NSAID tablets (ibuprofen, naproxen, diclofenac and others)
NSAIDs, Ketoprofen, Meloxicam, Celecoxib, Etoricoxib, Nimesulide, Aceclofenac, Indomethacin
Forms: Ibuprofen, naproxen, diclofenac, ketoprofen, nimesulide and others; COX-2-selective celecoxib and etoricoxib are gentler on the stomach but not on the heart. Aspirin and NSAID gels have their own cards.
Health support (prescription)Over the counter (varies by country)Evidence: approved medicine
Anti-inflammatory painkillers in tablets, capsules or powders — the most used medicines in sport. They ease pain but can harm the stomach, kidneys, blood pressure and heart, and pain relief can hide an injury.
Legal status: Low-strength ibuprofen, naproxen and some others are sold without prescription in many countries, other forms need one; varies by country. Not on the WADA list.
What it gives
What people use it for and what the sources report. Strength is a general category from the literature: mild, clear or strong.
Purpose
Taken for joint, tendon and muscle pain, injuries and soreness, often before training or races to stay ahead of pain. Medical use: pain, inflammation, arthritis, fever. Sports-medicine reviews find no evidence for taking them in advance and advise use only when needed and as briefly as possible.
What people seek and what studies show
They ease pain and inflammation for a while but do not improve performance — the reason WADA does not ban them. In young adults doing leg training, maximal over-the-counter ibuprofen intake halved muscle growth compared with low-dose aspirin (3.7% vs 7.5%). Among marathon runners, those who took painkillers before the race had about five times more adverse events.
Effects
Evidence: Approved medicine — studied in people for its medical use
Possible side effects
Possible does not mean certain: whether they appear depends on dose, duration, individual response and monitoring. Below — what to watch for and how to notice it early.
9 possible side effects
level · how often it is reportedElevated
Bleeding risk (bruising, stomach or brain bleeds)
possibleStomach and gut bleeds were two to four times more common than on placebo in trials; more so with aspirin, corticosteroids or alcohol. Black stools or vomiting blood need urgent care.
How to notice: Easy bruising, nosebleeds, bleeding gums, tiny red dots on the skin, cuts that bleed longer than usual.
Elevated
Kidney strain
possibleThey cut kidney blood flow when fluid is short: in desert ultramarathons acute kidney injury hit 52% on ibuprofen vs 34% on placebo. Weight cuts, heat and diuretics add to it.
How to notice: Usually silent; foamy urine or swelling in later stages. Big muscle mass or creatine also raise creatinine.
Elevated
Heart strain / heart-muscle thickening
rareHeart attack and stroke risk rises, possibly early in use; heart failure was about doubled in trials. Naproxen carried the least vascular risk.
How to notice: Shortness of breath on effort, endurance falling for no training reason, palpitations.
Elevated
Dehydration, electrolyte loss, cramps
rareIn an Ironman study NSAID users more often had low blood sodium (exertional hyponatremia), a dangerous state in long events; they also raise potassium.
How to notice: Cramps, thirst, weakness, dizziness, dark urine; power and endurance fall, especially in the heat.
Moderate
Nausea, GI upset, pancreatitis risk
possibleHeartburn, stomach pain and ulcers are possible; ulcers can form without warning pain. In a marathon study, painkillers made stomach-related race withdrawals more common.
How to notice: Nausea, fullness, constipation or diarrhea; often worse in hard or long sessions.
Moderate
Higher blood pressure
possibleCan raise blood pressure and weaken BP drugs such as ACE inhibitors, sartans and diuretics; home readings show it.
How to notice: Often silent; sometimes headaches, flushing, nosebleeds — a home monitor shows it. Heavy lifts briefly spike it even in healthy lifters.
Moderate
Tendon / ligament injury risk
possiblePain relief lets training go on over an injury. Sports physicians avoid them for muscle tears, stress fractures and chronic tendon pain because healing may suffer.
How to notice: Pain at tendon attachments under heavy load; in steroid-using bodybuilders about a quarter of ruptures followed such pain.
Moderate
Liver strain
rareMainly diclofenac: liver-enzyme rises, mostly mild, in about 15% of users; severe liver injury is rare. Hard training also raises ALT and AST.
How to notice: Usually silent early; later tiredness, nausea, itch, dark urine.
Low
Water retention / bloating
possibleFluid retention and swelling (edema) are listed on the labels.
How to notice: Puffy face and ankles, softer look, quick weight jumps.
What the levels mean
Lowbackground — just be aware
Moderatewatch for signs
Elevatedneeds regular control
Highcritical — can be life-threatening or permanent
Level: general category from the literature, not your personal risk
How often
- common
- reported often
- possible
- reported in some people
- rare
- reported occasionally
How to lower the risks
For 9 of 9 possible side effects there are specific ways to lower the chance: everyday measures, supplements and options a doctor may consider. No measure removes a risk completely. Prescription medicines are listed only for a doctor to decide on, after tests — they have side effects of their own.
ElevatedBleeding risk (bruising, stomach or brain bleeds)
Do not combine blood-thinning products (aspirin, painkillers such as ibuprofen, high intakes of fish oil, nattokinase, vitamin E) without a doctor; warn doctors and dentists before procedures; alcohol adds to stomach-bleeding risk. On anticoagulants, contact sports are usually put on hold.
Measure
Supplement or OTC product
How each option helps (4)
- Working with a doctor — Checks which blood-thinning products are combined (aspirin, ibuprofen-type painkillers, fish oil, vitamin E) and whether stomach protection is needed; tell doctors and dentists before procedures.
- Avoiding alcohol and other liver stressors — Alcohol adds to stomach-bleeding risk with aspirin and painkillers such as ibuprofen; cutting it out lowers that part of the risk.
- Omeprazole and other proton-pump inhibitors (PPIs) — Lowered aspirin stomach ulcers, and upper-gut bleeding on aspirin plus clopidogrel, in trials; not bruising or brain bleeds. Who needs it is a doctor's call (age, past ulcer).
- Famotidine (H2 blockers) — Cut new ulcers in low-dose aspirin users in a trial, but bleeding itself was not the outcome studied; guidelines name PPIs for bleeding cover. A doctor decides.
ElevatedKidney strain
Drink enough, more in heat; control blood pressure; avoid regular painkillers (NSAIDs) and any during long or hot events; no weight cutting by dehydration.
Measure
Only if a doctor prescribes
How each option helps (8)
- Fluid & electrolyte management — Good hydration eases kidney stress from heavy training and heat; dehydration plus NSAIDs is a classic cause of acute kidney injury.
- Regular blood tests — Creatinine runs high with big muscle mass, creatine and hard training, and standard eGFR formulas mislead in athletes; compare with your own baseline and add cystatin C and urinalysis.
- Working with a doctor — Investigates protein in the urine or falling kidney function and can start treatment that slows kidney damage.
- Home blood-pressure monitoring — Catches high blood pressure early — a main driver of kidney damage on steroids; it helps only if high readings lead to treatment.
- ACE inhibitors (ramipril, perindopril, lisinopril) — Lower blood pressure (a key cause of kidney strain on steroids) and are standard care when urine shows protein; a doctor decides. With dehydration, diuretics or NSAIDs they can harm the kidneys. Has side effects of its own.
- Losartan / valsartan (angiotensin receptor blockers) — Lower blood pressure (a key cause of kidney strain on steroids) and are standard care when urine shows protein; a doctor decides. With dehydration, diuretics or NSAIDs they can harm the kidneys. Has side effects of its own.
- Telmisartan — Lowers blood pressure (a key cause of kidney strain on steroids) and is standard care when urine shows protein; a doctor decides. With dehydration, diuretics or NSAIDs it can harm the kidneys. Has side effects of its own.
- Amlodipine — Lowering blood pressure eases kidney strain, but unlike ARBs or ACE inhibitors it does not cut protein in the urine. Only on a doctor's prescription. Has side effects of its own.
ElevatedHeart strain / heart-muscle thickening
Regular cardio, blood pressure control, an echo as a baseline and then yearly, read by a cardiologist who knows athletes’ hearts.
Measure
Supplement or OTC product
Only if a doctor prescribes
How each option helps (12)
- Heart screening: ECG and echocardiogram — Echocardiography shows wall thickening and reduced pumping early, while stopping AAS and treating BP can still help.
- Working with a doctor — Orders ECG and echocardiography and treats early heart changes.
- Home blood-pressure monitoring — Keeping BP controlled is one of the main ways to limit heart-wall thickening.
- Regular cardio training — Supports heart and vessel function, but does not reverse steroid-related heart thickening or weakening.
- Coenzyme Q10 — One trial in heart failure found fewer major heart events, but it was small and guidelines do not recommend it; not studied in steroid users and not a heart treatment.
- ACE inhibitors (ramipril, perindopril, lisinopril) — Standard treatment for heart failure; shrink a thickened heart wall in hypertension. An echo helps tell athlete's heart from hypertensive or steroid thickening; the steroid risk remains. Has side effects of its own.
- Bisoprolol — In heart failure with weak pumping it lowered deaths in trials; doctors add it to standard therapy. Not studied in steroid users; the steroid risk to the heart remains. Has side effects of its own.
- Carvedilol — A doctor may add it when tests show weak heart pumping; in heart failure it lowered deaths. Not studied in steroid users, and it does not undo steroid damage. Has side effects of its own.
- Losartan / valsartan (angiotensin receptor blockers) — Shrink a thickened heart wall in hypertension at least as well as other BP drugs. An echo helps tell athlete's heart from hypertensive or steroid thickening; the steroid risk remains. Has side effects of its own.
- Nebivolol — In older adults with heart failure it lowered hospital stays and deaths combined; a doctor may add it when pumping is weak. Not studied in steroid users; the steroid risk to the heart remains. Has side effects of its own.
- Telmisartan — In high blood pressure, ARBs shrink a thickened heart wall at least as well as other BP drugs. Not studied in steroid users; the steroid risk to the heart remains. Has side effects of its own.
- Amlodipine — By lowering blood pressure it shrinks a thickened heart wall somewhat (trials in high BP); it is not a heart-failure drug. Not studied in steroid users. Has side effects of its own.
ElevatedDehydration, electrolyte loss, cramps
Drink to thirst, more in heat and long sessions, with sodium-containing drinks; far beyond thirst risks low sodium. No weight cutting by dehydration. With diuretics, ARBs/ACE inhibitors or kidney problems: potassium products or salt substitutes only after a blood test and a doctor’s advice.
Measure
Supplement or OTC product
How each option helps (18)
- Fluid & electrolyte management — Weighing before and after training shows sweat loss; ACSM advises keeping it under about 2% of body weight. Salty fluids help, but they do not offset the losses diuretics cause.
- Heat acclimatisation & cooling — Fluid and salt balance improves, but acclimatised athletes sweat more, so fluid needs go up, not down; it does not replace drinking or offset diuretic losses.
- Regular blood tests — Sodium, potassium, magnesium and kidney tests catch dangerous shifts from diuretics, clenbuterol or thyroid hormone; they do not make those drugs safe.
- Electrolytes (sodium, potassium, magnesium) — Replacing sweat sodium and fluid may lower the chance of dehydration and heat cramps; it does not remove heat-illness risk or make diuretics or water cuts safe, and its potassium is risky with ARBs.
- Magnesium — Replaces magnesium lost in sweat or with diuretics; there is no good evidence that it stops exercise cramps. It does not make diuretic use or extreme weight cutting safe.
- Magnesium aspartate — Replaces magnesium lost in heavy sweat or with diuretics. A Cochrane review found no trials of magnesium for exercise-associated cramps. Does not make diuretics safe.
- Magnesium carbonate — Supplies magnesium, but it is used mainly as an antacid and there are few data on it as a supplement; chalk on the hands supplies none. Does not make diuretics safe.
- Magnesium chloride — Replaces magnesium lost in heavy sweat or with diuretics. A Cochrane review found no trials of magnesium for exercise-associated cramps. Does not make diuretics safe.
- Magnesium citrate — Replaces magnesium lost in heavy sweat or with diuretics. A Cochrane review found no trials of magnesium for exercise-associated cramps. Does not make diuretics safe.
- Magnesium gluconate — Replaces magnesium lost in heavy sweat or with diuretics. Cochrane found no trials in exercise cramps; runners who cramped did not have lower blood magnesium. Does not make diuretics safe.
- Magnesium glycinate (bisglycinate) — Replaces magnesium lost in heavy sweat or with diuretics. A Cochrane review found no trials of magnesium for exercise-associated cramps. Does not make diuretics safe.
- Magnesium lactate — Replaces magnesium lost in heavy sweat or with diuretics. A Cochrane review found no trials of magnesium for exercise-associated cramps. Does not make diuretics safe.
- Magnesium malate — Replaces magnesium lost in heavy sweat or with diuretics. A Cochrane review found no trials of magnesium for exercise-associated cramps. Does not make diuretics safe.
- Magnesium orotate — Replaces magnesium lost in heavy sweat or with diuretics. A Cochrane review found no trials of magnesium for exercise-associated cramps. Does not make diuretics safe.
- Magnesium oxide — Supplies some magnesium, but far less is absorbed than from soluble salts; Cochrane found no trials in exercise cramps. Does not make diuretics safe.
- Magnesium taurate — Replaces magnesium lost in heavy sweat or with diuretics. A Cochrane review found no trials of magnesium for exercise-associated cramps. Does not make diuretics safe.
- Potassium — Replaces potassium lost with sweat or thiazide and loop diuretics when a test shows it is low; it does not make diuretics safe and is risky with potassium-sparing ones.
- Taurine — Used in practice against cramps on clenbuterol or diuretics; trials show fewer cramps only in liver disease, the clenbuterol link is rat data. Such cramps can mean low potassium: get a blood test.
ModerateNausea, GI upset, pancreatitis risk
Smaller meals, enough fluid and fiber, test race-day food in training first; a doctor for severe abdominal pain.
Measure
Supplement or OTC product
How each option helps (14)
- Avoiding alcohol and other liver stressors — Alcohol irritates the stomach, adds to aspirin-related stomach bleeding and is a main cause of pancreatitis; avoiding it lowers that part of the risk, not drug nausea.
- Fluid & electrolyte management — Dehydration makes gut complaints in long or hot sessions more likely; drinking enough helps that part, not nausea from drugs or pancreatitis.
- Working with a doctor — Assesses persistent vomiting or severe belly pain (possible pancreatitis or gallstones), can add stomach protection to aspirin and adjusts GLP-1 treatment when nausea persists.
- Omeprazole and other proton-pump inhibitors (PPIs) — A doctor may consider it for heartburn, reflux, dyspepsia or ulcer cover with aspirin or NSAIDs (label, guidelines). It does little for nausea or diarrhea; long-term use has its own risks.
- Famotidine (H2 blockers) — Relieves and prevents occasional heartburn (label); it does not help nausea or diarrhea. For reflux damage or long-term ulcer cover a doctor usually turns to a PPI.
- Loperamide — Eases acute diarrhea, including on GLP-1 drugs (consensus), but not its cause; not for nausea or bloody stools. Fluids and salts still come first.
- Macrogol (polyethylene glycol laxative) — Eases constipation, including on GLP-1 drugs, with strong guideline backing in chronic constipation; not for nausea or heartburn. Rectal bleeding or worsening pain needs a doctor.
- Magnesium carbonate — An antacid for heartburn and indigestion (label), often combined with other antacids; it does not help nausea and may itself loosen stools. Not with weak kidneys.
- Magnesium citrate — In larger amounts a saline laxative for occasional constipation (label); not for nausea. It causes cramps and loose stools itself; ask a doctor first with kidney disease.
- Magnesium hydroxide — Labeled as an antacid for heartburn and a laxative for occasional constipation; short-term relief only, not for nausea. It can itself cause diarrhea; not with weak kidneys.
- Magnesium oxide — An osmotic laxative that eases constipation (conditional guideline advice); not for nausea or heartburn. It loosens stools itself; with weak kidneys blood magnesium can rise.
- Pancreatin + dimeticone (Pankreoflat) — Registered for heaviness and bloating after meals; it does not ease drug nausea, heartburn or aspirin stomach pain. Not with pork or cow's milk protein allergy or acute pancreatitis.
- Probiotics — May ease diarrhea, for example on GLP-1 drugs (consensus); in sport studies they mostly did not reduce exercise gut symptoms. Not for nausea or heartburn.
- Psyllium husk fiber — Soluble fiber eases constipation, including on GLP-1 drugs, and can firm loose stools; it does not help nausea or heartburn and can itself cause bloating and gas.
ModerateHigher blood pressure
Less salt, regular cardio, good sleep, home readings; if it stays high — a doctor, and a talk about maximal lifts.
Measure
Supplement or OTC product
How each option helps (22)
- Home blood-pressure monitoring — Persistently high resting readings mean seeing a doctor. For athletes, guidance prefers ARBs or ACE inhibitors, which don't limit exercise capacity; diuretics are banned in sport.
- Regular cardio training — In a meta-analysis of trials, endurance training lowered resting BP by about 8/5 mmHg in people with high BP and only slightly in those with normal BP.
- Working with a doctor — Diagnoses persistent hypertension and prescribes treatment when needed.
- Avoiding alcohol and other liver stressors — Regular drinking raises blood pressure; cutting it out lowers it.
- Coenzyme Q10 — Inconsistent: some analyses show a small systolic drop in cardiometabolic disease, but a Cochrane review found no clinically meaningful effect.
- Dietary nitrate (beetroot juice) — In trials of people with high blood pressure, beetroot nitrate lowered systolic pressure by about 5 mmHg; diastolic barely changed. Not a substitute for a doctor’s treatment.
- Magnesium — Meta-analysis of 34 trials in adults, not athletes: about 2 mmHg lower systolic pressure on average.
- Magnesium aspartate — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium carbonate — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor’s assessment of high pressure found at a sports check.
- Magnesium chloride — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium citrate — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium gluconate — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium glycinate (bisglycinate) — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium L-threonate — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor’s assessment of high pressure found at a sports check.
- Magnesium lactate — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium malate — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium orotate — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium oxide — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium taurate — Meta-analysis of trials: about 2 mmHg lower systolic pressure on average — too small to replace a doctor's assessment of high pressure found at a sports check.
- Omega-3 (fish oil, EPA/DHA) — Small drop of a few mmHg, mainly in people with untreated high blood pressure.
- Potassium — Trials: about 3.5 mmHg lower systolic, only in people with high BP. Dangerous with spironolactone, ARBs/ACE inhibitors or weak kidneys — a blood test first, a doctor decides.
- Taurine — Meta-analysis of 20 small trials: about 4 mmHg lower systolic pressure on average.
ModerateTendon / ligament injury risk
Progress weights gradually — strength rises faster than tendons adapt; with persistent tendon pain, cut the load and see a sports physician.
Measure
Supplement or OTC product
How each option helps (3)
- Graded tendon loading with a physiotherapist — Treats tendon pain and rebuilds load tolerance; in a trial both heavy slow and eccentric loading gave lasting relief. No study shows it offsets the higher rupture risk on steroids.
- Working with a doctor — A quarter of tendon ruptures in steroid users followed local pain; a sports physician who sees that pain early can cut the load before a tear.
- Collagen peptides and gelatin — Gelatin with vitamin C raised a collagen-synthesis marker with exercise; whether this means fewer tendon injuries is unknown. Strength still rises faster than tendons adapt.
ModerateLiver strain
No alcohol or other liver stressors, limit oral steroids and their combinations; check liver enzymes (hard training raises ALT and AST too).
Measure
Supplement or OTC product
How each option helps (9)
- Avoiding alcohol and other liver stressors — Removes a major extra liver stressor during oral steroids and other hepatotoxic drugs.
- Regular blood tests — ALT, AST, GGT and bilirubin show liver strain early. Weightlifting raised AST, ALT and CK for at least a week in men new to it, while GGT stayed normal — it helps tell muscle from liver.
- Working with a doctor — Tells muscle from liver in raised enzymes, looks for other causes such as viral hepatitis, and advises stopping the oral steroid early — the step that matters most.
- Ademetionine (SAMe) — Used for intrahepatic cholestasis in some countries, but trials are small and of low quality; untested in steroid users. Stopping the oral steroid matters most.
- Essential phospholipids (Essentiale) — One non-randomised study in steroid users saw smaller liver-enzyme rises; other trials are small and at risk of bias. Used in practice; stopping the oral steroid matters most.
- Glutathione — The antioxidant the liver uses to clear toxins; untested in steroid liver injury, and NAC is the better-studied way to raise it. Drips outside hospital carry infection and kidney risks.
- Milk thistle (silymarin) — Widely taken for liver support on oral steroids, but trials in hepatitis and fatty liver found little or no benefit, and none tested steroid users. Stopping the oral steroid matters most.
- N-acetylcysteine (NAC) — Restores glutathione; standard for paracetamol poisoning and helped some other acute liver failure in hospital trials, but untested in steroid liver injury. Stopping the oral steroid matters most.
- TUDCA (tauroursodeoxycholic acid) — Improves bile flow in cholestatic disease; in steroid cholestasis only case reports, with failures in severe cases. Stopping the oral steroid matters most.
Low-level side effects
Water retention
Steady salt and water intake, cardio, check estradiol.
Measure
How each option helps (2)
- Regular blood tests — Estradiol, kidney, liver and protein tests help tell harmless retention from estrogen excess or organ trouble; testing alone lowers nothing.
- Working with a doctor — Tells harmless water retention from swelling due to heart, kidney or liver trouble; steroid labels warn that edema can come with heart failure.
Check-ups and blood tests
Which tests and check-ups to do and when. This is a guide — agree the exact schedule with a sports physician.
Baseline tests
your own starting values — every later result is compared with them
Liver panel (ALT, AST, GGT, bilirubin)Unaccustomed heavy weight training raised ALT and AST (from muscle) for at least a week, while GGT and bilirubin stayed normal — test after a break from hard training.liver
Complete blood count (hematocrit, hemoglobin)Endurance training dilutes the blood (“sports anemia”), dehydration concentrates it — test hydrated and rested, against your own baseline.bleeding
Kidney panel (creatinine, eGFR, cystatin C)Creatinine reads higher with big muscle mass or creatine; cystatin C barely depends on muscle and helps judge the kidneys in athletes.kidneys, electrolytes, blood pressure
Electrolytes (potassium, sodium, magnesium)Low sodium after long events mostly comes from drinking far beyond thirst; heavy sweating in the heat also costs sodium.electrolytes
Home blood-pressure logMeasure seated and rested, not within 30 minutes after training, caffeine or smoking — they change the reading.heart, kidneys, blood pressure
ECGTraining changes the ECG in ways that are normal for athletes; ask for a reading by the international athlete criteria, which separate these from disease.heart
Echocardiogram (heart ultrasound)Weight training alone does not weaken the heart’s pumping or relaxation; in a lifter that is not “athlete’s heart” — in steroid users it was linked to the drugs.heart
UrinalysisHard exercise can briefly put protein and blood into the urine, usually gone within a few days — test after rest and repeat before drawing conclusions.kidneys
While taking
about 4–6 weeks in, then every 6–8 weeks — agree the exact schedule with your doctor
Liver panel (ALT, AST, GGT, bilirubin)Unaccustomed heavy weight training raised ALT and AST (from muscle) for at least a week, while GGT and bilirubin stayed normal — test after a break from hard training.liver
Complete blood count (hematocrit, hemoglobin)Endurance training dilutes the blood (“sports anemia”), dehydration concentrates it — test hydrated and rested, against your own baseline.bleeding
Kidney panel (creatinine, eGFR, cystatin C)Creatinine reads higher with big muscle mass or creatine; cystatin C barely depends on muscle and helps judge the kidneys in athletes.kidneys, electrolytes, blood pressure
Electrolytes (potassium, sodium, magnesium)Low sodium after long events mostly comes from drinking far beyond thirst; heavy sweating in the heat also costs sodium.electrolytes
Home blood-pressure logMeasure seated and rested, not within 30 minutes after training, caffeine or smoking — they change the reading.heart, kidneys, blood pressure
UrinalysisHard exercise can briefly put protein and blood into the urine, usually gone within a few days — test after rest and repeat before drawing conclusions.kidneys
After stopping
4–8 weeks after stopping (later after long-acting injections), then until values return to baseline
Liver panel (ALT, AST, GGT, bilirubin)Unaccustomed heavy weight training raised ALT and AST (from muscle) for at least a week, while GGT and bilirubin stayed normal — test after a break from hard training.liver
Complete blood count (hematocrit, hemoglobin)Endurance training dilutes the blood (“sports anemia”), dehydration concentrates it — test hydrated and rested, against your own baseline.bleeding
Kidney panel (creatinine, eGFR, cystatin C)Creatinine reads higher with big muscle mass or creatine; cystatin C barely depends on muscle and helps judge the kidneys in athletes.kidneys, electrolytes, blood pressure
Every year
with regular or repeated use
ECGTraining changes the ECG in ways that are normal for athletes; ask for a reading by the international athlete criteria, which separate these from disease.heart
Echocardiogram (heart ultrasound)Weight training alone does not weaken the heart’s pumping or relaxation; in a lifter that is not “athlete’s heart” — in steroid users it was linked to the drugs.heart
Which doctors can help
Cardiologistheart, blood pressure
Gastroenterologist / hepatologistliver, digestion
Nephrologistkidneys
Sports physiciantendons
At home
- Home blood pressure: 2–3 times a week in the morning, keep a log
Get medical help at once if
- Black or bloody stools, vomiting blood or “coffee grounds”, bleeding that won’t stop, a sudden severe headache, any head blow on blood thinners (not aspirin alone) — urgent care or your local emergency number.
- Chest pain or pressure, fainting or near-fainting on exertion, breathlessness on light effort, swollen ankles — stop training and seek urgent care; collapse — call your local emergency number.
- Much less urine than usual, cola-colored urine (especially with severe muscle pain after hard training), new swelling, flank pain — see a doctor now.
- Severe cramps, marked weakness, palpitations, dizziness on standing, very little urine — seek urgent care. Vomiting, confusion or a seizure after a long event can mean low sodium — do not drink more, call your local emergency number.
- Sudden severe headache, vision changes, numbness or weakness on one side, trouble speaking — call your local emergency number.
- Yellow skin or eyes, dark urine, pale stools, intense itching, pain under the right ribs — see a doctor now; sudden severe abdominal pain with dizziness or fainting — call your local emergency number.
- A snap and sudden sharp pain in a tendon, inability to load the limb — stop training and get it examined.
- Severe upper-abdominal pain spreading to the back, with vomiting (urgent amylase/lipase test); pain under the right ribs with fever or yellow eyes; vomiting with no stool or wind; blood in stool after a long race — seek urgent care.
In an emergency, call your local emergency number.
For women
From about 20 weeks of pregnancy avoid them unless a doctor directs it: kidney problems in the unborn child and low amniotic fluid are possible; from about 30 weeks also a heart risk for the baby. They can cause reversible infertility.
Myth & fact
Myth
“Taking ibuprofen before a race or a heavy session keeps pain away and helps you perform.”
Fact
There is no evidence for taking it in advance. In an ultramarathon trial more runners on ibuprofen developed acute kidney injury; in a marathon survey, runners who took painkillers before the race reported hospital stays for kidney failure, bleeding and heart attacks.
Combinations
CautionNSAID painkiller with aspirin
Both harm the stomach lining and slow clotting, so together stomach bleeds become more likely; labels advise against combining them for pain. Ibuprofen and similar painkillers can also block the heart effect of low-dose aspirin (FDA). Black stools or vomiting blood need urgent care.
Aspirin (acetylsalicylic acid)CautionNSAID painkiller with a glucocorticoid
NSAID labels list glucocorticoids taken by mouth as a risk factor for stomach ulcers and bleeding, so together the chance rises. Ulcers can form without warning pain; black stools, vomiting blood or sudden belly pain need urgent care.
Prednisolone (incl. prednisone)MethylprednisoloneDexamethasoneDangerous combinationNSAID with a sartan or ACE inhibitor and a diuretic
Each of the three lowers kidney filtering in its own way. In a study of nearly half a million patients this trio raised acute kidney injury by about 30%, and by about 80% at the start of use. Dehydration, heat or water cutting make it more likely; a creatinine test shows it.
CautionNSAID with a sartan or ACE inhibitor
NSAIDs can weaken the effect of sartans and ACE inhibitors, so blood pressure may creep up. With dehydration, heat or water cutting the pair can reduce kidney function, sometimes to acute kidney failure, and potassium may rise.
CautionNSAID with a diuretic
NSAIDs blunt the water-removing effect of loop and thiazide diuretics, and when a diuretic has drained fluid they cut kidney blood flow further. NSAIDs also raise potassium, which adds to spironolactone. Creatinine and potassium tests show the effect.
CautionNSAID tablets together with an NSAID gel
A gel adds a little more NSAID to what the tablets already put in the blood. Gel labels say the pair has not been properly evaluated and may increase NSAID side effects, including bleeding and abnormal kidney tests; a doctor decides whether both are needed.
NSAID gels and patches (diclofenac, ibuprofen, ketoprofen)CautionNattokinase with aspirin or an NSAID painkiller
Nattokinase breaks down fibrin, while aspirin and NSAID painkillers make platelets less sticky. A bleed in the brain was reported in a woman who added nattokinase to aspirin. Unusual bruising, black stools or a sudden severe headache need urgent care.
NattokinaseAspirin (acetylsalicylic acid)Sources
Coxib and traditional NSAID Trialists' Collaboration, Lancet 2013: vascular and upper GI effects of NSAIDs (meta-analysis of 754 trials) (opens in a new tab)Cambia (diclofenac potassium) US Prescribing Information, FDA 2024: class warnings for NSAIDs (opens in a new tab)Lipman et al., Emerg Med J 2017: ibuprofen vs placebo and acute kidney injury in ultramarathons (RCT) (opens in a new tab)Wharam et al., Med Sci Sports Exerc 2006: NSAID use increases the risk of hyponatremia during an Ironman triathlon (opens in a new tab)Küster et al., BMJ Open 2013: analgesics before a marathon and cardiovascular, GI and renal problems (opens in a new tab)Lilja et al., Acta Physiol 2018: high-dose ibuprofen blunts muscle growth and strength gains from resistance training (opens in a new tab)Ziltener et al., Ann Phys Rehabil Med 2010: NSAIDs for athletes — not for muscle injuries, stress fractures or chronic tendinopathy (opens in a new tab)Warden, Phys Sportsmed 2010: prophylactic use of NSAIDs by athletes — a risk/benefit assessment (opens in a new tab)
Check how NSAID tablets (ibuprofen, naproxen, diclofenac and others) combines with your stack
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