Anaerobic threshold and lactate training for freedivers

Joel Jamieson revolutionized conditioning for combat athletes by mapping out energy systems with scientific precision. His insight? Most fighters train randomly, never targeting the specific metabolic demands of their sport. They do generic cardio hoping it transfers to performance.

The anaerobic threshold isn’t just for marathon runners or cyclists. It matters for any sport that requires repeated high-intensity efforts with incomplete recovery. And while freediving breath-holds rely on stored oxygen, the movement component-finning, swimming underwater, dynamic disciplines-creates significant lactate demands that most freedivers never train systematically.

Your legs burn out before your breath does? That’s a lactate problem, not a lung problem.

Understanding your lactate system

Lactate gets a bad reputation as the “waste product” that makes your muscles burn. That’s outdated science. Lactate is actually fuel-your body’s way of rapidly producing energy when oxygen demand exceeds supply. The burning sensation comes from the hydrogen ions produced alongside lactate, not the lactate itself.

During intense muscular work-like finning hard underwater or swimming repeated dynamic laps-your muscles produce lactate faster than they can clear it. This accumulation leads to that familiar burning sensation in your legs, compromised technique, and eventually forced rest.

For freedivers, this shows up in:

Dynamic swimming sessions. Each underwater lap produces lactate in your working muscles. Poor lactate tolerance means fewer quality attempts before your legs give out.

Finning endurance. Whether you’re swimming laps in the pool or covering distance underwater, sustained kicking creates progressive lactate buildup. Your technique degrades as your muscles fatigue.

Recovery between efforts. How quickly you clear lactate determines how fresh you feel for the next attempt. Poor lactate clearance means carrying fatigue from one dive to the next.

The key insight: lactate tolerance and clearance are trainable. Your body can get dramatically better at producing energy through this system and clearing the byproducts efficiently.

Where lactate limits your diving

Most freedivers focus entirely on breath-holding capacity and ignore the muscular endurance that supports their underwater movement. This creates a bottleneck: your cardiovascular system might be ready for another dive, but your legs are still burning from the last effort.

Poor lactate tolerance shows up as:

Burning legs that force early surfacing. You have breath left, but your finning becomes inefficient and unsustainable. This is pure lactate accumulation.

Degraded technique under fatigue. As lactate builds up, your kick becomes less powerful and less efficient. You’re working harder for less forward progress.

Long recovery times between efforts. If you need 5+ minutes between dynamic attempts, your lactate clearance needs work. Efficient athletes can repeat high-intensity efforts with much shorter rest periods.

Session fatigue. Your first few dynamic attempts feel strong, but quality drops rapidly as the session progresses. This is cumulative lactate stress overwhelming your clearance capacity.

The cascade effect: when your legs are burning from lactate, it’s harder to stay relaxed. Muscle tension increases oxygen consumption and affects your ability to maintain efficient underwater positioning. Poor lactate tolerance doesn’t just limit your finning-it compromises your entire dive quality.

Training your lactate threshold

Jamieson’s approach to lactate training is methodical: identify the intensity that maximally stresses the lactate system, then train at that intensity with appropriate work-to-rest ratios.

For freedivers, this can be approached through both pool-based and land-based training:

In the pool: Underwater intervals and dynamic swimming sets at high but sustainable intensities. The key is working at an effort level that creates significant lactate buildup while still allowing you to complete multiple repetitions.

On land: Cycling, running, or rowing intervals that target the same energy system. The advantage here is you can push the lactate system hard without the complexity of breath control.

The beauty of land-based lactate training is isolation-you’re overloading the specific energy system that limits your underwater movement without the technical demands of freediving.

General principles: This type of training requires significant recovery between sessions and should be scheduled separate from technical freediving work when possible. The systematic approach aligns with Progressive Training: Why Freedivers Need to Stop Winging It-structured progression beats random efforts.

Fitting it into your training

Smart lactate training doesn’t replace freediving practice-it supports it. Like any training component, lactate work needs to be periodized appropriately within your overall program. During certain phases, you might emphasize lactate development, while other phases focus more on technique or breath-holding capacity.

This is where Stop Wasting Your Pool Time becomes relevant. Instead of random underwater swimming, you’re strategically targeting specific energy systems with measurable progression.

Lactate training won’t directly improve your breath-holding capacity. But it will eliminate the muscular fatigue, letting you train your breath-holding skills more consistently.