Exercise and Kidney Health: A Coach's Guide to Understanding Kidney Function, Exercise Safety, and How Kidney Patients Should Train

First, a Case I’ll Never Forget

In over a decade of coaching, one case stands out. A male student in his early forties—let’s call him A-Jhe—was a regular cyclist. That summer, he signed up for a mountain race in central Taiwan. A month before the race, he suddenly ramped up his training, riding over 120 km on each of two consecutive weekend days, and deliberately drinking little water in between to “build mental toughness.” On the second day, he got home and noticed his urine output had dropped and the color was as dark as strong tea. His whole body ached so badly he couldn’t get out of bed, and his calves were hard as rocks. His wife knew something was wrong and dragged him to the emergency room. Blood tests showed creatine kinase (CK, an enzyme released into the blood when muscles are damaged) had skyrocketed to dozens of times the upper limit of normal, and his kidney function markers had deteriorated—a textbook case of exercise-induced rhabdomyolysis complicated by acute kidney injury.

Fortunately, he got to the hospital in time. Massive IV fluid resuscitation “flushed” his kidneys back to work, and after a few days in the hospital, he was discharged without needing dialysis. But this incident shook me: a seemingly healthy middle-aged man who exercised regularly nearly lost his kidneys, simply because three things came together—“too much intensity, too little water, and too much heat.”

The kidneys are silent organs. Unlike a pulled muscle, they don’t hurt right away. Many people have no idea that exercise can harm the kidneys. Some people with kidney disease are so afraid of exercise that they stop moving altogether—only to see their cardiovascular risk, sarcopenia, and quality of life all deteriorate, making things worse. In this article, I want to explain “exercise and the kidneys” from a coach’s perspective, from the ground up: Is exercise actually good or bad for the kidneys? Can people with kidney disease exercise, and if so, how can they do it safely? And what kidney-damaging landmines should everyone avoid?

Let me put the most important message up front: For the vast majority of people, regular, moderate exercise protects the kidneys. What truly damages them are extreme situations—sudden overtraining, severe dehydration, pushing through in high heat, combined with certain medications or supplements. I’ll break this down step by step below.

---

The Basics: What the Kidneys Do, and How Exercise Affects Them

The Role of the Kidneys

Let’s build the concept in plain language. Your kidneys are like two “water purification and regulation plants” located in your lower back. Their main jobs include:

• Filtering waste: Removing metabolic waste products like urea and creatinine, excreting them as urine.
• Regulating water and electrolytes: Balancing ions like sodium, potassium, calcium, and phosphorus, as well as total body water.
• Maintaining blood pressure: Through fluid regulation and hormonal systems.
• Endocrine function: Secreting erythropoietin (which helps produce red blood cells) and activating vitamin D (for bone health).

The most common measure of kidney function is eGFR (estimated glomerular filtration rate), expressed in mL/min/1.73m². The higher the number, the better the kidneys are filtering. Clinically, chronic kidney disease (CKD) is staged from 1 to 5 based on eGFR; the higher the stage, the worse the kidney function. We’ll refer back to this staging when discussing exercise safety later.

What Happens to the Kidneys During Exercise

When you exercise, your body prioritizes blood flow to the working muscles and skin (for cooling), so blood flow to the kidneys temporarily decreases. This is a normal physiological response that reverses once you stop. For healthy kidneys, this brief redistribution of blood flow is no problem.

But things get complicated if several of the following happen at once:

1. Severe dehydration: Blood becomes more concentrated, kidney blood flow drops further, and filtration pressure rises.
2. Extensive muscle damage (rhabdomyolysis): Damaged muscle cells release myoglobin. When large amounts enter the bloodstream, it can clog the kidney tubules and directly poison the kidneys.
3. High ambient temperature: Worsens dehydration and strains thermoregulation.

When these three combine, you get the situation A-Jhe was in at the start. Research literature indicates that while exercise-induced rhabdomyolysis is not common overall, when it does occur, approximately 10% to 30% of cases progress to acute kidney injury, which significantly raises the risk of subsequent complications. This is absolutely not something to take lightly (see references at the end).

What About Long-Term Regular Exercise? Protective or Harmful?

This is where many people get confused. A single bout of extreme exercise can harm the kidneys, but long-term, regular moderate-intensity exercise is, based on the evidence, protective for the kidneys.

Regular exercise improves blood pressure, blood sugar, body weight, and blood lipids—and high blood pressure and diabetes are the two biggest drivers of chronic kidney disease in Taiwan. In other words, exercise protects the kidneys indirectly by “managing blood pressure and blood sugar.” For people who already have CKD, multiple international guidelines and consensus statements consistently encourage them to be regularly active within their capabilities, because exercise improves fitness, strength, balance, and quality of life, and may even confer cardiovascular and survival benefits (see references at the end).

As for whether “exercise can improve your eGFR number,” the evidence is more conservative: some studies have seen small increases in eGFR in stage 3 and 4 CKD patients with aerobic exercise, but the effect is small and study quality varies. So exercise should not be viewed as a “treatment” for the kidneys. The value of exercise lies in overall health and function, not in chasing a lab number. I want you to keep that balance in mind.

Why Dehydration Is So Lethal to the Kidneys

I often use this analogy with my students: the kidneys filter blood, and they need “enough blood flow” to do it. Think of them as a water filtration system that needs stable water pressure—if the pressure is adequate, the filter works properly. When you’re dehydrated, your blood becomes thicker and blood volume drops, so flow through the kidneys becomes insufficient. The environment inside the kidney tubules becomes more acidic and concentrated, and if a flood of myoglobin arrives at that point, it’s especially prone to “clumping and clogging” the tubules, causing obstruction and toxic damage.

This is why the literature repeatedly emphasizes: adequate hydration before, during, and after exercise is the single most critical step in preventing exercise-related acute kidney injury. Early, generous fluid resuscitation is often the dividing line between whether a patient needs dialysis or not. The preventive version you can do at home is simply not pushing yourself through severe dehydration in the heat.

Electrolytes: It’s Not Just About Drinking Water

Many people think “just drink more water.” But for prolonged exercise with heavy sweating, drinking only plain water can actually cause problems—this is called exercise-associated hyponatremia. Sweat doesn’t just remove water; it also removes electrolytes like sodium. If you replace only water without sodium, the sodium in your blood gets diluted, which in severe cases can cause headache, nausea, confusion, and even be life-threatening. So for exercise lasting more than roughly 60 to 90 minutes, I recommend including an electrolyte sports drink or supplements. The table below helps you figure out “what to replenish”:

Exercise Duration	Primary Replenishment	Why
Under 30 minutes	Plain water is sufficient	Losses are limited; daily diet is enough to replace electrolytes
30–60 minutes	Plain water primarily	In high heat with heavy sweating, a small amount of electrolytes may be considered
Over 60–90 minutes	Water + electrolytes (containing sodium)	Avoid hyponatremia from drinking only plain water
Long distance in hot, humid conditions	Electrolyte drink + moderate carbohydrates	Addresses hydration, sodium, and energy simultaneously

---

Practical Approach (Part 1): How Healthy People Can Exercise Without Hurting Their Kidneys

This section is for people without kidney disease who want to exercise with peace of mind. The core message is one sentence: Don’t let “overtraining + dehydration + high heat” happen at the same time.

Hydration Strategy: The Key Task for Taiwan Summers

Taiwan summers are humid and hot. A midday long ride or run along the riverside can produce a massive amount of sweat. Poor hydration is asking for kidney trouble. The table below is the general hydration reference I give my students. Remember, these are general principles—adjust based on your body weight, sweat rate, and weather:

Timing	Reference Hydration Amount	Coach’s Note
2 hours before exercise	About 400–600 mL	“Fill the reservoir” first; don’t head out dehydrated on an empty stomach
15 minutes before exercise	About 150–250 mL	Sip it; don’t chug and feel bloated
During exercise (every 15–20 minutes)	About 150–250 mL	Take the upper end in high heat or heavy sweating
Exercise over 60–90 minutes	Electrolyte sports drink	Plain water alone may dilute blood sodium; long sessions need sodium
After exercise	Replace based on body weight change	Weigh yourself before and after; replace about 1–1.5 L per kg lost

One extremely practical self-check: look at the color of your urine. Light yellow urine after exercise (like diluted lemonade) means you’re roughly well-hydrated. Dark yellow, or even the color of strong tea or black tea, is a clear warning sign of dehydration—especially if it’s as dark as “soy sauce or cola” and accompanied by severe muscle pain, which could be myoglobinuria and requires immediate medical attention.

Training Volume: Progress Gradually, Don’t Skip Levels

A-Jhe’s mistake was “overtraining before a race.” Your body needs time to adapt to training load. Suddenly spiking weekly mileage or intensity, before the muscles are ready, raises the risk of rhabdomyolysis. The principle I commonly use is increasing weekly training volume by no more than about 10%, letting the body catch up gradually. Below is a four-week progressive example for a generally healthy adult who’s been sedentary and wants to restart (using cycling as an example, at an easy-to-moderate intensity where you can speak normally):

Week	Duration per Session	Sessions per Week	Perceived Intensity	Focus
Week 1	20–30 minutes	3	Can chat easily	Build the habit; don’t chase speed
Week 2	30–40 minutes	3	Slightly breathless but can talk	Add a little time
Week 3	40–50 minutes	3–4	Moderate, some sweating	Can add a short gentle climb
Week 4	50–60 minutes	3–4	Moderate	Start feeling like a “regular exerciser”

Remember, warm-up and cool-down are not optional. A proper warm-up gets muscles and circulation ready and reduces the chance of muscle damage; cool-down and stretching aid recovery. These are also listed in the literature as important strategies for preventing exercise-induced rhabdomyolysis. I usually have my students spend 5 to 10 minutes of easy pedaling or brisk walking before the main session to gradually raise heart rate, body temperature, and muscle temperature—especially if they haven’t exercised in a while, or are about to do unfamiliar high-intensity movements (like a first spin class or first heavy squat session). This “warming up” step dramatically reduces the chance of excessive muscle damage.

Another detail that’s often overlooked: unfamiliar exercises and movements with lots of eccentric contractions are especially prone to causing muscle damage. For example, someone who hasn’t run in a long time suddenly running downhill, or someone who hasn’t lifted weights in a while suddenly doing heavy resistance work. Muscles are most vulnerable when they contract while being lengthened (eccentric contraction). So when you try a new sport or a new program, be conservative the first time. Give your body a few days to adapt—don’t go all out on day one.

Supplements and Medications: The Often-Overlooked Kidney Landmines

I want to call special attention to this section, because too many people get burned here:

• Painkillers (NSAIDs): Non-steroidal anti-inflammatory drugs like ibuprofen, when taken while dehydrated or during intense exercise, further reduce kidney blood flow. Many people pop painkillers for post-exercise muscle soreness, and combined with sweat-induced dehydration, it’s a double blow to the kidneys. If you’re dehydrated on a training day, don’t casually take these painkillers. Consult a doctor or pharmacist first if needed.
• Supplements, muscle-building powders, or fat-loss products of unknown origin: Ingredients are opaque, and some are contaminated with diuretics or kidney-damaging substances.
• Excessive protein: Most exercisers get enough protein from a balanced diet. Deliberately chugging large amounts of protein powder is usually harmless for healthy kidneys, but if you already have kidney function problems, protein intake absolutely must be discussed with your doctor and dietitian—don’t self-prescribe.

---

Practical Approach (Part 2): How Kidney Patients Can Exercise Safely

This is what many kidney patients and their families care about most: “My doctor says my kidneys aren’t great—can I still exercise?” My answer is—in most cases, not only can you, but you’re encouraged to. However, it must be individualized and discussed with your nephrologist first.

Let’s establish a key premise: Kidney disease varies enormously. A person whose eGFR just dropped to stage 3 but is otherwise stable is a completely different situation from someone on dialysis with heart problems. Their exercise prescriptions are worlds apart. So the content below is educational general guidance, not a substitute for your healthcare team’s individualized advice. Before starting any new exercise program, every kidney patient must consult their nephrologist, and if necessary, be referred for rehabilitation or exercise physiology assessment.

Exercise Considerations by CKD Stage

The table below summarizes “considerations” to help you frame discussions with your doctor. Actual intensity and frequency must be individualized:

CKD Stage (by eGFR)	Exercise Feasibility	General Direction	Special Considerations
Stage 1–2 (kidney function still good)	Usually can exercise like the general population	Regular aerobic + strength training; manage blood pressure and blood sugar	Controlling the underlying disease (diabetes, hypertension) is most important
Stage 3	Most can exercise regularly	Moderate-intensity aerobic primarily, plus light resistance training	Pay attention to hydration and electrolytes; avoid overtraining
Stage 4	Activity still encouraged, but intensity should be conservative	Low-to-moderate intensity, longer sessions broken into segments	Work closely with your doctor; watch blood pressure and fatigue
Stage 5 / on dialysis	Can exercise, often during dialysis or on non-dialysis days	Requires design by the medical team; focus on maintaining strength and function	Electrolytes (especially blood potassium), blood pressure, and anemia all need consideration

Three Key Principles for Kidney Patients Exercising

From my experience, kidney patients who follow three principles stay much safer:

1. Start at low intensity and short duration; err on the side of caution. For example, start with just 10–15 minutes of walking, split into two or three sessions a day, and gradually increase once adapted. Kidney patients often have concurrent anemia, sarcopenia, and cardiovascular issues, so their baseline fitness is weaker. Haste makes waste.
2. Prioritize resistance training (strength training). Kidney disease patients are highly prone to muscle loss (sarcopenia), which directly affects mobility, metabolism, and survival. Gentle strength training with light dumbbells, resistance bands, or body weight is especially valuable for kidney patients. International guidelines also emphasize the importance of resistance training in the CKD population.
3. Monitor body signals; don’t push through. Learn to control intensity with the “talk test”: if you can still speak in short sentences during exercise, that’s moderate intensity. If you’re too breathless to talk, you’re going too hard. If you experience chest tightness, dizziness, unusual breathlessness, or a noticeable worsening of lower limb swelling, stop immediately and seek medical attention.

A Gentle Starting Example for a Stage 3 Kidney Patient

This is the introductory direction I often give to stage 3 kidney patients who are stable and have received medical clearance to exercise (this is illustrative only—please individualize):

• Aerobic: Brisk walking or a stationary bike, 15–30 minutes per session, 3–5 times per week, at an intensity where you’re “slightly breathless but can still talk.”
• Strength: Resistance bands or light dumbbells, targeting large muscle groups like thighs, glutes, and back. Each exercise 10–15 reps, 1–2 sets, twice a week, with a rest day in between.
• Flexibility/Balance: A few minutes of stretching daily. For older kidney patients, add balance and functional movements like single-leg stands or sit-to-stand to reduce fall risk.

For those on dialysis, “intradialytic exercise” is common—low-intensity pedaling on a stationary bike during the first half of a hemodialysis session. This requires arrangement and monitoring by the dialysis unit and medical team; it’s not something you just do on your own.

Another Case: A Stage 3 Kidney Patient Afraid to Move, and How She Got Back to Exercise

Let me share a case that’s the complete opposite of A-Jhe’s. A woman in her sixties—let’s call her Auntie Xiu-Qin—had diabetes for many years, and her kidney function had dropped to stage 3. The moment she heard “your kidneys aren’t good,” she was terrified and basically sat still all day, afraid that any exercise would “wear out” her kidneys. Six months later, she had gained weight, her blood sugar was harder to control, and the muscles in her thighs had visibly atrophied. Even getting up from the sofa or climbing stairs had become a struggle.

After evaluation, her nephrologist determined she was suitable for gentle exercise and referred her to me for help with planning. The first thing we did wasn’t “increase intensity”—it was dismantling her fear. I started her with a 10-minute walk around the community courtyard after meals, plus simple exercises with a resistance band: seated leg raises and sit-to-stand. The first two weeks she walked cautiously. By the third week, she started saying, “I want to walk one more lap today.” Three months later, she could brisk-walk for 30 minutes continuously, climb stairs without getting winded, her blood sugar had stabilized considerably, and her kidney function tracking remained stable.

Auntie Xiu-Qin’s story is meant to tell you one thing: for kidney patients, the harm of “not moving at all” is often greater than the risk of “gentle exercise.” The key is always to confirm with your doctor first, then start at the most conservative intensity. Exercise is not the enemy of kidney patients—a sedentary lifestyle is.

Warning Signs to Stop Exercising Immediately

Whether you’re healthy or a kidney patient, if your body sends these signals during exercise, it’s an alarm telling you to “stop, and seek medical attention if necessary.” I’ve made it into a table—I suggest you screenshot it and save it:

Warning Sign	What It May Indicate	What to Do Right Now
Urine turns the color of strong tea / cola / soy sauce	Myoglobinuria, rhabdomyolysis	Stop exercising immediately; seek medical attention as soon as possible
Severe muscle pain throughout the body, swelling and stiffness	Severe muscle damage	Stop and hydrate; seek medical attention if symptoms are pronounced
Urine output noticeably decreased, almost unable to urinate	Sign of acute kidney injury	Seek medical attention as soon as possible
Chest tightness, chest pain, unusual breathlessness	Cardiovascular risk	Stop immediately; call an ambulance if necessary
Dizziness, nausea, confusion	Heatstroke or hyponatremia	Move to shade, replenish electrolytes, seek medical attention if necessary
Sudden worsening of lower limb swelling	Change in kidney or heart status	Stop and return to your doctor as soon as possible

---

Common Mistakes and Corrections

After coaching for so many years, I’ve compiled the most common—and most dangerous—mistakes into a comparison table. Check whether any of these apply to you:

Common Mistake	Why It’s Dangerous	Coach’s Suggested Correction
Crazy overtraining in the week before a race	Muscles can’t adapt in time; risk of rhabdomyolysis skyrockets	Progress gradually over weeks; actually reduce volume the week before the race (taper)
Deliberately not drinking water to “build mental toughness”	Dehydration directly harms the kidneys and can cause heatstroke	Hydrate at regular intervals; replenish electrolytes for long sessions
Pushing hard along the riverside at the hottest time of day	High heat worsens dehydration and thermoregulatory strain	Switch to early morning or evening; avoid the 11 AM–3 PM heat
Taking painkillers on your own for post-exercise soreness	NSAIDs plus dehydration doubly reduce kidney blood flow	Hydrate and rest first; consult a doctor or pharmacist before taking medication
Being afraid to move at all because of kidney disease	Sarcopenia, cardiovascular risk, and quality of life all decline	After discussing with your doctor, start regular low-intensity exercise
Taking unverified muscle-building / fat-loss supplements	Ingredients unknown; may contain kidney-damaging substances	Get nutrients from a balanced diet; consult a professional before taking supplements
Continuing to exercise with tea-colored urine	Could be myoglobinuria; your kidneys are being injured	Stop immediately and seek medical attention as soon as possible

I especially want to emphasize the combination of “tea-colored urine + severe generalized muscle soreness + decreased urine output.” When these three appear together, it’s a red alert for rhabdomyolysis with kidney injury. Don’t tough it out, don’t wait and see—go straight to the emergency room. Taiwan has convenient medical access and high healthcare availability. Early treatment in the ER with aggressive IV fluids is often the key to avoiding dialysis. Many cases in the literature recovered without needing further dialysis precisely because of early, adequate fluid resuscitation.

Actionable Advice for Different Reader Groups

Finally, I’ve organized recommendations by group. Find where you fit.

For Complete Beginners / Sedentary People

• First, aim to “get moving,” not to go fast. Use the four-week progressive table above as your starting point.
• Build the habit of weighing yourself before and after exercise, and checking urine color afterward. These two free tools can help you monitor dehydration.
• In Taiwan summers, avoid midday heat. Make good use of early morning riverside paths, evenings, or air-conditioned gyms.
• If you have a chronic condition (hypertension, diabetes, heart disease, kidney disease), get a health check-up and talk to your doctor before starting exercise.

For People with Exercise Habits Who Want to Challenge Longer Distances

• Tapering before a race is more important than overtraining. Understand that your body isn’t built in the week before a race—it’s built over the preceding months.
• For long-distance events, plan hydration and sodium stations in advance. Don’t head out with only plain water.
• When the forecast calls for high heat and humidity, proactively lower your target pace or shorten the distance. Don’t fight your body.
• Learn to recognize the early signs of rhabdomyolysis, and know when to drop out of a race or seek medical attention.

For Kidney Patients and Their Families

• The first step is always: discuss your exercise plan with your nephrologist. Treat this article as a starting point for discussion, not a substitute.
• Don’t stop moving out of fear—the sarcopenia, cardiovascular decline, and loss of quality of life from inactivity are often worse than the risks of gentle exercise.
• Start with low-barrier activities like walking or resistance bands. Put “regularity” ahead of “intensity.”
• If you’re on dialysis, ask your dialysis unit whether they offer “intradialytic exercise.”
• Always take abnormal body signals seriously (worsening swelling, unusual breathlessness, chest tightness, dizziness) and return to your doctor early.

A Practical “Should I Push Harder Today?” Self-Check

Thirty seconds before exercise, ask yourself these questions. If you answer “yes” to any of them, be conservative that day:

• Is it over 32°C today, with high humidity?
• Have I been sleep-deprived or feeling very fatigued lately?
• Have I been drinking noticeably less water today?
• Is my training volume this week already much higher than last week?
• Have I recently had a cold, fever, or am I taking certain medications?

This checklist looks simple, but it blocks exactly the factors—“overtraining + dehydration + high heat + poor body condition”—that stack up to create kidney injury risk.

---

Taiwan Context: Practical Reminders for Eating Out and the Healthcare System

Living in Taiwan, there are a few local realities I want to highlight because they directly affect your kidneys.

The Hidden Burden of Eating Out and Heavy Salt

Eating out in Taiwan is incredibly convenient, but it’s also very salty. Braised snacks, fried chicken, hot pot broth, processed meats, and all kinds of sauces are high in sodium. A high-sodium diet drives up blood pressure, and high blood pressure is a major contributor to kidney damage. For athletes, there’s a balance to strike here: people who sweat heavily during exercise do need sodium, but that’s for replenishment “during exercise.” If your daily meals are chronically salty, it’s still a burden on your blood pressure and kidneys. My advice: replenish electrolytes properly during exercise, but keep everyday meals light—less soup, less sauce. Save the “sodium replenishment” for the exercise scenarios that truly need it.

The table below helps you separate the logic of hydration and sodium for “daily life” versus “during exercise.” Many people confuse these two:

Scenario	Hydration/Sodium Logic	Common Misconception
Daily life, no exercise	Drink water in moderation; eat light, low-salt meals	Thinking “drinking more sports drinks is healthier”—actually excess sugar and salt
Short exercise session	Plain water primarily	Chugging sports drinks for a short workout—unnecessary sugar
Long, heavy-sweating exercise	Water + electrolytes together	Drinking only plain water, leading to hyponatremia
Post-exercise recovery	Replace fluids based on losses	Both chugging everything at once and not drinking at all are bad

Making Good Use of the Healthcare System and Regular Check-ups

Taiwan has convenient medical access and high healthcare availability. This is actually a major advantage for protecting your kidneys. A few practical tips:

• Get regular blood tests to track kidney function: Especially if you have diabetes, hypertension, a family history of kidney disease, or take painkillers long-term. Regularly check eGFR and urine protein. Early detection means early treatment. You can proactively discuss this with your doctor during adult health check-ups or chronic disease follow-ups.
• Seek medical attention nearby when symptoms appear: If you experience the red-flag signs described earlier after exercise, emergency rooms in Taiwan are relatively easy to reach. Don’t delay because you “don’t want to be a bother.” Rhabdomyolysis with kidney injury is a race against time.
• Ask a professional before taking medication: Pharmacies and clinics are everywhere. Before taking painkillers, cold medicine, or unverified health supplements, ask a doctor or pharmacist about the effects on your kidneys. Don’t play doctor with yourself.

---

FAQ

Over the years of coaching, these are the questions I get asked most often about exercise and the kidneys. Here they are, all in one place.

Q1: I have “protein in my urine” after exercise. Does that mean my kidneys are damaged?

Not necessarily. A small amount of protein or occult blood in the urine shortly after intense exercise is often a normal physiological phenomenon and usually resolves with rest. What you really need to worry about is protein that appears “persistently and repeatedly.” If you have protein in your urine on multiple tests when you’re not exercising, then you should seriously see a nephrologist for evaluation. Don’t scare yourself, and don’t ignore it either.

Q2: Will a high-protein diet or whey protein damage my kidneys?

For people with normal kidney function, there’s currently no reliable evidence that a “reasonable high-protein diet” will damage healthy kidneys. But the key words are “reasonable” and “normal kidney function.” If you already have kidney disease, protein intake is an important item that needs individualized discussion with your doctor and dietitian—don’t chug whey on your own. Also, unverified muscle-building supplements with unclear labeling are the real landmines to watch out for.

Q3: How much water should I drink per day to protect my kidneys?

There’s no magic number that works for everyone. It depends on your body size, activity level, weather, sweat rate, and your own health status. For generally healthy adults, using “light yellow urine and no thirst” as your indicator is more practical than memorizing a number. But note: people with heart failure, certain advanced kidney diseases, or edema actually need to restrict fluids. In those cases, you must follow your doctor’s advice and not blindly drink more.

Q4: Can people with kidney stones exercise? What should they pay attention to regarding hydration?

Usually yes, and adequate hydration can actually help prevent certain types of kidney stones. If you sweat heavily during exercise and don’t replenish fluids, your urine becomes concentrated, which is theoretically unfavorable for stones. In practice, just hydrate well and keep your urine color light. But kidney stones have many causes and types. For dietary adjustments (for example, some people need to watch specific foods), please confirm with your urologist or nephrologist.

Q5: I have high blood pressure and take medication. Is exercise dangerous for me?

For well-controlled hypertension, regular exercise is actually a helper—it can lower blood pressure and protect the heart and kidneys. But there are a few prerequisites: first, have your doctor confirm that your blood pressure control and cardiovascular status are suitable for exercise; understand the medications you’re taking (some affect heart rate or blood pressure response during exercise); and follow a progressive approach. If you experience severe headache, chest tightness, or unusual breathlessness during exercise, stop immediately and seek medical attention.

---

Conclusion: Treat Your Kidneys as a Long-Term Teammate

Let’s return to A-Jhe at the beginning. After he recovered, I helped him rebuild his training plan. He stopped believing that “overtraining equals effort” and switched to a steady, progressive program, taking hydration and weather seriously. A year later, he not only finished that mountain race, but he did it with a better time than when he was desperately overtraining—and his kidney function tracking was all normal. This experience reinforced my belief: training smart takes you further than training hard.

Exercise and the kidneys were never enemies. The real enemies are ignorance, stubbornness, and the kind of muggy Taiwan summer heat that dehydrates you without you even noticing. For healthy people, regular exercise is a good habit that protects the kidneys. For kidney patients, appropriate exercise is a powerful tool for improving quality of life and fighting sarcopenia and cardiovascular risk. The difference is simply—whether you use the right methods and find the right balance.

Treat your kidneys as a silent but important long-term teammate. They don’t cry out in pain, so you need to think ahead for them: increase gradually, hydrate well, avoid the heat, and back off when your body raises the alarm. Do that, and they’ll keep you riding longer and running further.

---

This article is educational content and does not replace individualized diagnosis and treatment advice from physicians, physical therapists, or dietitians. Patients with chronic conditions such as kidney disease, diabetes, hypertension, or heart disease should consult their healthcare team for individualized assessment before starting or adjusting an exercise program. If you experience tea-colored urine, significantly decreased urine output, or severe and unusual muscle pain after exercise, seek medical attention promptly.

References

• Clinical Practice Guideline: Exercise and Lifestyle in Chronic Kidney Disease（BMC Nephrology）：https://bmcnephrol.biomedcentral.com/articles/10.1186/s12882-021-02618-1
• Physical activity and exercise in chronic kidney disease: consensus statements（Italian Society of Nephrology, PMC）：https://pmc.ncbi.nlm.nih.gov/articles/PMC11519309/
• Exercise-Induced Rhabdomyolysis Causing Acute Kidney Injury: A Potential Threat to Gym Lovers（PMC）：https://pmc.ncbi.nlm.nih.gov/articles/PMC9477545/
• Exercise and Kidney Health: Core Curriculum 2026（American Journal of Kidney Diseases）：https://www.ajkd.org/article/S0272-6386(25)01159-X/fulltext

Related Reading

• Liver and Kidney Burden in Athletes and the High-Protein Myth: Does High Protein Really Damage the Liver and Kidneys? Safety Limits and Population Differences Explained
• Nutrition Management for Diabetics and Exercise: A Coach’s Field Notes on Blood Sugar, Carbohydrate Adjustments, and Hypoglycemia Prevention
• Exercising with Chronic Illness: A Complete Guide to Safety, Quality of Life, and Lifestyle While Living with Disease
• Can You Exercise with Digestive Issues? A Safety Management Guide for Exercise and Gastrointestinal Disease