Don’t kill the pain of exercise

Don’t kill the pain of exercise
If you do the same sport for too long or too hard, you are bound to pick up an overuse injury at some point. Or in our sport a momentary lapse of concentration or co-ordination could have you kissing the dirt leaving you with some nasty war wound. But like a true sports warrior, the drive to keep up the training miles or the temptation to head out on a long-planned event promising fantastic views, untouched forests and thrilling track is all too much to forgo despite the nagging pain with every pedal stroke that shouts: STOP!!! Where has the long-last motto “listen to your body” gone? Instead we go by: “Shut it up with a pill and keep going”. How do pain pills work?
Most over-the-counter painkillers and anti-inflammatories, classed as nonsteriodal anti-
inflammatory drugs (NSAIDs), work by targeting an enzyme called COX which
produces substances called prostaglandins. When prostaglandins are about they heighten
the sensation of pain associated with inflammation. Prostaglandins also increase the
degree of inflammation at the site of injury by increasing blood flow to the site and
making blood vessels in the area porous to white blood cells that are recruited as the fix-it
team. So blocking prostaglandin synthesis with NSAIDs brings some relief from pain,
stiffness and swelling.
Which NSAID have you used?
Some of the common NSAIDs that we have all swallowed at some point include:
Diclofenac (Voltaren), ibuprofen (Ibumol, Mypaid, Myprodol, Betagesic), ketoprofen
(Actron, Orudis KT), naproxen (Aleve), mefenamic (Ponstan) are the newer NSAIDs that
tend to have greater effect at the injury site to bring down swelling than more classical
drugs.
Aspirin (medical name- salicylic acid) is an age-old NSAID still in use. It also acts on
COX enzyme to block prostaglandin production but by a unique mechanism that changes
the shape of the active site of COX rendering it useless.
Then there is paracetomol (Panado), which has a spot on everyone’s medicine shelf and
we are sometimes fairly blasƒ about self-medicating with these- if pregnant women can
take these it must be harmless? Paracetamol operates by moping up perchloric acid which
is necessary for COX activation. However at the injury or inflammatory site the white
blood cells secrete copious amounts of perchloric acid and this swamps paracetomol
without significantly reducing COX production of prostaglandins. Paracetomol is
however great at reducing brain prostaglandins and thereby decrease the pain signal sent
out from the brain. Thus paracetomol is not first on your list to bring down swelling but
will ease the pain. Some drugs are a combination of the newer NSAID with a dash of
paracetomol for dual function of reducing swelling and extra pain relief.
Exercise changes blood flow
While NSAIDs have their place they are possibly not a good mix with exercise. One of
the major changes that happen when you exercise is a redistribution of blood flow: less to
central organs (except the heart) and more to exercising muscles and the skin. While at
rest liver, kidneys and muscles all receive roughly 1L blood per min, when you exercise
at a moderate intensity liver and kidneys receive only 0.6 L per min while muscle blood flow increases to 12.5 L per min. This is the basic primary concern of mixing medicine and exercise. The liver and kidneys are crucial for regulating drug metabolism and excretion. With less blood passing through these organs, whichever pill you swallow is likely to remain active for longer and effectively ups the pharmacological concentration present in your system. There’s more… Three reasons why NSAIDs do not mix with exercise
1. Kidney phenomenon
Prostaglandins are involved in increasing blood flow to muscle and kidneys helping to maintain kidney function under the stress of decreased blood flow during exercise. So when you take a NSAID before your ride, prostaglandin production is suppressed and cannot play its role to keep your kidneys working optimally. The net result is a decreasein the amount of water lost to urine. This may not sound so negative but if this forced water saving is combined with a thorough drinking schedule you are a prime risk candidate for suffering from potentially fatal exercise associated hyponatremia (EAH)- in plain English, over-diluted sodium that causes your brain to absorb water and swell. Evidence from ultra-endurance events, such as marathons and iron-man triathlons shows that the athletes suffering from EAH during the event where mostly those taking NSAIDs during the race. In fact if prostaglandins were active (i.e. not blocked by NSAIDs) then they could help to prevent EAH when sodium content is low by stimulating hormones in the kidney that reduce extra sodium loss to urine.
NSAIDs when combined with exercise have other gremlins hidden in the closet that wreck havoc during exercise.
2. Leaky gut and oxidative stress
In a recent study, ultra-marathon runners heading out on a 160 km race took ibuprofen the day before and during the event at recommended doses. Evidence of oxidative stress was measured in blood and urine at the finish was compared to those athletes who never took NSAIDs. Oxidative stress was 17% higher in NSAID users- almost double than detected in the nonusers. Higher oxidative stress implies greater damage to cell structure and, liver and kidneys are probably most at risk. A study administering paracetomol to rats during exercise found evidence of liver damage. Not good for long term prognosis. Why the higher oxidative stress during exercise with NSAIDs? Prof. McAnultyspeculates that there are 3 possible explanations: Decreased blood flow to the liver during exercise will hinder breakdown of the drug, and impede detoxifying pathways. Or else the drug could directly influence an important enzyme involved with the metabolism of oxygen. Alternatively, horror of horrors, the theory which Prof. McAnulty favours is that NSAIDs cause essentially gut leakiness and allows bacterial cells to filter into your blood causing endotoxemia. This sure isn’t far fetched as aspirin and to a lesser extent ibuprofen taken during exercise increases gut permeability to other substances; in one particular study sugars and in another study, wheat allergens. Well there goes my trusty racing energy drink- it contains “white willow bark” AKA aspirin. I’m now in the market looking for a new race mix.
3. NSAID for puny muscles
As a final blow NSAID undoes all your hard training to stimulate muscle growth and paradoxically delays recovery of exercise-induced injured muscle fibres. The evidence is fairly conclusive that the rate of muscle protein synthesis following weight training is blunted by NSAID. Muscles used in training become progressively stronger as they are stimulated to adapt by the mechanical stress of exercise which causes micro-injury of fibres. Thus muscle regeneration and repair is a constant requirement in athletic muscles which involves influx of inflammatory cells that remove debris and recruit various inflammatory mediators such as prostaglandins and growth factors to the worked muscles. The regeneration process is sequential and each phase is dependent on the previous, so if you block the prostaglandins that promote inflammation this may delay healing and prevent growth. A group of fellows swallowed either ibuprofen or paracetomol or “blanks” and then went to the gym to do a few set of heavy leg curl lifts. The next day they allowed a nutty scientist to zap a tiny section of their muscle. They found protein synthesis rate to be up by 76% in the guys who only swallowed “smarties” but essentially no extra protein synthesis was occurring in the fellows who took ibuprofen or paracetomol. Moreover, all of them were pretty darn sore and could barely move the day after; NSAIDs did not prevent post exercise pain either. Then some super-duper athletes competed in a 36km run. At the finish they very generously donated a tiny muscle section to another nutty scientist who discovered that runners who never took NSAIDs in the run had evidence of activated stem cells (undifferentiated cells) ready to move in and regenerate and grow tired muscles. Whereas those popping NSAID during the run had no activated stem cells- bummer! Following the finding of this study, Prof. Mackey goes by the saying, “no pain, no gain”. In a nutshell, don’t expect to ever get bulging quadriceps like Tom Boonen if you go popping NSAIDs.
NSAID massage
If you can’t swallow a pill, how about a nice massage with Deep Heat or the like? Deep
Heat, Voltaren Emulgel, Reparil-Gel and the like are all NSAID based creams. Voltaren
Emulgel is diclofenac based and other ibuprofen and ketoprofen (Fastum gel) based
lotions or patches are absorbed through the skin but only a quarter of the equivalent oral
dose will penetrate to muscle level. At rest absorption into the bloodstream is only 5-10%
of an oral dose and excretion in urine is low. Exercise however increases skin and muscle
blood flow which will increase the amount of drug absorbed into your blood. Naturally
larger amounts applied over extensive areas of skin will increase systemic absorption. On
the other hand, sprays and creams such as Deep Heat or Icy Hot contain methyl salicylate
(i.e. aspirin-based) and these appear to have greater absorption into circulation with 15-
22% appearing in urine in the first hour. Exercise increases this uptake by 3-fold. Once
the drug is in your bloodstream it will carry the same risks as when originating from a pill. To be prudent, I would recommend avoiding these NSAID lotions during exercise. Everyday use post-exercise may also be counterproductive in terms of muscle regeneration and growth. NSAIDs-spiked with codeine-Beware!
Ever met anyone gulping Myprodols halfway into a race- I’ve heard of someone who has! Some NSAID preparations add a dash of codeine for maximum pain-relief and comfort, such as Myprodol, Mypaid, Stopyne etc. Codeine is a different class of painkiller to NSAIDs, it is an opiate along with morphine. In fact codeine or methylmorphine as it is correctly known is partly converted in the liver to morphine. They inhibit pain by acting on receptors in your spinal column where the pain signal from your throbbing muscle is first received before it goes up to your brain to set of the “I’m sore alarm”. Unfortunately codeine also leaves you feeling a little dopey. A dopey feeling is not going to get you from start to finish in one piece. Let’s just leave it at that.
The pill or your bike, you choose?
Oh the ache, you can’t bear it! What can you do to stop the ache? If it’s so bad that it
sends you rummaging through your medicine cupboard for a pill, then best you stay of
the bike!
References
Bandolier. Topical NSAIDs: plasma and tissue concentrations.
Farquhar WB et al. (1999) Effects of acetaminophen and ibuprofen on renal function in
the stressed kidney. Journal of Applied Physiology 86: 598-604.
Mackey AL et al. (2007) Use of anti-inflammatory medication in healthy athletes- no
pain, no gain? Scandinavian Journal of Medicine and Science in Sports 17: 613-614
McAnulty et al. (2007) Ibuprofen use during extreme exercise: Effects on oxidative stress
and PGE2. Medicine and Science in Sports and Exercise 39:1075-1079.
Morra P et al. (1996) Serum concentrations of salicylic acid following topically applied
salicylate derivatives. Annual pharmacotherapy 30: 935-940.
Tegeder I et al. (1999) Application of microdialysis for the determination of muscle and
subcutaneous tissue concentration after oral and topical ibuprofen administration. Clinical
Pharmacological Therapy 65:357-368.
Trappe et al. (2002) Effect of ibuprofen and acetaminophen on postexercise muscle
protein synthesis. American Journal of Physiology 282: E551-E556.

Source: http://www.enervit.co.za/articles/RIDE_NSAID.pdf