May 29, 2025
What Your Workouts Might Be Telling You About Your Liver Health
When intense exercise causes a spike in liver enzymes, it doesn’t always mean liver disease, but it does mean your body’s under stress.
Written by
Mito Team
What’s Going On When Liver Enzymes Spike?
If your blood test shows elevated liver enzymes, like ALT or AST, your first thought might be liver disease. But what if you’ve just come off a tough workout or long run?
It turns out that your liver enzymes can be temporarily elevated after an intense physical activity because of muscle damage. These enzymes, especially AST, are also found in your muscles. When muscle fibers break down, even from something as routine as strength training, these enzymes leak into your bloodstream.
This raises the question: What causes liver enzymes to spike, and is it always the liver’s fault?
Not necessarily.
Liver Enzymes 101: ALT, AST, and More
ALT (alanine aminotransferase) and AST (aspartate aminotransferase) are commonly measured on liver panels. While ALT is more concentrated in the liver, AST is found in both the liver and skeletal muscle, which complicates things.
If both are elevated, it could mean:
Liver inflammation resulting in hepatitis and fatty liver
Muscle damage, like from a workout or injury
Medication-induced injury or infection
Other enzymes help narrow it down:
Creatine kinase (CK), which rises with muscle damage
Gamma-glutamyl transpeptidase (GGT) is specific to the liver and bile ducts
Lactate dehydrogenase (LDH) is found in both the liver and the muscle
How Muscle Damage Mimics Liver Disease
When you work out intensely, especially with heavy lifting, long-distance running, or eccentric training, your muscles experience micro-tears.
This triggers a cascade: calcium leaks into muscle cells, then enzymes like CK, AST, and ALT are released. Next, oxidative stress damages cell membranes. These liver enzymes show in your bloodwork.
This is why suddenly elevated liver enzymes don’t always mean your liver is under attack. Your muscles might just be recovering.
In fact, one case study looked at a healthy 23-year-old guy who hit the gym hard and ended up with ALT of 277, AST of 580, and CK over 19,000. Sounds scary, but it was just muscle damage from the workout. His liver was fine, and all his levels went back to normal within three weeks after resting. A good reminder that not all liver enzyme spikes mean liver trouble—sometimes it's just your muscles talking.
Related: Blood Testing for Athletes: Why It Matters and What to Track
How to Tell If It’s Muscle, Not Liver
So if your labs come back high again, you might be wondering: Why do my liver enzymes keep going up? The answer might be your workout routine.
Here are some signs your enzymes are elevated because of muscle damage, not liver disease:
High CK levels
Normal GGT and bilirubin
You worked out hard in the last 48 to 72 hours
AST is higher than ALT
You’re feeling sore, tired, or recovering from a tough session
These clues, especially in combination, point to muscle, not liver, as the source. When muscle enzymes are high, symptoms like soreness, swelling, or weakness often show, too. If that sounds familiar, your labs are probably reflecting recovery, not disease.
Can Testosterone and Training Impact Enzyme Levels?
Does testosterone affect liver enzymes? Indirectly, yes.
Testosterone plays a role in muscle recovery. When levels are low or when your testosterone-to-cortisol ratio is off, it slows down your recovery and keeps enzymes like AST and ALT elevated longer. Overtraining, poor sleep, and stress can all throw off this balance.
On the flip side, using anabolic steroids raises liver enzymes, too. Sometimes because of actual liver strain, other times just from pushing your training volume to the extreme.
When Should You Worry?
Most of the time, elevated enzymes from exercise are short-lived. But some red flags should prompt a closer look:
ALT over 800 U/L
Enzymes stay high for more than 2 to 3 weeks
You’re not working out regularly
You have symptoms like jaundice, fatigue, dark urine, or abdominal pain
Also, if you’re dealing with liver and muscle pain or have a history of alcohol use, medication side effects, or metabolic issues, it’s worth digging deeper.
Beyond Muscle Damage: Causes of Elevated Liver Enzymes
Not all enzyme spikes are from exercise. Other common causes include:
Non-alcoholic fatty liver disease (NAFLD)
Viral hepatitis (A, B, C, etc.)
Alcohol use or liver-toxic medications
Autoimmune liver conditions
Genetic disorders like hemochromatosis
If your levels don’t settle down after rest, don’t guess. Mito Health can help you run a deeper blood panel and make sense of what’s going on in your liver health.
How to Reduce ALT and AST Naturally
If your enzymes are elevated, whether from training or actual liver stress, these strategies help:
Rest and recovery
Stay hydrated, especially after exercise
Eat anti-inflammatory foods like leafy greens, berries, and omega-3s
Limit alcohol and processed foods
Support detox with cruciferous veggies, such as broccoli and Brussels sprouts
Track your markers and recheck levels after 5 to 7 days of rest
Exercise-induced elevations usually resolve with time. But if you’re unsure, Mito Health can test deeper markers, like CK, GGT, and testosterone, and guide you through the next steps.
Don’t Panic, Get Context
Can liver enzymes be temporarily elevated? Absolutely, especially if you’re pushing your limits in the gym. What matters is the pattern, your symptoms, and whether you’re recovering well. If you're navigating sudden elevated liver enzymes, don't jump to conclusions. You might just be seeing the cost of muscle gains in your bloodwork.
With a personalized panel and smart interpretation, Mito Health helps you tell the difference between liver disease and muscle stress, and supports you in optimizing both.