle tissue as effectively.
Minimizing Muscle Loss
Therefore, maximizing the protein building response at each meal is a useful strategy for lessening, but not preventing, the inevitable muscle wasting that occurs in an injured muscle.
Simply increasing protein intake throughout the day or over consuming protein at meals would not be ideal. While protein intake does stimulate muscle synthesis there is a limit to how much the body can be achieve.
Protein at Meals
A great deal of research around the minimum quantity of protein needed stimulate muscle building has been done; 20 g of protein in young men and 34-40 g in those >65 years of age. So eating more protein won’t improve muscle synthesis, but it does help provide the necessary building blocks (nitrogen balance) required to support whole body muscle recovery and repair.
This increased rate of synthesis lasts for up to 5 hours after eating and peaks at 2-3 hours. Spreading out the maximal protein intake evenly throughout the day takes advantage of this increased muscle building window more frequently.
For example – eating 4-6 meals with the minimum required protein would provide 8-12hrs of time spent in the maximal anabolic window. In contrast, eating 3 meals or a low protein breakfast provides 4-6hrs and would not take advantage of the whole day.
Daily Protein Needs
Again, not looking at the whole picture is ineffective. Eating 20g of protein 4-6 times a day may not provide enough total protein to support the whole body for some individuals. Estimating total daily protein needs is necessary.
An increased protein intake for soft tissue recovery is based upon research that shows 1g/kg of protein is enough to prevent the decline of muscle synthesis. However, in an injured stated two things need to occur. First, we need to overcome anabolic resistance. Second, we need to support the body’s additional protein needs for injury recovery. Therefore, a goal of 1.2 -1.6g/kg of protein would provide adequate protein intake to support soft tissue recovery.
The protein needs of a well-trained or competitive athlete will be higher. 1.8-2.0 g/kg could be required as evidence shows 1.6g/kg of protein merely maintains nitrogen balance.
I Can’t Eat Math
Translating this to food for a 170# moderately active, 35 yo male would look like this:
170# converted to kg (170# / 2.2) is 77 kg
77kg x 1.5 g/kg protein = 116g protein daily
116g protein / 5 meals = 23g protein per meal from all sources; whole food plant and animal or supplemented.
On the plate: 2-3 ounces of meat, ½ cup whole grain, 1 oz nuts, and lots of fruits and vegetables.
Wasn’t 20g All I Needed
To stimulate the body to make the most new muscle tissue, yes. But each individual has different needs. To support the rebuilding of all the muscles in the body more daily protein may be needed to provide the building blocks for tissue building.
Balancing Inactivity and Intake
Balancing total calorie consumption with optimal protein intake when injured can be problematic. Injury most often translates into inactivity and the need for fewer total calories. However, a reduction in overall calories will result in a decrease of protein as a relative percentage of intake. This cut in daily protein can fail to meet the required intake for muscle maintenance and repair of the injured area.
In fact, an energy deficit or under eating to prevent fat gain is counter-productive. In addition to reducing protein, calorie deficits are known to impede recovery and exacerbate the inflammation process.
In part two we will discuss how to balance calorie needs for soft tissue injury repair and inactivity.
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Tipton KD. Nutrition for acute exercise-induced injuries. Ann Nutr Metab. 2010;57 Suppl 2:43-53.
Mahan LK, Escott-Stump S. Krause's Food & Nutrition Therapy. Saunders; 2008.