Medications and Endurance Training: What You Should Know

Recently, a drug rep was in our clinic telling me how their pain medications would be good for the pains commonly experienced by athletes. I immediately thought about the importance of this topic and figured I better share some words on the blog about it. Not all primary care docs, nurse practitioners, and PA’s are familiar with the unique physiology of endurance athletes. It is important to take this into consideration when considering taking certain medications.

For this post, I am only going to cover common pain medications (both OTC and prescription) and antibiotics.

Over-the-Counter Pain Relievers

In a study conducted in 2007, runners took either aspirin (650mg), ibuprofen (400mg), or a placebo 24 hours prior to running 60 minutes on a treadmill at 70% VO2max. Researchers found that both ibuprofen and aspirin increase gastric permeability. Aspirin also increases small intestine permeability. In laymen’s terms, this means you are not absorbing nutrients as well, or you have a mild “leaky gut”. Some of the carbohydrates you take in during your race/training will not be absorbed.

Increased gastric and intestinal permeability can lead to gastrointestinal (GI) discomfort. There is also evidence that NSAID use during intense exercise can increase GI bleeding, which is somewhat common in triathletes who incorporate a significant amount of intensity to their training. Increasing blood loss through the GI system often leads to a decrease in hemoglobin and red blood cells, and is a common cause of anemia in triathletes.

For general health, it is best to avoid these prior to prolonged exercise. However, I must avoid bias here and share the entire story. There is research suggesting that acetaminophen can aid performance. As pain perception increases our speed decreases. Research exists that shows that in short events, such as a short cycling time trial, reducing the pain by taking an OTC pain reliever may result in cyclists riding faster due to the lack of pain. However, in long events, NSAIDs, aspirin, and acetaminophen have generally been shown to be unsafe and have little to no positive effect on performance.

A study performed on Ironman distance triathletes several years ago found an increased risk of exertional hyponatremia due to altered kidney function when taking NSAIDs. NSAIDs increase the effect of anti-diuretic hormone, causing the kidneys to retain water and thus diluting sodium levels. Similar findings have been found in newer studies. This complication is especially concerning if it is hot and humid on race day.

OTC Pain Reliever Summary
Although acetaminophen use may be very slightly beneficial to performance in very short events, OTC pain relievers are generally not a good idea. Acetaminophen in high doses can cause liver damage. It is unlikely that an athlete would take the sort of dose to cause acute liver damage (approximate dose in adult is 8,000 mg in 24 hour period in “normal adult”). However, in long distance training and racing, the liver is typically burdened. In fact, in nearly every professional endurance athlete I perform blood tests on I am seeing high liver function numbers, meaning the liver is “stressed”. Although this topic has not been studied much, we do know that a risk factor for liver damaging side effects from acetaminophen is a history of liver conditions. The stress your liver endures in a long distance event may be enough to be considered a predisposition for acetaminophen toxicity. I can’t say this with conviction, as I have not seen any research on it, but it sure makes sense and is not something I would personally risk.

For long distance triathletes, NSAIDs can be detrimental to performance, and even be dangerous. You are better off avoiding them. Although, if there is simply no other option and/or you are one of those people whose opinion is “I’ve been doing this for years and I haven’t had a problem yet, so no matter what you say I’m still taking my OTC meds”, acetaminophen is likely the safest. The fear of hyponatremia (abnormally low sodium concentration in blood) is a very real risk, and a big enough risk for many experts, myself included, to consider NSAID use for ultra-distance events (ex. Ironman) an absolute “no-no”. Hyponatremia can result in brain swelling, brain herniation, cardiopulmonary arrest, seizures, coma, and even death in severe cases. Think this can’t happen to you? You better think again. Researchers found that 13% of 2002 Boston Marathon finishers were clinically hyponatremic. Yep, that is after a marathon…and not one that came after swimming 2.4 miles and biking 112.

Prescription Pain Relievers

Muscle Relaxants – Muscle relaxants should be discontinued a couple days before competition and should never be taken just prior to competition or training. Ideally, an endurance athlete would not take them at all. However, these are very commonly prescribed and some endurance athletes find them helpful for injuries not sustained from running, biking, or swimming. The biggest danger with muscle relaxants is the side effects. They are CNS depressants and common side effects include drowsiness and dizziness. Regarding performance, it would be awfully tough to have a good race when you feel drowsy. Regarding safety, drowsiness and dizziness can be an issue when you are competing in a race where common side effects of the race itself are dizziness and lightheadedness. Falls are a concern.

Vicodin – Vicodin is a combination of acetaminophen and hydrocodone. Vicodin is indicated for moderate to severe pain. Put simply, Vicodin is not for the training athlete, except in VERY special circumstances and under VERY careful guidance. If you think you may be one of those VERY special circumstances, be sure to speak with a doctor familiar with the physiological demands of training for whatever event you are training for.

Percocet – Percocet is a combination of acetaminophen and oxycodone. Similar to Vicodin and my opinions are the same. See Vicodin for more information.

Celebrex – Celebrex is a strong NSAID. Bottom line, don’t use it if you are an endurance athlete. There are better alternatives if absolutely needed.

Solutions for Pain

If the pain is localized, be sure to consider a topical cream based pain reliever. Topical pain relievers provide adequate pain relief for many of the conditions experienced by endurance athletes, such as tendinopathy’s and minor sprains/strains. Topicals can also be compounded to include both pain relievers and anti-inflammatory medications. By using topical creams you are bypassing the GI system, and less medication is absorbed into the bloodstream to be filtered through the liver. Topical cream based pain relievers are my choice for localized pain relief when needed.


There are times when antibiotics are needed. As an athlete, nothing is more frustrating than being ill. Not only do you feel terrible, but you are also missing out on valuable training time. However, before your impatience leads to a hasty decision to take antibiotics, make sure the illness is truly bacterial. Why? Because antibiotics come with a price on functional health.

There are many studies that show the negative effects of antibiotics on the vital microflora (probiotics) in our guts. A recent study shows that following a single short course of ciprofloxacin certain strains of probiotics are still not recovered 6 months following the treatment! Yikes. The microflora in your gut appears to have a connection with micronutrient absorption. Certain micronutrients are essential to red blood cell production, cellular functions, and certain critical components of recovery following workouts.

There appears to be evidence in favor of taking probiotics following the completion of antibiotics. However, probiotics are much more complicated than simply going to your local grocery store and buying a bottle that reads “Probiotic”. There are many strains of probiotics, and research has yet to determine how to best supplement them. How probiotics are prepared, bottled, their source, etc, etc all make a difference in their viability. Choosing a quality company is important. If you are looking for a quality probiotic, send me an e-mail at garretrock1 at gmail dot com (yes, I don’t want spam so I spelled my e-mail address out on purpose…beware of those internet robots).

Happy training!


Lambert GP, Boylan M, Laventure JP, Bull A, Lanspa S. Effect of aspirin and ibuprofen on GI permeability during exercise. Int J Sports Med 2007 Sep; 28(9); 722-6. 

Piatkowski TS, Day WW, Weiner M. Increased renal drug metabolism in treadmill-exercised Fischer-344 male rats. 1993 May-Jun; 21(3): 474-9.

Mauger AR, Jones AM, Williams CAInfluence of acetaminophen on performance during time trial cycling. J Appl Physiol. 2010 Jan;108(1):98-104. 

Rudzki SJ, Hazard H, Collinson DGastrointestinal blood loss in triathletes: it’s etiology and relationship to sports anaemia. Aust J Sci Med Sport. 1995 Mar;27(1):3-8.

Wharam PC, Speedy DB, Noakes TD, Thompson JM, Reid SA, Holtzhausen LM. NSAID use increases the risk of developing hyponatremia during an Ironman triathlon. Medicine and Science Sports and Exercise. 2006 Apr; 38(4): 618-22.

R. E. O. Williams, M. J. Hill, and B. S. Drasar. The influence of intestinal bacteria on the absorption and metabolism of foreign compounds. J Clin Pathol Suppl (R Coll Pathol). 1971; 5: 125–129. 
Dethlefsen L, Huse S, Sogin ML, Relman DAThe pervasive effects of an antibiotic on the human gut microbiota, as revealed by deep 16S rRNA sequencing.  2008 Nov 18;6(11).
Written on June 30, 2016
By Garret Rock

Hey Endurance Athletes, Want Your Testosterone Back?

It’s no secret that endurance training can lead to reductions in testosterone. Theories behind the reduction of testosterone during endurance training previously revolved around the loss of body mass, increased cortisol levels, and changes in luteinizing hormone. However, there is some debate around this, and the mechanism is not 100% clear. Nonetheless, the reduction of testosterone can have a mildly negative impact on recovery from training and a big impact on your quality of life.

Drops in testosterone can result in decreased libido, mood changes, decreased energy, and prolonged recovery from workouts. There are several more symptoms, however these are the most relevant to endurance athletes.

Testosterone decreases appear to be correlated to the amount and intensity of training. The general rule of thumb is, the longer you train each week, the lower your testosterone level. Interestingly, resistance training, such as lifting weights, increases testosterone, while endurance training decreases testosterone. Research has yet to answer some questions regarding this difference. If I may throw in a completely subjective opinion, I will say that when something like this occurs naturally, there is typically a reason, and that reason is protective against a detrimental consequence. However, for now we must work with the body of evidence we have, and that appears to suggest that lower testosterone negatively affects performance.

Testosterone supplementation and hormone replacement is banned in sports. Yes, even for amateurs. Of course, some discretion should be used here. If you are a middle of the pack age grouper without a shot at placing within your age group, your relationship with your wife is hurting because of decreased libido and mood, and you are struggling to be as productive as you should be around the house because of your lower energy, well, the answer of what to do seems obvious. But, cases like this have not been addressed by USADA yet, and the substance is simply banned in sanctioned events. However, if you are a top age grouper, I would strongly advise you against even considering testosterone, unless you may qualify for a therapeutic use exemption (no, “my wife wants me to go on testosterone” does not qualify you for an exemption). Recent evidence has found a high incidence of “cheating” among master’s and age group athletes, and testing on this population is likely to become routine in the future for top age group finishers. In fact, it has already started. Pro’s don’t even stand a chance, they will be caught.

Fortunately, there are interventions that may increase testosterone naturally. Here are some of the most effective.

  • Strength Training – adding in a day or two a week of strength training is one of the most effective ways to boost testosterone. If you can keep the intensity high that can further enhance the effects. Do intense 1-2 minute bursts of weight lifting.
  • Zinc – zinc is one of those “tricky” micronutrients in endurance athletes. It is involved in several important pathways that tend to be “used in excess” during training. Therefore, it is often lower than normal in endurance athletes. Zinc is important in testosterone production. Studies show that zinc supplementation may increase testosterone levels. On a related note, if you supplement iron at any point in your training (and if you do make sure you read my blog post about this), this can cause a reduction in zinc absorption, and thus a decrease in testosterone production. Zinc should be supplemented during iron supplementation. Supplementing zinc at low levels is generally recommended for endurance athletes training more that 8 hours per week.
  • Reduce Sugar Intake – testosterone levels decrease after eating sugar. Diets high in sugar have been associated with reduced testosterone levels in some small studies.
  • More “relations” – having “relations” more frequently increases testosterone levels. Kind of a catch 22.
  • Eat Fats – fats are essential to testosterone production. This includes both healthy fats (avocados, fish oils) and saturated fats (yep, the ones we have been told are terrible for us all of these years). Studies show that increased fat intake may be correlated to increased testosterone. Now you have an excuse to eat bacon one day a week!
  • Eat eggs – egg intake is shown to increase DHEA-S, which in turn leads to more testosterone.
  • Get enough protein – endurance athletes should at least consider supplementing whey protein during peak training. This should be considered on an individual basis. However, most athletes could benefit from this, and it can help maintain higher testosterone levels.
Written on
By Garret Rock

Athlete Thermoregulation: Tips for Keeping Cool When It’s Hot


Thermoregulation is the ability of an organism
to maintain a body temperature within certain boundaries, even when the
surrounding temperature is very different. Basically, this refers to your ability
to stay warm in cool environments, and cool in hot environments. A
physiological example of thermoregulation is sweating.
The concept of thermoregulation is important to
endurance athletes because it directly correlates to performance. The inability
to control temperature swings results in a decrease in performance, and can put
an end to your race day altogether. This decrease in performance is hardly
negligible, just look at the following statistics from a study on marathon
  • In elite pro runners, for every 5 degrees over 41
    degrees Fahrenheit, times slow by 0.4%. On a 77 degree day, an elite
    pro will expect to run 5% slower than on a 41 degree day.
  • The rate of slowing increases with slower run times.
    For example, in this study, they found that a 3 hour marathoner will be
    around 12% slower on a 77 degree day compared to a 41 degree day. This
    brings their finish time from 3 hours flat to 3 hours 21 minutes.
Fortunately, there are small steps we can take
to battle the performance deficits that come with hot temperatures. Here are four
of the most effective methods for avoiding over-heating during training and
Hydration is your first line of defense in
thermoregulation. Although on the surface hydration seems simple, how you
hydrate and what you hydrate with can actually have a big impact on
thermoregulation and hydration status.
Laboratory based tests conclude that
hyperhydration is an effective strategy for maintaining a slightly lower body
temperature during endurance exercise in hot temperatures. Hyperhydration, put
simply, is preventatively taking in fluids, or drinking when you are not
thirsty. This effect seems to be due to a faster onset of sweating and improved
“sweating efficiency”. For shorter races (1-3 hours), hyperhydration
does appear to be an appropriate strategy on a hot day. Exactly how effective
this strategy is in improving performance is yet to be determined at these
distances, but theoretically benefits do exist, as research definitely shows
improved thermoregulation through hyperhydration.
One way to enhance hyperhydration without having
to chug down as many bottles of water is to nutritionally optimize
intracellular fluid uptake. One supplement that aids this is glycerol, yep that evil alcohol sugar. Before undertaking glycerol supplementation for hyperhydration, be sure to do your research, or better, work with a professional that knows what they are doing. Done right, you win. Done wrong, you lose. In addition, during exercise,
plain water is fairly poorly absorbed in the intestines. Including
carbohydrates in a fluid replacement drink is crucial for optimal fluid
absorption in the intestines. In fact, research shows that combining a
carbohydrate with water during exercise improves intestinal fluid absorption up to
six times!
Action Step: I recommend using a sports
drink as your primary hydration source always.
On exceptionally hot days, I recommend drinking 25 ml/kg body weight (175 lb
person will drink approximately three 21 oz bottles) of fluids prior to the
race. Make two of them water and one a sports drink. Be sure to use electrolyte tabs as
directed during the race to ensure adequate electrolyte levels. 
There is not much science to be found on the
effect of water dousing on core temperature during exercise, however anecdotal
“evidence” strongly supports frequent water dousing during a race in
the heat. Fortunately, many races in hot environments now provide sponges and
cups of ice for dousing.
Action: At each aid station be sure to douse yourself
with water and/or ice/sponges. This is typically only needed during running, as
the wind during biking is typically enough to evaporate sweat quickly.
Your choice of clothing impacts thermoregulation.
Sweating is the body’s natural cooling method. However, in order for sweating
to be effective, the sweat must evaporate. It is the evaporation of sweat that
cools the body. The ideal clothes for training and racing in hot weather allow
for air to flow through them. On sunny days, protecting the skin from the sun
is beneficial to staying cooler. Sunscreen can interrupt both sweat production
and evaporation. Although dark colors do absorb more heat when the sun is out,
in a short race this is unlikely to result in hotter core temperatures.
However, in a long race, opting for the lighter color is likely the wiser
decision. On sunny days, wearing a visor to protect from the sun and save on
sunscreen use is the wiser choice.
Action: In a running race, wear light, loose clothing.
If the sun is out in force, choose light colors. In a triathlon or cycling
race, choose a kit made of breathable material. Choose coverage with the light apparel over sunscreen for most of your body. 
On hot days, pre-cooling appears to mildly
improve performance in endurance races. For long and ultra races (Ironman,
70.3) this may not provide much performance enhancement. However, in shorter
duration races (marathons, half marathons, 10K’s, 5K’s, sprint tri’s, and
olympic tri’s), pre-cooling appears to benefit performance and thermoregulation
on hot days. Pre-cooling may include staying cool in the water prior to a
triathlon (if chilly), wearing a cooling vest during your warm up (, or sitting
in a cool environment. Basically, be chilled just prior to the race. But don’t
neglect an appropriate muscle warm up.
Action Step: Either
perform your pre-race warm up in a cooling vest, or perform your pre-race warm
up, then find a cool environment to sit in and get chilled (air conditioned car, water for a triathlon, or building close by). Being you’ll be sweating, the cool air will evaporate
the sweat well and result in rapid cooling.
Questions?  Contact us at  You can also shop our Panels at:

Michael N. Sawka; Lisa R. Leon; Scott J. Montain; Larry A. Sonna
Integrated physiological mechanisms of exercise performance, adaptation, and maladaptation to heat stress 
Comprehensive Physiology 2011;1(4):1883-1928.

Eur J Appl Physiol Occup Physiol. 1987;56(5):603-7.

Thermoregulation in hyperhydrated men during physical exercise.

Grucza R, Szczypaczewska M, Kozłowski S.


Department of Applied Physiology, Polish Academy of Sciences, Warsaw.
Br J Sports Med. 2006 April; 40(4): 320–325.


doi:  10.1136/bjsm.2005.022426


Core temperature and hydration status du
ring an Ironman triathlon

P B Laursen, R Suriano, M J Quod, H Lee, C R Abbiss, K Nosaka, D T Martin, and D Bishop
Written on
By Garret Rock

Triathlete Training Podcast Interviews Garret Rock About Blood Monitoring for Endurance Athletes

I recently was a guest on the Triathlete Training Podcast (, where I was interviewed on blood monitoring for the endurance athlete. We discuss why, what, how, and when.

Simply hit play on the mini player shown just above to listen. Enjoy!

Here is the preamble from the Triathlete Training website:

Blood Monitoring

Garret Rock joins the show.  Garret is an exercise physiology specialist and Doctor of Chiropractic and sports nutrition specialist.  He does blood testing for both age group and professional triathletes.  He has done over 800 blood tests on professional triathletes.

His services are available through and he works at South Pointe Clinics in Colorado.  He charges roughly $120-$170 per analysis.

During the interview he gives an example of work he has done with Liz Blatchford. Liz finished third at Ironman Hawaii in 2013.  Over the course of several weeks Liz made the following changes in her blood measurements:

Test #1
2 Weeks Later
10 Days Later
3 Weeks Later
Liz was feeling fine when she had her first blood test, but Garret noticed a folate deficiency. With his help, which included some creative smoothie recipes that included beets and other not-so-tasty ingredients, Liz was able to make significant improvements in her hemoglobin and hematocrit levels.
Written on
By Garret Rock