Abstract
ecreational runners are prone to injury, leading to decreased levels of physical activity and well-being. Fortunately, injury prevention methods reduce risk and can benefit athletic performance. By synthesizing current literature, this paper details how nutrition, sleep, stretching, and thermotherapy can improve muscular recovery to avoid injury. Fat, protein, carbohydrate, caffeine, water, and electrolyte consumption should be moderated by general guidelines and personalized based on energy expenditure. While disturbed sleep patterns have minimized effects on running performance, runners should avoid sleep deprivation due to its detrimental impact on muscular recovery and mental health. Consistent and well-validated recovery techniques should be used, such as applying cold therapies immediately post-exercise and heat therapies later in the recovery process. For warmups, prioritizing dynamic stretching over static, ballistic, or PNF stretching is also recommended to protect the runner from muscular strain by maintaining a healthy range of motion across joints. By incorporating strategies from each category into a comprehensive recovery routine, intermediate and novice runners can protect and prolong their ability to be physically fit. KEYWORDS: Health Sciences, Sports Medicine, Running, Recovery, Preventing injury. � Introduction Almost half of all intermediate runners get injured every year.¹,² This unfortunate reality can make running highly dis- heartening to many athletes. To add on, running supersedes the rate of self-injury in every other sport except basketball.³ Why, then, is running still the most popular sport in the world? Because it’s easy? Definitely not. Logically, the reason could be because it’s the most accessible - you can run anywhere. But also, to cite Christopher McDougall from his novel, Born to Run, “Running was the superpower that made us human.”⁴ Running is naturally developed, whereas sports like football, basketball, and cricket are all human creations. As everyday life has become more sedentary - even more so with the COVID-19 quarantine- some individuals have be- come physically incapable of carrying out people’s daily tasks from just 200
from his novel, Born to Run, “Running was the superpower that made us human.”⁴ Running is naturally developed, whereas sports like football, basketball, and cricket are all human creations. As everyday life has become more sedentary - even more so with the COVID-19 quarantine- some individuals have be- come physically incapable of carrying out people’s daily tasks from just 200 years ago. In the last 20 years alone, obesity prevalence increased by 10% among Americans.⁵ This may be because of the rise in consumption of fatty foods, which run- ning can help counter.⁶ Running also improves cardiovascular health, reducing death risks and prolonging life.⁷ Research on the benefits of running states, “Runners have found a new and interesting medium for renewed interest in their bod- ies as vehicles for reaching some standards of physical and self-accomplishment which they were unaware of.”⁸ When intermediate runners are injured, they are often discouraged and may lose interest in running, causing them to lose valuable benefits. In a way, running is almost necessary for all human beings - a perpetually prescribed medicine. Many runners experience immense frustration due to injuries. Since some injuries can be quite debilitating, it is im- perative to keep the body healthy. The purpose of this paper is to discuss ways in which intermediate runners can avoid injury. While most of this information applies to athletes of all lev- els, the general overview provided is more suitable for newer runners (at the high school and recreational levels). Hence, the paper focuses on ‘intermediate’ runners. Nutrition: A runner’s nutrition can impact their perception of a race or training session and be the difference between an excruci- ating five miles and a blissful five miles. To avoid injury and sustain high performance, it is imperative to ingest the right kind of nutrients and meet the energy intake requirements.⁸,⁹ Unfortunately, no one diet plan fits all athletes as individual differences in metabolic rates, allergies, and other factors influ- ence food selection and consumption. One important theme is that moderation and balance must be used in the diet to allow for optimal recovery and
it is imperative to ingest the right kind of nutrients and meet the energy intake requirements.⁸,⁹ Unfortunately, no one diet plan fits all athletes as individual differences in metabolic rates, allergies, and other factors influ- ence food selection and consumption. One important theme is that moderation and balance must be used in the diet to allow for optimal recovery and performance. The following infor- mation will provide general nutritional recommendations and information specific to runners. Fats, proteins, and carbohydrates are the three categories of substances that fuel the engine that is our body.¹⁰ The energy created from these nutritional compounds travels in the form of a molecule known as adenosine triphosphate (ATP).¹¹ All three substances are essential and must be kept in a healthy ratio to allow the numerous body systems to function at top condition during workouts, runs, or races. The information above contrasts with the common mis- conception that fats must be avoided. It is recommended that endurance athletes (who participate in >2hr endurance exer- cises daily) ingest 2 grams of fat per every kg of body weight daily because it is a significant energy provider.¹² Too much fat could adversely impact performance by consuming fewer car- bohydrates and proteins. A lack of fat (primarily found when runners attempt to lose weight) can deplete runners’ energy REVIEW ARTICLE ijhighschoolresearch.org
121 and hinder performance.¹² Moreover, injury rates increase when an endurance athlete consumes less fat or when a smaller percentage of energy intake is from fats.¹³ This reinforces the importance of a healthy amount of fat in every diet. One study found that, regardless of other total energy intake, a lower fat diet often resulted in increased stress fractures, demonstrating that a fat deficit could weaken bones.¹⁴ All in all, it is essen- tial to maintain a diet with a relatively balanced amount of fat intake. Proteins, another energy source, are arguably the most im- portant in an athlete’s diet. Proteins comprise thousands of amino acids and provide essential structural and regulatory benefits to muscles.¹⁵ As all amino acids contain nitrogen, scientists can calculate the daily recommended protein intake by attempting to balance out the nitrogen intake and output (urine, sweat, etc.). Since that output increases with physical activity, endurance athletes require more protein intake.¹⁶ The average daily requirement for a regular person (non-athlete) is estimated to be 0.8 gram/kg body weight/day, whereas an en- durance athlete requires of recovery 1.2g-1.4g/kg body weight/ day.¹⁶ To increase the efficiency and the amount of muscle re- placed, protein is the most important nutritional component because proteins provide the amino acids to repair, resize, and build the new muscle tissue.¹⁷ To perform at our best level and prevent injury, it is imperative that the muscle tissue is allowed to heal, and proteins allow for that, fortifying the necessity of protein in our diets.¹⁸ Protein can be found in plant-based foods (nuts, soy, beans, lentils, peas) and animal-based food (eggs, meat, and fish).¹⁹ To conclude, protein is essential for runners because of its increased use with endurance exercises and immense benefits on recovery. During endurance exercise, out of the three energy sourc- es, carbohydrates are the most essential.²⁰ At the most basic level, our body converts carbohydrates into glucose to create energy for our muscles to operate and stores the remnants as glycogen or fat to use later.²¹ Therefore, glucose is essential to the diet because it facilitates movement. Popular foods with a high
endurance exercise, out of the three energy sourc- es, carbohydrates are the most essential.²⁰ At the most basic level, our body converts carbohydrates into glucose to create energy for our muscles to operate and stores the remnants as glycogen or fat to use later.²¹ Therefore, glucose is essential to the diet because it facilitates movement. Popular foods with a high concentration of carbohydrates include potatoes, bread, and various grains (rice, cereal).²² For endurance athletes, it is recommended to consume about 500g of carbohydrates daily,²³ though the average American adult intake is said to be 287g.²⁴ Ingesting carbohydrates post-exercise benefits the glycogen levels in your muscles and allows for more energy to ensure recovery.²⁵,²⁶ While carbohydrates are essential, spe- cific sub-types may be detrimental in excess. For instance, as sugar consumption has significantly increased over the past few decades, consumption recommendations have become a highly debated topic.²⁷ Generally, ingesting carbohydrates does not negatively impact runners, mainly because they can be effectively used as monosaccharides or glucose/glyco- gen.²⁸ However, when a specific subsection of carbohydrates, disaccharides, is ingested in excess, it can lead to increased inflammation.²⁹ Therefore, athletes should be cautious of the types of carbohydrates they ingest. As caffeine intake becomes increasingly prominent, primar- ily through the large variety of American drinks, top research institutions suggest that individuals should consume less than 400 milligrams of caffeine daily.³⁰,³¹ However, these recom- mendations may not apply to athletes as caffeine suppresses natural signals from neurotransmitters for rest, recovery, and sleep.³²,³³ If caffeine is ingested when the body is tired and ask- ing for rest, the body is forced to push through fatigue. Caffeine can also increase urination excretion, leading to dehydration and a loss of various nutrients that could adversely impact re- covery.³⁴ Each of these nutrients (e.i., Calcium, Vitamin D, and Iron) have its own pertinent purposes, and any inadequacy could adversely impact the body, especially when being taxed by running.³⁵,³⁶ Hints that caffeine negatively impacts cardio- vascular health, most specifically through increasing the risk of coronary heart disease, suggest that decreased quantities may protect against chronic health issues.³⁷,³⁸ However, when consumed
Each of these nutrients (e.i., Calcium, Vitamin D, and Iron) have its own pertinent purposes, and any inadequacy could adversely impact the body, especially when being taxed by running.³⁵,³⁶ Hints that caffeine negatively impacts cardio- vascular health, most specifically through increasing the risk of coronary heart disease, suggest that decreased quantities may protect against chronic health issues.³⁷,³⁸ However, when consumed in moderation, caffeine’s stimulating properties may improve performance and preserve muscle glycogen.³⁹ To con- clude, caffeine may enhance race performance but is generally detrimental during training. Regularly drinking water, or hydrating, is crucial to a run- ner’s nutrition. Dehydration consistently reduces aerobic capacity in runners,⁴⁰ predominantly due to the increase in body temperature, which induces a more incredible feeling of fatigue.⁴¹ Furthermore, evidence also indicated dehydration and hyperthermia (raised body temps) could cause extra car- dio-vascular strain during exercise.⁴² In most endurance races, the cardio-vascular system demands a lot, as it usually has to be pumping blood at a fast pace for hours, demonstrating how important it is to avoid any strain.⁴² Dehydration also restricts exercise heat acclimation, or how the body can get used to running in the heat, which limits the body’s capabilities.⁴³ Ad- ditionally, the body needs extra hydration to stay cool in the heat. To compete at a runner’s optimal level, the athlete must hydrate to avoid excess fatigue, cardio-vascular strain, and heat acclimation loss. When going on long runs, water lost in sweat loss may exceed the amount of water intake. If attempts at rehydration are not used at this point, similar symptoms of dehydration can ensue.⁴⁴,⁴⁵ Moreover, dehydration does not only occur with exercise. When people wake up in the morn- ing, they have most likely been fasting (not eating or drinking) for the past 10 hours. It is essential to combat this complete dehydration by drinking a surplus of water to allow for various benefits.⁴⁶ To combat increased body heat during exercise, the body releases sweat, which results in not only a loss of water but also electrolytes.⁴⁷ Electrolytes, such as sodium, potassium, and chloride, are all crucial parts of basic body functionality
past 10 hours. It is essential to combat this complete dehydration by drinking a surplus of water to allow for various benefits.⁴⁶ To combat increased body heat during exercise, the body releases sweat, which results in not only a loss of water but also electrolytes.⁴⁷ Electrolytes, such as sodium, potassium, and chloride, are all crucial parts of basic body functionality and are ingested through various foods and drinks.⁴⁸ Major sodium deficits are correlated with performance decreases and health hazards.⁴⁹ This emphasizes the importance of maintaining a healthy electrolyte level pre-exercise and throughout everyday life. In addition, electrolytes should also be consumed to allow for the desired recovery, especially leading up to powerful per- formances.⁵⁰ Unfortunately, no set number of electrolytes is required for every runner - it varies from person to person. To reduce electrolyte loss and increase sweat efficiency, runners can use the body’s acclimation ability by getting used to the heat and climate.⁵¹ Keeping the body’s electrolyte levels healt- DOI: 10.36838/v5i5.22 ijhighschoolresearch.org
122 tension following training. By elongating muscles, stretching increases flexibility and mobility while alleviating tension.⁶²,⁶³ Unfortunately, stretching for a singular time, like most re- covery techniques, is a temporary relief and does not provide long-term benefits.⁶⁴ This means runners must stretch con- sistently to get full mobility and flexibility benefits. There are four categories of stretches, all of which have their purposes.⁶⁵ The first category of stretches, and the most common ones, are known as static stretching. Static stretching involves extending a limb to its full range of motion and hold- ing that dormant state for 15-60s.⁶⁶ While static stretching increases flexibility, it does not consistently improve running economy or distance performance making it an effective technique only in the short term.⁶⁷ As one would imagine, there are countless static stretches, and it is essential to make a solid routine of stretches to complete throughout the day. One study found static stretching, specifically a supine leg lift, to increase the elasticity of the hamstring, which in turn, in- creased the flexibility. In muscular studies evaluating runner performance, hamstrings are found to take the brunt of the force when shifting weight from leg to leg between strides, which demonstrates that it is imperative to keep the ham- strings in top shape.⁶⁸ Dynamic stretching, the lengthening of a muscle in motion, contributes to flexibility and dynamic balance im- provements.⁶⁹ Just as flexibility is critical in preventing injury, dynamic balance helps avoid musculoskeletal injuries like an- kle sprains.⁷⁰ Dynamic stretching also tends to be orientated towards a specific sport because different types of balance are needed for different sports. In running, you need to control your motion perfectly with each stride, which comes with dy- namic exercises for your legs. For instance, leg lifts, commonly referred to as Frankenstein kicks, involve balancing on one leg while extending the other in its full range of motion. The third category of stretches is ballistic stretching, a swifter type of stretch that involves a body part stretching to its limits with momentum or gravity.⁷¹,⁷² Completed very quickly, ballistic stretching makes it challenging to control the intensity
lifts, commonly referred to as Frankenstein kicks, involve balancing on one leg while extending the other in its full range of motion. The third category of stretches is ballistic stretching, a swifter type of stretch that involves a body part stretching to its limits with momentum or gravity.⁷¹,⁷² Completed very quickly, ballistic stretching makes it challenging to control the intensity of the movement and may pose an injury risk.⁷³ In comparison, ballistic stretching is more like a pulse of a stretch, while dynamics are slower and more orientated to- ward the range of motion practiced in the exercise. The last stretching category includes proprioceptive neuro- muscular facilitation (PNF) stretches. PNF stretches improve muscle elasticity by using a pattern of contracting and re- laxing agonist and antagonist muscles, improving flexibility and range of motion.⁷⁴,⁷⁵ Agonist and antagonist muscles are inverse or opposite muscles (i.e., hamstrings/quads, biceps/ triceps). So, PNF stretching involves activating a muscle to influence a passive stretch of the opposite muscle.⁷⁶ These stretches are less common because they typically require an outside trainer or extra exercise tools. Scientists have conducted many studies exploring effective ways to incorporate these four types of stretches into muscu- lar warmups. Warming up before exercise prepares the body for movement by raising the internal muscle temperature by 1 or 2 degrees Celsius and stimulating all body parts required hy is almost as crucial to health, performance, and recovery as hydrating. Sleep: Historically, humans have had to sleep 6+ hours daily to survive.⁵² Today, people often disregard that fact and use the night to complete the immoderate amount of work thrown at them. For instance, according to the CDC, 71% of high schoolers sleep less than the recommended 8 hours.⁵³ While some people can survive without much sleep, an athlete, who pushes their body in ways others do not, requires a substantial amount of bedtime.⁵⁴, ⁵⁵ Athletes need enough sleep to relieve the body from physically demanding training. When com- mitted to a rigorous training plan, runners often have lower sleep efficiency and longer sleep latency.⁵⁵ In other words, due to the significant impact running
without much sleep, an athlete, who pushes their body in ways others do not, requires a substantial amount of bedtime.⁵⁴, ⁵⁵ Athletes need enough sleep to relieve the body from physically demanding training. When com- mitted to a rigorous training plan, runners often have lower sleep efficiency and longer sleep latency.⁵⁵ In other words, due to the significant impact running has on your body, it takes longer to get to bed, and you get less out of time in bed. This suggests that runners need more time in bed to get the same amount of sleep as non-runners. Sleep loss can hinder the assembly of muscle protein, which impedes the recovery process.⁵⁶ When the muscles cannot heal themselves, damage accumulates and often leads to injury. So, patterns of sleep loss must be addressed to avoid negative impacts on training. Many 5k racers find that the night before their race yields barely 6 hours of sleep, but they can still perform at their top level the next day.⁵⁷ Most studies categorize 24 hours or one full day without sleep as deprivation. Anything less than deprivation seems to have little to no effect on a runner’s race-day performance. In contrast, sleep deprivation has a significant effect.⁵⁸ To clarify, a minor loss of sleep (2-4 hours under regular sleep time) will not impact your endurance performance in a one-time occurrence, disregarding psycho- logical reasons. Five scientists and professors from the UK found that the cardio-respiratory and thermoregulatory functions during endurance training displayed minimal fluctuations between sleep deprivation and regular sleep.⁵⁹ However, the sleep-de- prived athletes covered less distance.⁵⁹ This indicates the fascinating possibility that sleep deprivation affects a runner’s perceived effort. In other words, the runners felt like they were doing the same work but ended up running a short- er distance. This mental effect is detrimental to any runner’s performance. In addition, Skein and colleagues found that 30 hours of sleep deprivation resulted in muscle glycogen loss.⁶⁰ Muscle glycogen is a glucose polymer that surrounds mus- cles and provides muscles with a way to produce ATP. When there is a reduction in
work but ended up running a short- er distance. This mental effect is detrimental to any runner’s performance. In addition, Skein and colleagues found that 30 hours of sleep deprivation resulted in muscle glycogen loss.⁶⁰ Muscle glycogen is a glucose polymer that surrounds mus- cles and provides muscles with a way to produce ATP. When there is a reduction in the glucose polymer, there is also a reduction in the rate of production of ATP.⁶¹ So, sleep depri- vation actually reduces the body’s capacity to do work, which is disastrous to any runner, especially on race day. Therefore, while sleep is crucial for a runner’s success, it is the hardest for us to attain, and sleep deprivation, a total of 24 hours without sleep, can be lethal for performance through mental or physical issues. Stretching: Runners often rely on stretching, a “movement applied by an external and internal force to increase muscle flexibility and joint range of motion”,⁶² to relieve muscle stiffness and DOI: 10.36838/v5i5.22ijhighschoolresearch.org
123 for running.⁷⁷,⁷⁸ Researchers recommend active warmups, which refer to stretching and movement, rather than passive warmups, which usually involve hot showers or saunas. How- ever, exerting too much effort during warmups can hinder short-term performance.⁷⁹ For many years, scientists have recommended that active warmups include static stretching, but new evidence indicates that static stretching in warmups exhibits almost no difference when compared to no warmup.⁸⁰ Further studies report that static stretching may lead to ad- verse effects. A study conducted with experienced collegiate male runners demonstrated how static stretching lowered the distance covered in a 30-min run because it increased the en- ergy required to run.⁸¹ Since this shift in general consensus occurred in the last decade, it is important to note that sud- denly eliminating static stretching from a seasoned runner’s routine could lead to a negative psychological response.⁸² In contrast, warming up with dynamic stretching benefits performance. Seasoned coaches worldwide almost always in- corporate dynamic stretching into their athlete’s pre-exercise routines. Often, dynamics involve approximately 20 yards of each stretch, with about three steps in between each rep. While static stretching’s impact on neural activation is lim- ited, dynamic stretching more effectively primes the body for movement by integrating patterns of motor neuron activation that occur during running into the warmup process.⁸³ For instance, dynamic stretches improve the height of a two-leg jump in women, whereas static stretching decreases that per- formance. Since leg muscles are as crucial in running as in jumping, dynamic stretching appears effective for a warmup. Ballistic stretching is not as favorable as a warmup stretch be- cause of its potential to injure and has been proven ineffective in many studies. One study determined that ballistic stretch- ing had a similar effect to not stretching in a warmup.⁸⁴,⁸⁵ Lastly, PNF stretching is found to decrease muscular perfor- mance as a part of warmup before exercise.⁸⁶ In conclusion, modern consensus suggests that dynamic stretching is the most fruitful method of warming up and can benefit runners in ways other forms of stretching cannot. As for the other stretches, they are generally better for post-exercise