What Is Lactate?
Lactate is a naturally occurring substance produced by the body during exercise and energy metabolism. Once blamed for fatigue and declining performance, modern sports science now recognises lactate as an important fuel source and signalling molecule that plays a central role in energy production, endurance, adaptation and recovery.
Introduction
For decades, athletes were taught to fear lactate.
The story seemed straightforward.
Exercise harder.
Lactic acid builds up.
Muscles burn.
Performance drops.
The more lactate you produce, the worse things get.
Today, sports science tells a very different story.
One of the most important discoveries in modern exercise physiology is that lactate is not simply a byproduct of hard exercise.
It is part of the solution.
Rather than being a sign that the body is failing, lactate is now recognised as an important part of how the body produces, transports and manages energy during exercise.
This shift has fundamentally changed how coaches, physiologists and athletes think about performance, endurance and recovery.
What Is Lactate?
Every movement requires energy.
Whether walking, running, cycling or training, the body must continually produce adenosine triphosphate (ATP), the primary energy currency of human cells.
To meet this demand, the body breaks down carbohydrates and other fuel sources.
Lactate is produced as part of this normal process.
Importantly, lactate is not something that only appears during intense exercise.
The body produces lactate:
• At rest
• During everyday activity
• During training
• During competition
• During high intensity exercise
As exercise intensity increases, lactate production typically increases as well.
This is a normal part of exercise metabolism.
The Discovery That Changed Sports Science
For many years, lactate was viewed as a waste product.
Research over the past several decades has dramatically changed that understanding.
Scientists now know that lactate can:
• Be transported between tissues
• Be used as fuel by muscles
• Be utilised by the heart
• Be converted back into glucose
• Play a role in metabolic signalling
Professor George Brooks' Lactate Shuttle theory helped demonstrate that lactate acts as an intermediary fuel source that helps distribute energy throughout the body. (1)
Rather than being metabolic waste, lactate is increasingly viewed as part of the body's energy recycling system.
The body is constantly producing, transporting and utilising lactate.
Performance often depends less on whether lactate is produced and more on how effectively it can be used.
Why Does Lactate Increase During Exercise?
As exercise intensity rises, energy demand rises with it.
The body must generate ATP more rapidly to support working muscles.
This increases carbohydrate metabolism and, as a result, lactate production.
This is particularly noticeable during:
• Sprint efforts
• Interval training
• Hill running
• High intensity cycling
• HYROX competitions
• Endurance racing
Importantly, rising lactate does not automatically mean something is going wrong.
In many cases, it simply reflects the body's attempt to meet increasing energy demands.
What Is Lactate Threshold?
If there is one lactate metric endurance athletes should understand, it is lactate threshold.
Lactate threshold refers to the exercise intensity at which lactate begins accumulating faster than the body can clear or utilise it.
When this occurs:
• Fatigue typically increases
• Exercise becomes more difficult to sustain
• Performance eventually declines
Athletes with a higher lactate threshold can generally maintain faster speeds, higher power outputs and greater exercise intensity for longer periods.
This is why lactate threshold testing is widely used in:
• Running
• Cycling
• Triathlon
• Rowing
• Endurance sport
For many athletes, improving lactate threshold is one of the most effective ways to improve endurance performance.
Why Lactate Matters Beyond Training
One of the biggest mistakes athletes make is viewing lactate only through the lens of exercise.
Lactate also plays an important role in recovery.
Following training, the body begins restoring balance, repairing tissues and preparing for future demands.
Researchers continue to investigate how different recovery strategies may influence:
• Lactate response
• Tissue oxygenation
• Hydration status
• Energy metabolism
• Perceived fatigue
This is particularly relevant for athletes training frequently, competing on consecutive days or managing demanding schedules.
The quality of recovery often determines the quality of the next training session.
What Does The Research Say About Oxygen And Lactate?
As interest in recovery and exercise metabolism has grown, researchers have explored how oxygen availability may influence selected physiological responses during exercise.
A randomised, double blind, placebo controlled crossover study conducted by researchers at the University of Roehampton investigated the effects of KURE during steady state aerobic exercise in trained female athletes. (3)
Researchers observed:
• Lower blood lactate concentrations during exercise
• Lower carbohydrate oxidation at specific time points
• Lower respiratory exchange ratio (RER)
• Differences in fat oxidation
The researchers concluded:
"Acute oxygenated water ingestion altered selected metabolic responses during steady state exercise."
Rather than measuring race performance outcomes, the study focused on selected metabolic responses during exercise.
Research conducted by London South Bank University also explored KURE's effects on recovery related markers. (4)
Researchers reported:
• Lower post exercise lactate levels
• Increased tissue oxygenation
• Improvements in hydration status
• Faster blood pressure recovery following exercise
While further research is required, these findings have contributed to growing interest in oxygen supported hydration within performance and recovery discussions.
Recovery Is Where Performance Is Built
Many athletes focus on training.
Elite performers focus on adaptation.
Training creates stress.
Recovery is where adaptation occurs.
Without adequate recovery, progress becomes difficult to sustain.
This is why modern performance systems increasingly emphasise:
• Sleep
• Hydration
• Nutrition
• Recovery planning
• Load management
Rather than viewing recovery as separate from performance, many coaches now view recovery as part of performance itself.
The athletes who recover effectively are often the athletes who can train consistently.
Common Misconceptions About Lactate
Lactate Causes Fatigue
Not directly.
Fatigue is influenced by numerous physiological factors, including energy availability, neuromuscular function and metabolic stress.
Lactate Is A Waste Product
Modern research suggests lactate is an important fuel source and signalling molecule involved in exercise metabolism. (1)
More Lactate Means Poor Fitness
Not necessarily.
Highly trained athletes often produce substantial amounts of lactate during intense exercise.
The difference is that they are often better at utilising it.
Lactate Should Be Eliminated
Lactate production is a normal and necessary part of exercise metabolism.
The goal is not to eliminate lactate.
The goal is to improve how efficiently the body manages it.
FAQs
What Is Lactate?
Lactate is a naturally occurring substance produced during energy metabolism and exercise.
Is Lactate The Same As Lactic Acid?
Not exactly. While the terms are often used interchangeably, modern exercise physiology focuses primarily on lactate rather than lactic acid.
Does Lactate Cause Muscle Soreness?
No. Delayed onset muscle soreness (DOMS) is not caused by lactate accumulation.
What Is Lactate Threshold?
Lactate threshold refers to the exercise intensity at which lactate begins accumulating faster than it can be cleared or utilised.
Why Is Lactate Important?
Lactate functions as both a fuel source and a signalling molecule involved in energy metabolism and exercise adaptation.
Can Recovery Strategies Affect Lactate Response?
Researchers continue to investigate how hydration, oxygen availability and recovery practices may influence lactate related responses during and after exercise.
What Role Does KURE Play?
KURE is a functional oxygen supplement delivered in Cornish spring water designed to fit naturally into training, recovery and active lifestyles. Research has explored its effects on selected metabolic and recovery related markers, including lactate responses during and after exercise.
Key Takeaways
• Lactate is not simply a waste product.
• Modern sports science recognises lactate as both a fuel source and signalling molecule.
• Lactate is part of the body's energy management system.
• Lactate threshold is one of the most important markers of endurance performance.
• Recovery plays a major role in managing training stress and adaptation.
• Researchers continue to explore how oxygen supported hydration may influence selected metabolic and recovery related markers.
• Long term performance is built through consistent training and effective recovery.
Conclusion
Few ideas in sports science have changed as dramatically as our understanding of lactate.
For decades, athletes were taught to see lactate as the enemy.
Modern research tells a different story.
Lactate is not simply something the body must get rid of.
It is part of how the body produces, transports and reuses energy.
The athletes who perform best are not necessarily those who produce the least lactate.
They are often the ones who learn to use it most effectively.
Understanding that shift may be one of the most important lessons in modern endurance training.
As sports science continues to evolve, attention is increasingly turning towards strategies that support recovery, readiness and exercise metabolism.
KURE was developed to fit naturally into that conversation as a functional oxygen supplement delivered in Cornish spring water, designed to support the routines athletes already rely on as they train, recover and perform.
References
(1) Brooks, G.A.
The Lactate Shuttle During Exercise and Recovery
https://pubmed.ncbi.nlm.nih.gov/26477616/
(2) American College of Sports Medicine
Lactate and Exercise Metabolism
https://www.acsm.org
(3) University of Roehampton
Randomised Double Blind Placebo Controlled Crossover Study Investigating KURE During Steady State Aerobic Exercise in Trained Female Athletes
(4) London South Bank University
Exploring the Physiological Effects and the Ergogenic Potential of Oxygen Enriched Water in Exercise Performance
(5) Harvard Health
Exercise Physiology and Aerobic Fitness
https://www.health.harvard.edu
