In Search of the Runner’s High
(But at what cost??)
By
Jason Shea PICP Level III, MS, CSCS
Excessive (ĭk-sěs'ĭv): exceeding what is proper, necessary, or normal; going beyond the usual, necessary, or proper limit or degree
Each and every morning thousands of health conscious adults can be seen pounding the pavement one foot-strike at a time in search of optimal health, weight loss, and stress reduction. Sadly though, many of those foot-strikes (roughly 1760- 2640 foot-strikes per mile (5280 feet per mile/2-3 feet per stride average)) take place on excessively over-pronated ankles, weak VMO musculature exhibiting valgus stress (knock kneed), and hip tilts leading to structural imbalances through the pelvis and spine. Over time, the combination of cumulative trauma from thousands of foot-strikes utilizing improper biomechanics and an imbalanced hormonal profile can lead to many unwanted side effects including weight gain, adrenal fatigue, chronic pains, and increased potential for acute traumas.
Is high volume endurance training as beneficial to human health as its proponents claim. In healthy individuals appropriate levels of endurance training has been shown to have positive benefits on cardiovascular health, emotional health, and body composition. But in individuals with less than optimal health, could the positive benefits be negated, leading to a chronic state of catabolism and breakdown. Was the human body designed for excessive levels of endurance training? Looking back on Paleolithic history, did prehistoric man need to chase food over excessively long distances at a 6 minute mile pace, or did they use their brains to set traps and create weapons, then sprint after their prey once it was injured. Looking at the healthy, well muscled, lean physiques of Olympic sprinters compared to that of a competitive marathon runner or excessively trained triathlete , one may jump to the conclusion that our bodies may not have been designed for the traumas of excessive endurance training.
It basically comes down to a question of individuality. Is your health optimal (injury/inflammation free, disease free, hormonally balanced, optimal cardiovascular health, and healthy body composition) and why do you run (or any other form of long slow distance training)? If for competitive purposes, by all means, keep pursuing your competitive goals (injuries withstanding). But, if weight loss, emotional health, and “to keep in shape” are the primary reasons, a reevaluation of the scientific literature may provide insight as to why some of the leanest, happiest, healthiest, and least injured athletes/fitness enthusiasts take a minimalist approach with regards to endurance training. Perhaps a deeper look into the science may allow endurance training enthusiasts some positive rationale as to why they can drop the Advil bottle and hold off the treadmill for a day…. or two, and allow those aches and pains to finally heal, without gaining weight.
Endurance Training and Weight Gain
In some individuals can excessive endurance training lead to weight and body fat gain? Below are some real world testimonials from high volume endurance training athletes.
“Since IMA last summer, I've been ultrarunning, and have my first 100K coming up in two weeks. But I'm the heaviest I've been in five years! I've actually gained 5 pounds, and it doesn't seem to be lean muscle. My scale reports a body fat of 23%”
“I am getting really upset that I've actually gained weight running 30-50 miles weekly. This is my first time training for a marathon. Prior to this, I always ran 15-20 miles a week, cycling, pilates classes, weights, etc. Since the training started I've had less time for other forms of exercise. I've put on almost 10 lbs in 4 months. it's not all muscle b/c my clothes are tighter.”
“I too have gained about 7-10 pounds from upping mileage. I've actually had to decrease my calories to lose some of the weight. Do you think you're snacking more often than you should?”
“I too have gained about 5-7 pounds while training for the marathon this summer. I know for me, that it is due to more calories in than out, but it sure doesn't feel like it at the time.”
“Wish I had good news for ya'--I don't---the more miles I run, the fatter I get.”
“I am currently training for my 4th marathon, and I always gain 5 to 10 pounds of weight as well before each marathon. Although I do lose the weight again after the marathon, I dislike the feeling of that extra weight on me, and always wondered what the cause was. I did cut out a lot of my cross-training activities and replaced them for training runs which I thought might be the culprit, because as far as caloric intake, I've kept a daily diary for years, and I had not been consuming enough extra calories to account for all of the pre-marathon weight gain.”
“I'm currently doing about 75 mpw. I have also noticed that tendency to gain weight during marathon training. I've found that since I upped my mileage in July, I've had to really watch the calories to keep from adding pounds”
“My experience was very similar to some of those above in that I gained about 10 lbs. during training this summer. I didn't lose any right after the race either.”
"I'm training for a marathon and I'm gaining weight!" Surprisingly, this complaint is actually somewhat common. Often, people start marathon training with the expectation that the pounds will just start falling off them. But some are shocked when they see that number on scale start to creep up.”
These are just some of the examples of postings on endurance training forums found across the internet. Sadly, though the information many of these athletes are given regarding this excessive weight gain revolves around increased caloric consumption or lack of training mileage (see replies to posting below). When in actuality it may be much more complicated than running more and eating less, as there no lack of scientifically based evidence and literature as to why these athletes might be gaining weight. An understanding of the endocrine system and how one’s hormonal profile is regulated can be a good starting point for solving this “mystery” weight gain amongst excessively trained endurance athletes.
“The way your body is now is due to the things you have been doing over the last 12 months. So if you feel flabby; then either cut back on the calorie intake or increase exercise or both. If I want to lean down; I skip dinner and use a meal replacement.”
“I'm laughing at myself as I sit here at work and look at my desk...there's a baggie of pretzels (salt for my midnight run tonight!), a banana, a couscous/chickpea/date/pine nut/carrot salad, an apple, some carrots and a big bottle of water. I also snagged some whole-grain bagels (to take home) that someone brought in from the Fresh Market. And I'm considering those animal crackers in the vending machine too.”
Enter Cortisol
According to Dr. Shawn Talbott, “stress makes a person fat primarily because of an excessive secretion of the key stress hormone, cortisol, along with a reduced secretion of key anabolic hormones, such as DHEA and Growth Hormone. The combination of high cortisol and low DHEA causes the body to store fat, lose muscle, slow metabolic rate, and increase appetite—all of which have the ultimate effect of making a person fatter (28).” “During periods of chronic stress, levels of both cortisol and insulin rise and together send a potent signal to fat cells to store as much fat a possible. They also signal fat cells to hold on to their fat stores—so stress can actually reduce the ability of the body to release fat from its fat stores to use for energy (28).”
What exactly does cortisol do? “One of cortisol’s many functions is that it stimulates the release of glucose, fats, and amino acids for energy production. In the liver, cortisol stimulates the breakdown of glycogen into glucose. In the adipose tissue, fatty acids are released in response to cortisol stimulation (fat breakdown?—sounds good—but the longer-term effect is fat gain). In the skeletal muscles, cortisol promotes the release of amino acids, which are either used directly by the muscle for energy or sent to the liver for conversion into glucose. The main problem with this last scenario, however, is that if it continues for any prolonged period of time, a significant amount of muscle mass may be lost (bad news for long-term weight maintenance) (28).”
“Scientific research and medical evidence clearly show that a sustained high level of cortisol, coming from chronic, unrelenting stress, has a debilitating effect on long term health. Among these many effects is an increase in appetite and cravings for certain foods. Because one of the primary roles of cortisol is to encourage the body to refuel itself after responding to a stressor, an elevated cortisol level keeps your appetite ramped up—so that you feel hungry almost all the time. In addition, the type of fat that accumulates as a result of this stress induced appetite will typically locate itself in the abdominal region of the body (probably so it is readily available for the next stress response). The major problem with abdominal fat, aside from the fact that nobody wants a pot belly, is that this type of fat is also highly associated with the development of heart disease, diabetes, and cancer (28).”
“Researchers at the University of Colorado have conducted several studies showing how exercise can reduce many of the detrimental effects of chronic stress. The Colorado researchers have also shown that extremes of exercise, such as that undertaken by over trained endurance athletes, can reverse these benefits by elevating cortisol levels, increasing body fat, interfering with mental and emotional functioning, suppressing immune functioning, and increasing the risk of injury (28).”
Additional Research Studies on Cortisol and Body Fat Storage
· Rosmond R, Björntorp P. Quality of life, overweight, and body fat distribution in middle-aged men. Behav Med. 2000 Summer;26(2):90-4.
“Impaired quality of life may be causally related to the development of abdominal obesity; the mechanism involved might be increased cortisol secretion, which can redistribute body fat to central adipose tissue depots.”
· Lottenberg SA, Giannella-Neto D, Derendorf H, Rocha M, Bosco A, Carvalho SV, Moretti AE, Lerário AC, Wajchenberg BL. Effect of fat distribution on the pharmacokinetics of cortisol in obesity. Intl J Clin Pharmacol Ther. 36(9); Pp 501-505. 1998
“Patients with larger intraabdominal fat areas were found to have a higher cortisol clearance than those with lower intraabdominal fat areas. Cortisol clearance (both, absolute and body-weight corrected) showed a statistically significant correlation with intraabdominal fat area, either expressed by waist-hip ratio or obtained by computerized tomography. CONCLUSIONS: These findings indicate a more effective clearance capability for cortisol in patients with central obesity resulting in lowered cortisol plasma levels despite an increased cortisol secretion observed in this patient group.”
· Andrew R, Phillips DI, Walker BR. Obesity and gender influence cortisol secretion and metabolism in man. J Clin Endocrinol Metab. 1998 May;83(5):1806-9.
· Balestreri R, Jacopino GE, Foppiani E, Elicio N. Aspects of cortisol metabolism in obesity Arch Maragliano Patol Clin. 1968 Jul-Aug;24(4):431-41
· Björntorp P, Rosmond R. Obesity and cortisol. Nutrition. 2000 Oct;16(10):924-36.
· Rosmond R, Dallman MF, Björntorp P. Stress related cortisol secretion in men; relationships with abdominal obesity and endocrine metabolic and hemodynamic abnormalities. J Clin Endorcrinol Metab. 83(6); Pp 1853-1859. 1998.
Disruption of hormonal balance through excessive endurance training can also lead to high levels of oxidative stress, burned out adrenal glands, and deficiencies in vital minerals. “When a person is in a state of stress, the hormones secreted by the adrenal glands suppress the immune response (25).” This decreased immune response can be a symptom or cause of excessive Oxidative Stress: “a physiological condition in which increased concentration of reactive oxygen species (ROS) is not properly counterbalanced by increased presence of oxygen metabolite-processing enzymes and free radical quenching molecules (12). “
Though often overlooked, mineral deficiencies can also play a key role in one’s decreased immune response. According to Dr. Carolyn Dean, “heavy exercisers, especially long-distance runners, can build up lactic acid and suffer shin splints and painful muscles, but they keep on running because they may be addicted to the adrenaline rush they get when they reach “the wall” in their workout. The wall feels like something you just can’t breakthrough, but you keep on pushing, and suddenly you get a burst of adrenaline and you’re flying. That’s the power of your adrenal glands when pushed to the maximum. Yet that stress induced high is followed by a crash when you don’t repair the damage to your adrenal glands with good nutrition (6).”
“Many studies have shown that magnesium supplementation enhances the performance and endurance of long distance runners, cross-country skiers, cyclists, and swimmers. It also reduces lactic acid buildup and post-exercise cramps and pain. Since athletes undergo severe physical stress as well as the psychological drive to win, and most ingest suboptimal amounts of magnesium, they are vulnerable to magnesium deficiency (6).”
In simplified terms:
Excessive Endurance Training = Increased Potential for Elevated Cortisol + Increased Potential for Overworked Adrenal Glands + Increased Potential for Mineral Deficiency = Increased Potential for Weight/Body fat Gain.
Endurance Training and Testosterone Levels
Inside the human body is a constant balancing act between the major and minor hormones, each doing their part to regulate the body’s systems and maintain homeostasis. If this balance is disrupted, a shift in one’s internal hormonal profile can occur. For instance, an increase in cortisol and insulin can lead to a decrease in the rebuilding hormone, Testosterone. If an athlete or fitness enthusiast’s testosterone drops due to excessive endurance training, the athlete may be susceptible to many of the previously discussed negative health effects. So, does endurance training lower one’s testosterone? A brief look at just a small sampling of the scientific literature may provide some insight.
1. Maïmoun L, Lumbroso S, Manetta J, Paris F, Leroux JL, Sultan C. Testosterone is significantly reduced in endurance athletes without impact on bone mineral density. Horm Research. 59(6); Pp 285-292. 2003.
“TT (total serum testosterone) and FAI (free androgen index) levels were lower (p < 0.05) in CY (cyclists) and TR (triathletes)”. “Only the endurance training of CY (cyclists) and TR (triathletes) induced androgen deficiency without apparent alteration of BMD”
2. Smith R, Rutherford O. Spine and total body bone mineral density and serum testosterone level in male athletes. European Journal of Applied Physiology and Occupational Physiology. 67(4); Pp 330-334. 1993
“Serum testosterone levels were significantly lower in the triathletes than in the controls (P < 0.05).” “The heavy weight training typical of rowing training seemed to result in significant bone accretion. The low testosterone levels in the triathletes may have negated any positive effect of the increased exercise on BMD.”
3. Wheeler G, Singh M, Pierce W, Epling W, Cumming D. Endurance training decreases serum testosterone levels in men without change in lutenizing hormone pulsatile release. Journal of Clinical Endocrinology and Metabolism. 72(J2); Pp 422-425. 1991
“Over 6 months of training, the men increased weekly running mileage to an average of 56 km/week. Total testosterone and free androgen index levels decreased significantly. These data confirm previous findings of physiological reduction in serum
testosterone and PRL levels and suggest that the testosterone decrease is not related to changes in LH pulsatile release, weight, or increased serum cortisol levels.”
4. Urhausen A, Kindermann W. Behavior of testosterone, sex hormone binding globulin (SHBG), and cortisol before and after a triathlon competition. International Journal of Sports Medicine. 8(5); Pp 305-308. 1987
“The data suggest an anabolic deficit lasting for several days as a result of prolonged physical strain.”
5. Izquierdo M, Ibanez J, Hakkinen K, Kraemer W, Ruesta M, Gorostiaga E. Maximal strength and power, muscle mass, endurance and serum hormones in weightlifters and road cyclists. Journal of Sports Sciences. 22(5); Pp 465-478. 2004.
“Basal serum total testosterone and free testosterone concentrations were lower in elite amateur cyclists than in age-matched weightlifters or untrained individuals. The results suggest that, in cycling, long-term endurance training may interfere more with the development of muscle power than with the development of maximal strength, probably mediated by long-term cycling-related impairment in anabolic hormonal status.”
6. Hackney A, Fahrner C, Gulledge T. Basal reproductive hormonal profiles are altered in endurance trained men. Journal of Sports Medicine and Physical Fitness. 38(2); Pp 138-141. 1998.
“Results indicated that the basal T and fT of the ET men were significantly (p < 0.01) lower than that of the SED men. The levels of these hormones in the ET men where in the normal clinical range, but represented only 55% to 85% of those seen in the SED men. ET men have lowered basal T and fT levels and this suppression may be related to an alteration in the hypothalamic-pituitary-testicular regulatory axis since the LH of the ET was not elevated. Whether these hormonal changes have any significant beneficial (i.e., protective cardiovascular) or negative (i.e., decrease anabolic-androgenic processes) physiologic consequences remains to be determined.”
7. Hackney A, Szczepanowska E, viru A. Basal testicular testosterone production in endurance-trained men is suppressed. European Journal of Applied Physiology. 89(2); Pp 198-201. 2003.
“Research indicates that endurance-trained men have lower basal testosterone concentrations than age-matched sedentary control men. It was concluded that the exogenous stimulated testicular production rate of endurance-trained men is suppressed. This finding may account, in part, for the lower circulating basal testosterone concentrations found in these men. The present evidence supports the hypothesis that endurance exercise training induces a degree of peripheral adaptation (i.e., testicle) in the H-P-T axis. Whether this adaptation in the axis is a permanent or transient phenomenon in these men remains to be determined.”
8. Hackeny A, Fahrner C, Stupnicki R. Reproductive hormonal responses to maximal exercise in endurance trained men with low resting testosterone levels. Exp Clin Endocrinol Diabetes. 105(5); Pp 291-295. 1997.
“Resting testosterone (16.6 +/- 2.4 vs. 23.9 +/- 3.1 nmol x 1(-1)) and prolactin (3.3 +/- 1.4 vs. 6.0 +/- 2.0 micrograms x 1(-1)) concentrations in the ET men were significantly lower (p < 0.05) than those in the UT men.”
It becomes apparent that the stress of excessive endurance training can potentially lead to shifts in one’s hormonal profile. “Let’s look at what happens inside the body when stress hits. The body’s initial response to a perceived acute stressor is the fight or flight response. The body’s energy reserves (fat, protein, and carbohydrates) are rapidly mobilized (through catabolic breakdown of tissues) to deal with the stressor. Levels of adrenaline and cortisol increase, while DHEA (dehydroepiandrosterone) and testosterone decrease. (The combined effects of high cortisol and low DHEA lead to muscle loss and fat gain) (28).”
“The dual effect of high cortisol and low DHEA leads to muscle loss and fat gain, but can also have detrimental effects on bone and other tissues (via accelerated breakdown and delayed repair). Typical symptoms associated with chronic stress may include weight gain, fatigue, fluctuations in blood sugar, increased appetite, carbohydrate cravings, muscle weakness, and reduced immune system function. The loss of muscle tissue leads to a fall in basal metabolic rate and marks the turning point between “early” and “late” chronic stress. The early stages of chronic stress can be considered more of a hypercatabolic situation, characterized by accelerated tissue destruction, whereas later stages put a person into more of a hypoanabolic state, where the ability to rebuild vital tissues is impaired. At this later stage, much of the damage has already been done—so muscle and bone tissues are weaker, sex drive is reduced (because of low DHEA, growth hormone, and sex steroids), and the person is entering a vicious cycle of increased appetite, reduced caloric expenditure, and accelerated fat accumulation (28).”
In simplified terms:
Excessive Endurance Training = Increased Potential for Elevated Cortisol + Increased Potential for Overworked Adrenal Glands + Increased Potential for Mineral Deficiency+ Increased Potential for Decreased Testosterone Levels = Increased Potential for Weight/Body fat Gain and ….
Endurance Training and Injuries
In theory, elevated catabolic hormones combined with decreased anabolic hormones can create a potential environment for chronic inflammation, joint stress, joint pain, and potential for injury. Chronic injuries and excessive endurance training seem to go hand in hand. It seems to have become the accepted norm to ingest large dosages of over-the-counter NSAIDS (Ibuprofen or Naproxen) to keep the “the usual” knee, hip, and low back pains in check when training in this manner. Shouldn’t the picture of health be one of freedom from injury, not chronic inflammation and poor immune function. A closer look at the unbiased scientific literature may provide more concrete evidence toward the justification of this “theory”.
1. Cosca DD, Navazio F. Common problems in endurance athletes. Am Fam Physician. 2007 Jul 15;76(2):237-44.
“Common overuse injuries in runners and other endurance athletes include patellofemoral pain syndrome, iliotibial band friction syndrome, medial tibial stress syndrome, Achilles tendinopathy, plantar fasciitis, and lower extremity stress fractures. Endurance athletes also are susceptible to exercise-associated medical conditions, including exercise-induced asthma, exercise-associated collapse, and overtraining syndrome”
2. O'Toole ML. Prevention and treatment of injuries to runners. Med Sci Sports Exerc. 1992 Sep;24(9 Suppl):S360-3
“Many otherwise healthy runners are prevented from participating fully in their chosen endurance sport because of overuse injuries. 2) The most important risk factor for incurring an overuse injury is a training error, such as excessive mileage, sudden change in training distance or intensity, too much hard interval training, improper footwear, and running on chambered surfaces. 3) Although the knee is the most frequent site of injury in runners, any part of the lower extremity may be affected. 4) Tendinitis, muscle strain, and stress fractures are the most common overuse injuries in endurance athletes.”
3. Lehman WL Jr. Overuse syndromes in runners. Am Fam Physician. 1984 Jan;29(1):157-61.
“The increase in strenuous sports participation among adult Americans has led to a high incidence of overuse syndromes. Common running-related problems include iliotibial tract tendinitis, chondromalacia patellae, "shinsplints," stress fractures and various heel and foot syndromes. Most causes of overuse syndromes can be traced to training errors, anatomic factors, poor shoes and uneven running surfaces.”
4. Krivickas LS. Anatomical factors associated with overuse sports injuries. Sports Med. 1997 Aug;24(2):132-46.
“Overuse injuries develop when repetitive stress to bone and musculotendinous structures damages tissue at a greater rate than that at which the body can repair itself. A combination of extrinsic factors, such as training errors and environmental factors, and intrinsic or anatomical factors, such as bony alignment of the extremities, flexibility deficits and ligamentous laxity, predispose athletes to develop overuse injuries. Malalignant of the lower extremity, including excess femoral anteversion, increased Q angle, lateral tibial torsion, tibia vara, genu varum or valgum, subtalar varus and excessive pronation are frequently cited as predisposing to knee extensor mechanism overuse injuries. These and other forms of malalignment have also been implicated in iliotibial band syndrome, medial tibial stress syndrome, lower extremity stress fractures and plantar fasciitis. Muscle inflexibility aggravates and predisposes to the development of a variety of overuse injuries, especially those occurring in children and adolescents, including the traction apophysitises. Flexibility deficits may be improved by an appropriate stretching programme. Unfortunately, lower extremity malalignment is less amenable to intervention. Orthotics are often prescribed to improve lower extremity alignment. However, studies have not shown that orthotics have any effect on knee alignment and, while they can alter subtalar joint alignment, the clinical benefit of this remains unclear. Awareness of anatomical factors that may predispose to overuse injuries allows the clinician to develop individual prehabilitation programmes designed to decrease the risk of overuse injury.”
5. Renström P, Johnson RJ. Overuse injuries in sports. A review. Sports Med. 1985 Sep-Oct;2(5):316-33.
“Trial and error methods of treatment and too little attention to basic research have resulted in less than optimum solutions. We do know that these maladies most frequently result from overload or repetitive microtrauma stemming from extrinsic factors such as training errors, poor performance, poor techniques and inappropriate surfaces or intrinsic factors including malalignment and muscle imbalance. Overuse injuries involving the muscles include compartment syndromes and muscle soreness; while those involving the tendons result from a variety of degenerative and inflammatory processes. Overstress of bone results in stress fractures, apophysitis and periostitis.”
6. Lehmann MJ, Lormes W, Opitz-Gress A, Steinacker JM, Netzer N, Foster C, Gastmann U. Training and overtraining: an overview and experimental results in endurance sports. J Sports Med Phys Fitness. 1997 Mar;37(1):7-17.
“Short-term overtraining called overreaching which can be seen as a normal part of athletic training, must be distinguished from long-term overtraining that can lead to a state described as burnout, staleness or overtraining syndrome. Persistent performance incompetence, persistent high fatigue ratings, altered mood state, increased rate of infections, and suppressed reproductive function have been described as key findings in overtraining syndrome. An increased risk of overtraining syndrome may be expected around 3 weeks of intensified/prolonged endurance training at a high training load level. Heavy training loads may apparently be tolerated for extensive periods of time if athletes take a rest day every week and use alternating hard and easy days of training. Persistent performance incompetence and high fatigue ratings may depend on impaired or inhibited transmission of ergotropic (catabolic) signals to target organs, such as: (I) decreased neuromuscular excitability, (II) inhibition of alpha-motoneuron activity (hypothetic), (III) decreased adrenal sensitivity to ACTH (cortisol release) and increased pituitary sensitivity to GHRH (GH release) resulting in a counter-regulatory shift to a more anabolic endocrine responsibility, (IV) decreased beta-adrenoreceptor density (sensitivity to catecholamines), (V) decreased intrinsic sympathetic activity, and (VI) intracellular protective mechanisms such as increased synthesis of heat-shock proteins (HSP 70) represent a complex strategy against an overload-dependent cellular damage.”
7. Taunton JE, Ryan MB, Clement DB, McKenzie DC, Lloyd-Smith DR, Zumbo BD. A retrospective case-control analysis of 2002 running injuries. Br J Sports Med. 2002 Apr;36(2):95-101.
“Being less than 34 years old was reported as a risk factor across the sexes for patellofemoral pain syndrome, and in men for iliotibial band friction syndrome, patellar tendinopathy, and tibial stress syndrome. Patellofemoral pain syndrome was the most common injury, followed by iliotibial band friction syndrome, plantar fasciitis, meniscal injuries of the knee, and tibial stress syndrome”
8. Burns J, Keenan AM, Redmond AC. Factors associated with triathlon-related overuse injuries. J Orthop Sports Phys Ther. 2003 Apr;33(4):177-84.
“Fifty percent of triathletes sustained an injury in the 6-month preseason at an injury exposure rate of 2.5 per 1000 training hours. Thirty-seven percent were injured during the 10-week competition season at an injury exposure rate of 4.6 per 1000 training hours. Overuse accounted for 68% of preseason and 78% of competition season injuries reported.
9. Egermann M, Brocai D, Lill CA, Schmitt H. Analysis of injuries in long-distance triathletes. Int J Sports Med. 2003 May;24(4):271-6.
“Questionnaires were sent to all German speaking participants of the Ironman Europe 2000. With a response rate of 35 %, 656 questionnaires met the inclusion criteria. At least one injury was experienced by 74.8 % (95 %-CI: 71.3-78.1) of all respondents during their active time in triathlon. 51.1 % (95 %-CI: 47.2-55.0) suffered one or more contusion/skin-abrasions, 33.1 % (95 %-CI: 29.5-36.8) muscle-/tendon-injuries, 29.0 % (95 %-CI: 25.5-32.6) ligament-/capsule-injuries and 11.9 % (95 %-CI: 9.5-14.6) fractures.”
10. Shaw T, Howat P, Trainor M, Maycock B. Training patterns and sports injuries in triathletes. J Sci Med Sport. 2004 Dec;7(4):446-50.
“At least one injury was reported by 37% of the participants. The most frequently affected sites were the ankle/foot, thigh, knee, lower leg and the back. Overuse was the reported cause in 41% of the injuries, two-thirds of which occurred during running. The likelihood of an injury was positively associated with experience in triathlon. Average injury rate was 5.4 injuries per 1000 h of training (95% confidence interval: 4-7.2) and 17.4 per 1000 h of competition (95% confidence interval: 10.9-27.9). Injury incidence was unrelated to the mean amount of weekly training or competition, intensity or frequency of training.”
11. Gudas CJ. Patterns of lower-extremity injury in 224 runners. Compr Ther. 1980 Sep;6(9):50-9.
“Knee problems are the most common injury sustained in both male and female runners. Other problems include toe and forefoot injuries, inferior heel and arch pain, shin splints, ankle pain, calf and Achilles tendon pain, groin and hip pain, and stress fractures. The average total treatment for all injuries required 4.2 physician visits. Orthotics were used for more than 60% of the injuries, with successful results “
12. Pinshaw R, Atlas V, Noakes TD. The nature and response to therapy of 196 consecutive injuries seen at a runners' clinic. S Afr Med J. 1984 Feb 25;65(8):291-8
“We studied a series of 196 running injuries to determine the nature of the common injuries, the type of runners with the different injuries, specific factors causing the most common injuries, and the response of these injuries to correction of the biomechanical abnormalities believed to cause them. The four commonest injuries were 'runner's knee' (peripatellar pain syndrome) (22%), 'shin splints' (posterior tibial stress syndrome) (18%), the iliotibial band friction syndrome (12%), and chronic muscle injuries (11%). Within 8 weeks of following the biomechanically based treatment regimen, between 62% and 77% of the runners with the commonest injuries were completely pain-free and running almost the same training distance as before injury. Only 13% of runners were not helped at all, but most of these had not adhered to the prescribed treatment.”
In all, there have been over 1000 scientific studies on injuries and endurance training. This fact alone should be cause enough for a reevaluation of who should partake in excessive endurance training and who should not. The recommendation for complete or periodic cessations as well as alternatives to the activities should be emphasized more frequently as the activity itself can at times be found as causation for the chronic injuries. For more scientific based information on endurance training and overuse injuries, click on the on the following links 445 studies on common problems in endurance athletes , 112 studies on overuse injuries in runners , 518 studies on common injuries of triathletes , 261 more studies on common injuries of runners .
What are the alternatives, as excessive endurance training for people with less than optimal health lead to a greater potential for negative health effects? What about strength training? Does strength training provide greater losses in body fat?
· Lindegaard B, Hansen T, Hvid T, van Hall G, Plomgaard P, Ditlevsen S, Gerstoft J, Pedersen BK. The effect of strength and endurance training on insulin sensitivity and fat distribution in human immunodeficiency virus-infected patients with lipodystrophy. The Journal of Clinical Endocrinology & Metabolism. 93(10); Pp 3860-9. 2008.
“Only strength training increased total lean mass 2.1 kg [95% confidence interval (CI), 0.8-3.3], decreased total fat 3.3 kg (95% CI, -4.6 to -2.0), trunk fat 2.5 kg (95% CI, -3.5 to -1.5), and limb fat 0.75 kg (95% CI, -1.1 to -0.4). Strength training significantly decreased total and limb fat mass to a larger extent than endurance training (P < 0.05). This study demonstrates that both strength and endurance training improve peripheral insulin sensitivity, whereas only strength training reduces total body fat”
In other words, “strength training—which primarily involves lifting weights—leads to greater loss of total body fat than endurance training.” Strength training can also lead to increased levels of testosterone, allowing the body’s tissues to rebuild and recover. The strengthening of weak musculature can lead to structural balance between antagonistic muscle groups, which can dramatically decrease the risk of chronic or acute injury, as well as increase performance due to proper muscular firing patterns, rather than relying on compensatory actions.
When partaking in strength training, excessively trained endurance athletes need to recognize the danger in applying the common “no pain, no gain” mentality found in endurance sports. When this mentality is applied to weight training, especially in an endurance athlete expressing the symptoms of chronic endurance overtraining (as we learned above: elevated cortisol levels, decreased DHEA and testosterone levels, potential mineral deficiencies, potential for adrenal fatigue, and potential cumulative trauma from improper biomechanics), the potential for injury is very high. A proper structural balance evaluation should be of priority before partaking in any strengthening activities for this classification of athlete, as the risk of injury may be too high if approached blindly.
Perhaps a reduction in volume or intensity of endurance training may help to alleviate some of the unwanted symptoms of excessive training. Lower impact workouts, interval and Tabata methods, modified strongman workouts, as well as recreational sporting activities have all been shown to be beneficial to one’s health, assuming the excessively trained endurance athlete allows for correct technique, modifications in the intensity paradigm, cessation of exercise upon breakdown of technique, and of course, proper rest and recovery to avoid problematic symptoms of overtraining.
Lifestyle and dietary modifications can also help to alleviate these symptoms. Some of these may include increasing protein intake (if too low), post workout recovery shakes/meals, avoidance of foods causing allergies or inflammatory responses, testing for and correcting mineral or vitamin deficiencies, increasing intake of antioxidants (if necessary), a properly performed detoxification, and comprehensive blood, amino acid, and toxic load testing. Biosignature Modulation is a great tool for any athlete/fitness enthusiast looking to increase their physical health while decreasing their unwanted body fat.
If chronic injuries do currently exist, ART (Active Release Technique), Acupuncture/Accu-pressure, Rolfing, or even simple self myofascial release techniques have been shown to alleviate even some of the most stubborn of chronic symptoms associated with excessive endurance training.
Basically what it comes down to is WHY ARE YOU PARTAKING IN EXCESSIVE ENDURANCE TRAINING? After answering this question, self education (not just what is put out there in mass media) can be the most powerful tool toward achieving whatever physical goal you may have set for yourself. Until then, know that it is OK to hop off the sweaty treadmill or elliptical for a few workouts, and pick up a weight or perhaps go outside for leisurely low cortisol inducing walk and allow your body to recover, rebuild, and repair.
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