The Purpose of Lactic Acid in Bodybuilding: Friend or Foe?
When it comes to pushing through tough training sessions and achieving muscle growth, few topics spark as much debate as lactic acid in bodybuilding. Often misunderstood and unfairly blamed for muscle soreness, lactic acid actually plays a far more complex and interesting role in physical performance and muscle development. In this post, we’ll explore what lactic acid really is, how it affects your body during workouts, and what bodybuilders should know to train smarter and recover better.
What Is Lactic Acid?
Lactic acid is a by-product of anaerobic metabolism. When you engage in high-intensity exercise such as weightlifting or sprinting, your muscles require energy at a rate faster than oxygen can be delivered to them. To keep producing energy, your body switches to a process called anaerobic glycolysis, which breaks down glucose without oxygen. This process leads to the production of lactic acid.
However, it’s worth noting that the term lactic acid is often used interchangeably with lactate, even though they are technically different. In the body, lactic acid quickly dissociates into lactate and hydrogen ions. It’s the build-up of these hydrogen ions that contributes to the burning sensation felt during intense exercise—not the lactate itself.
The Role of Lactic Acid in Bodybuilding
For decades, lactic acid in bodybuilding was vilified. Many assumed it was responsible for post-workout muscle soreness—what’s known as DOMS (Delayed Onset Muscle Soreness). However, scientific research has since debunked this myth. DOMS is more closely linked to microscopic muscle damage, especially from eccentric movements, rather than lactate build-up.
In reality, lactate serves several important functions in bodybuilding:
1. A Temporary Energy Source
When oxygen is scarce, lactate becomes an alternative fuel. It can be transported to other tissues such as the heart or liver, where it’s converted back into glucose for more energy. This process, known as the Cori cycle, is a vital backup during high-intensity training when energy demands exceed oxygen supply.
2. A Signal for Muscle Adaptation
Lactate accumulation acts as a cellular signal for the body to adapt to training stress. It stimulates the release of anabolic hormones like growth hormone and testosterone. These hormones are crucial for muscle hypertrophy, making lactic acid in bodybuilding not just a by-product, but a promoter of growth and recovery.
3. Muscle Endurance and Conditioning
Training that leads to lactate build-up—such as supersets, drop sets, or high-rep circuits—forces your body to become more efficient at buffering and clearing lactate. This increases muscular endurance and enhances your ability to sustain high-intensity efforts over time. For competitive bodybuilders and athletes alike, this can lead to better overall conditioning and performance.
The ‘Burn’ and Its Benefits
That burning feeling during your final reps? That’s hydrogen ion accumulation, not lactate itself. But it’s a sign that your body is pushing hard. Rather than avoiding this sensation, many bodybuilders embrace it as a cue for effective muscle stimulation. Workouts that create significant lactate build-up can trigger metabolic stress, one of the three primary mechanisms of muscle growth (alongside mechanical tension and muscle damage).
How to Use Lactic Acid Training in Your Programme
If you’re looking to harness the benefits of lactic acid in bodybuilding, consider incorporating techniques like:
High-rep sets (12–20 reps) with short rest periods
Supersets (two exercises performed back-to-back without rest)
Drop sets (reducing weight and continuing to failure)
Tempo training, especially with slow eccentrics
These methods elevate lactate levels and stimulate metabolic stress, promoting muscular growth through hormonal responses and increased cellular fatigue.
Recovery and Lactic Acid
Although lactic acid isn’t responsible for soreness days later, its accumulation can temporarily affect performance. Proper recovery strategies—such as active rest, hydration, stretching, and mobility work—can help clear lactate more efficiently. Consistent conditioning work, like light cardio or low-intensity weight training, also helps your body become more efficient at dealing with lactate.
Final Thoughts
Lactic acid in bodybuilding is no longer the villain it was once thought to be. Rather than causing damage, lactate plays a vital role in energy production, muscle growth, and metabolic adaptation. By understanding how lactic acid works—and by training with intention—bodybuilders can use this physiological process to their advantage.
So next time you feel the burn, don’t fear it—embrace it. That’s your body telling you it’s working hard, growing stronger, and adapting to the challenges you’re throwing at it. And in the world of bodybuilding, that’s exactly what you want.
The article ‘lactic acid in bodybuilding’ was written and first published on behalf of Bill Jones Mr Universe on Wednesday 7th May 2025 at 12:30 and is subject to copyright. All rights are reserved.
If you liked this article, you might also like this one, called ‘working out with injury‘. Also, here’s an article from my personal website that you might like, called ‘bodybuilding enhances life expectancy‘.