Anaerobic Capacity: How to Increase, Exercises, Benefits
High altitude simulation is a performance tool that boosts anaerobic capacity, delays muscle fatigue and lactic acid buildup, and gives you a competitive edge that is entirely safe and legal.
This article covers hypoxia and hypercapnia, what anaerobic exercise is, what lactic acid does, how it affects athletic performance, and how breath hold exercises produce beneficial physiological adaptations.
When it comes to breathing techniques, athletes tend to focus on oxygenation. Whether you are new to sport or a seasoned pro, breathing efficiency is vital. It is a major differentiator for competition and performance.
But it is during anaerobic exercise that adaptations take place. This is when you push yourself beyond what oxygen alone can sustain. It is relatively easy to increase aerobic capacity. But anaerobic capacity is different. Repeated high intensity bursts can damage the body. Lactic acid burns in your muscles, and muscle fatigue strikes. You have to slow down or stop, whether you like it or not. The harder you push, the higher your injury risk.
Fatigue is an issue for every athlete, but it is particularly relevant in anaerobic exercise. It is the point at which it is physically impossible to continue at the same intensity. In chemical terms, it comes down to an increase in hydrogen ions in the blood.
Breathing Chemistry and Blood pH in Sports Physiology
Breathing involves the exchange of oxygen and carbon dioxide. It is vital for life, but also important for homeostasis, the maintenance of a healthy internal balance.
Breathing impacts the pH of the blood (how acid or alkaline your blood is). Normal blood pH is between 7.35 and 7.45. Even slight fluctuations can cause very serious effects. The level of carbon dioxide in the blood has a direct impact on blood pH. Too much CO2, and you get respiratory acidosis (the blood becomes too acidic). Too little, you get respiratory alkalosis (the blood becomes too alkaline).
What Do These Terms Mean?
An acid is a molecule that breaks down to form hydrogen ions (H+). Carbon dioxide in the blood forms carbonic acid (H2CO3). Carbonic acid breaks down to form hydrogen and bicarbonate ions.
When compounds like acids break into smaller parts, scientists call it dissociation. Dissociation is usually reversible. Molecules split into ions, atoms and radicals. When carbonic acid dissociates, it produces hydrogen and bicarbonate. The bicarbonate acts as a buffer, minimising the change in pH by mopping up hydrogen ions so the blood does not become too acidic.
pH is a measure of acidity and alkalinity, but it actually refers to the concentration of hydrogen ions. The concentration of H+ determines acidity and alkalinity.
How Does Hypoxic Training Work?
Simulation of high altitude training involves the practice of strong breath holds. This causes:
- Hypoxia: blood oxygen levels drop to between 80 and 90%. Normal blood oxygen concentration is between 95 and 100%. Anything less than 90% is hypoxic.
- Hypercapnia: blood carbon dioxide (CO2) increases. When blood CO2 is higher than normal, it is called hypercapnia.
Hypoxia and hypercapnia result in an increase in hydrogen ions. As H+ builds up, the blood acid-base balance changes. When you expose your body to a surge in H+ during training, the body adapts, reducing the onset of muscle fatigue.
When you hold the breath, CO2 cannot leave the body. It builds up in the lungs, blood and muscles (hypercapnia). It forms carbonic acid, which dissociates to H+ and bicarbonate.
When oxygen levels are normal, H+ oxidises in the cells to form water. When oxygen is low (hypoxia), oxidisation cannot take place. In these anaerobic conditions, H+ combines with pyruvic acid, a byproduct of glycolysis — the metabolism of glucose that supplies energy to the cells. When pyruvic acid combines with hydrogen, it forms lactic acid. Lactic acid then dissociates into H+ and lactate ions, where lactate acts as the buffer.
During breath holding to simulate altitude training, the muscles become acidic. This is the main cause of adaptations that occur after training. Scientists suggest the body develops an enhanced buffering capacity, meaning H+ accumulates more slowly and you can keep going for longer.
What Happens During Anaerobic Exercise?
Anaerobic means "without oxygen." Anaerobic exercise is any type of exercise that breaks down glucose for energy without using oxygen. Think high-intensity, short-burst activities: HIIT, weightlifting, MMA, sprinting and boxing. Pushing beyond your VO2 max.
During aerobic exercise, the body uses oxygen to get energy from fat and glucose. When you train hard, your muscles experience a temporary shortage of oxygen. This means your body must get energy from glycolysis (anaerobic metabolism), which uses glucose stored in the muscles for energy and produces energy fast. But as we have seen, it also produces lactic acid.
Benefits of Anaerobic Exercise
- Greater power
- Better bone mineral density
- Enhanced metabolism
- Weight management
- Less depression
- Lower risk of disease
- More energy
- Increased lactate threshold
When you practice anaerobic capacity exercises, your body will adapt. High altitude simulation increases your body's lactate threshold, improving your body's tolerance to lactic acid. Muscle fatigue and lactic acid accumulation are closely related, so a better lactate threshold means better anaerobic capacity. This delays the onset of fatigue, improves performance, and means you can train harder for longer without risk of overtraining.
What Is Lactic Acid?
Lactic acid is a metabolic byproduct most familiar from exercise. But if there is not enough oxygen present, all cells produce lactic acid. This can cause metabolic acidosis, producing symptoms including nausea, weakness and vomiting, particularly in people with a compromised liver.
Lactic acid causes the burning sensation in your muscles when you are pushing hard. But it is frequently misunderstood. Lactic acid is not always the bad guy.
Does Lactic Acid Cause Muscle Fatigue?
When blood lactate levels are high, muscle cells become more acidic. This makes it difficult for the body to break down glucose to get energy. The acidic environment also blocks nerve signals from the brain to the muscles. Your legs begin to feel heavy, and you slow down.
This process might seem counterproductive. Why does the working muscle produce a substance that slows it down? The answer is that it prevents overtraining and long-term damage during extreme exercise. It protects you from permanent injury.
Once the body has slowed down, oxygen becomes available again. Lactate reverts back to pyruvate, and aerobic metabolism recommences. This gives your body the energy it needs for recovery. George Brooks, professor of integrative biology at UC Berkeley, says "lactate production is a strain response, it is there to compensate for metabolic stress."
Lactic acid buildup does not cause muscle soreness in the days after intensive exercise, contrary to what many people believe. The burning sensation causes us to stop overworking the body and forces a period of recovery. The delayed-onset muscle soreness (DOMS) that happens two or three days later is due to tiny tears in the muscle tissue. Research has shown that hypoxia is beneficial in muscle repair, both in the formation of muscle tissue and the stimulation of muscle stem cells.
How Does Lactic Acid Affect Breathing?
Scientists have proven that exercise-induced lactic acidosis plays a role in hyperventilation. This hyperventilation starts at the respiratory compensation point (RCP), the point at which the pressure of arterial oxygen begins to drop during intense exercise. When oxygen is absent, every cell will produce lactic acid. But this is not the only thing that stimulates breathing during heavy exercise. Sensory inputs from exercising muscles also contribute.
Lactic acid is also not the only cause of heavy legs. When the breathing muscles tire, the body diverts blood circulation from the legs to support breathing. Strong breathing muscles and breathing efficiency are also important in delaying muscle fatigue. You can develop your breathing muscles with high altitude simulation training.
How Do I Reduce Lactic Acid?
Scientists have proven that athletes who practice breathing exercises can increase their performance without increasing lactic acid buildup. It is also important to:
- Stay hydrated
- Breathe light for better oxygenation
- Use breathing exercises during warm-up and recovery
- Restore full-time nasal breathing
- Practice exercises to simulate high altitude training
Injured athletes can also use breath hold exercises to simulate high altitude training and maintain condition during recovery.
How Do You Increase Your Anaerobic Threshold?
Your anaerobic threshold is your lactic acid threshold. They are two ways of describing the same thing. And better anaerobic capacity can mean the difference between winning and losing.
Scientists have shown that altitude training increases lactic acid tolerance, allowing your body to handle a higher lactic acid level before getting tired. Altitude training also boosts cardiorespiratory fitness and improves running speed, even when lactic acid is present in the muscles.
Many people rely on elevation masks to recreate conditions at high altitude. But masks do not work that way. They increase resistance to airflow and build-up of carbon dioxide, but they do not reduce the pressure of oxygen.
To recreate the hypoxia and hypercapnia typical of high altitudes, integrate the Oxygen Advantage anaerobic capacity exercises into your workout. Anaerobic training can be demanding. But with the right breathing exercises, you can experience the benefits without the burn.
You can track your progress using the BOLT score. As your CO2 tolerance improves and your anaerobic capacity increases, your BOLT score will rise — reflecting better breathing efficiency and a higher lactate threshold.
Research: Breath Training and Anaerobic Capacity
Study 1: Hypoventilation training improves swimming performance and anaerobic capacity
Time performance was significantly improved in trials involving breath holding following an exhalation (100m: –4.4%; 200m: –3.6%; 400m: –3.5%) but did not change in controls. Maximal lactate concentration and the rate of lactate accumulation in blood were higher post-training in the breath hold group, indicating a greater glycolytic activity. Increased lactate max reflects improved anaerobic capacity and a greater ability to tolerate high concentrations of lactate and high levels of acidosis.
Woorons X, Mucci P, Richalet JP, Pichon A. Hypoventilation Training at Supramaximal Intensity Improves Swimming Performance. Med Sci Sports Exerc. 2016;48(6):1119-28.
Study 2: Reduced breathing frequency delays the appearance of blood lactate
Five male subjects performed 16 sets of 4-minute cycling bouts. Breathing frequency was voluntarily controlled using four different patterns: normal breathing, breathing every 4 seconds, breathing every 8 seconds, and maximal reduced frequency breathing. Except for the normal breathing trials, subjects held their breath at functional residual capacity. The researchers concluded that reduced breathing frequency inhibited lactate removal from working muscles during exercise.
Yamamoto Y, Takei Y, Mutoh Y, Miyashita M. Delayed appearance of blood lactate with reduced frequency breathing during exercise. Eur J Appl Physiol Occup Physiol. 1988;57(4):462-6.
Study 3: Prolonged expiration to residual volume increases buffering capacity
Repeated prolonged expirations carried out down to residual volume during submaximal exercise led to a drop of SaO2 to 87% and were accompanied by marked hypercapnia. The prolonged expiration led to greater blood acidosis, mainly hypercapnic and possibly also linked to greater muscle acidosis, exposing the body to conditions that stimulate improved buffering capacity.
Woorons X et al. Prolonged expiration down to residual volume leads to severe arterial hypoxemia in athletes during submaximal exercise. Respiratory Physiology and Neurobiology. 2007;158:75-82.
Study 4: Breath hold training reduces blood acidosis and eliminates oxidative stress
Repeated epochs of breath holding were added to the regular training cycling program of triathletes. After training, the duration of static apnea significantly lengthened and the associated bradycardia was accentuated. A reduction of the post-apnea decrease in venous blood pH and increase in lactic acid concentration was noted, along with suppression of post-apnea oxidative stress. After dynamic apnea, blood acidosis was reduced and oxidative stress no longer occurred. These results suggest that breath holding improves tolerance to hypoxaemia independently of any genetic factor.
Joulia F et al. Breath-hold training of humans reduces oxidative stress and blood acidosis after static and dynamic apnea. Respir Physiol Neurobiol. 2003;137(1):19-27.
Study 5: Elite breath-hold divers show reduced oxidative stress and lactic acidosis
Trained divers with 7 to 10 years of breath-hold diving experience were compared to control individuals. In divers, changes in lactic acid and oxidative stress markers were markedly reduced after static and dynamic apnea, as well as after control exercise. Long-duration breath-hold training programmes reduce post-apnea and post-exercise blood acidosis and oxidative stress, mimicking the responses of diving animals.
Joulia F et al. Reduced oxidative stress and blood lactic acidosis in trained breath-hold human divers. Respir Physiol Neurobiol. 2002;133(1-2):121-30.
Study 6: Repeated sprint training in hypoxia improves sprint ability through enhanced anaerobic glycolysis
Repeated-sprint training in hypoxia had been shown to improve repeated sprint ability in team-sport players, but had not been investigated in swimming. This study found that repeated sprint training in hypoxia induced by voluntary hypoventilation at low lung volume improved repeated sprint ability in swimming, probably through enhanced anaerobic glycolysis. This method allows inducing benefits normally associated with hypoxia during swim training in normoxia.
Trincat L, Woorons X, Millet GP. Repeated Sprint Training in Hypoxia Induced by Voluntary Hypoventilation in Swimming. Int J Sports Physiol Perform. 2016.
Study 7: Voluntary hypoventilation induces lower muscle oxygenation and higher blood lactate
This study demonstrated that exercise with voluntary hypoventilation induced lower tissue oxygenation and higher blood lactate concentration than exercise with normal breathing. This was caused by severe arterial O2 desaturation induced by both hypoxic and hypercapnic effects. Eight men performed five-minute cycling bouts in four conditions varying in breathing pattern and inspired oxygen fraction.
Woorons X et al. Exercise with hypoventilation induces lower muscle oxygenation and higher blood lactate concentration: role of hypoxia and hypercapnia. Eur J Appl Physiol. 2010;110(2):367-77.
Study 8: Intermittent breath holding causes consistent changes in muscle oxygenation
Thirteen men performed bicycle exercise with normal breathing and with intermittent breath holding. Near-infrared spectroscopy showed acute changes with each breath hold episode: total haemoglobin and oxyhaemoglobin decreased, deoxyhaemoglobin increased. Blood lactate levels were significantly greater in the intermittent breath holding condition. These results suggest that intermittent breath holding during moderate exercise provokes consistent changes in muscle oxygenation leading to lower tissue oxygenation.
Kume D et al. Intermittent breath holding during moderate bicycle exercise provokes consistent changes in muscle oxygenation and greater blood lactate response. J Sports Med Phys Fitness. 2013;53(3):327-35.
Study 9: Voluntary hypoventilation training reduces exercise-induced blood acidosis
Two groups of moderately trained runners completed a training period, one using voluntary hypoventilation (HYPO, n=7) and one control group (CONT, n=8). The hypoventilation group ran 24 minutes at 70% of VO2 max with breath holding at functional residual capacity. The results demonstrate that voluntary hypoventilation training could modify glycolytic metabolism. The reduced exercise-induced blood acidosis in the hypoventilation group is likely due to an improvement in muscle buffer capacity, which may have a significant positive impact on anaerobic performance.
Woorons X et al. Effects of a 4-week training with voluntary hypoventilation carried out at low pulmonary volumes. Respir Physiol Neurobiol. 2008;160:123-130.
Study 10: Voluntary hypoventilation at low lung volume improves repeated sprint ability in swimming
Sixteen competitive swimmers completed six sessions of repeated sprints with either voluntary hypoventilation at low lung volume (RSH-VHL, n=8) or normal breathing (RSN, n=8). From pre- to post-training, the number of sprints was significantly increased in RSH-VHL (7.1 to 9.6 sprints; p<0.01) but not in RSN. Maximal blood lactate concentration was higher at post-training in RSH-VHL only. There was a strong correlation between sprint improvement and lactate increase in RSH-VHL (R=0.93; p<0.01).
Trincat L, Woorons X, Millet GP. Repeated Sprint Training in Hypoxia Induced by Voluntary Hypoventilation in Swimming. Int J Sports Physiol Perform. 2016.
Study 11: Voluntary hypoventilation during exercise augments electromyography activity
Seven men performed five-minute bicycle exercise with normal breathing and with voluntary hypoventilation. In the voluntary hypoventilation condition, oxyhaemoglobin was significantly lower and deoxyhaemoglobin significantly higher compared to normal breathing. Integrated EMG was significantly higher during voluntary hypoventilation. This study suggests that voluntary hypoventilation during exercise augments muscle electrical activity.
Kume D et al. Does voluntary hypoventilation during exercise impact EMG activity? Springerplus. 2016;5:149.
Build Anaerobic Capacity with Oxygen Advantage
The Oxygen Advantage method gives athletes a practical, evidence-based way to increase anaerobic capacity without the injury risk of pure high-intensity training. By using breath hold exercises to simulate high altitude, you raise your lactate threshold, improve your buffering capacity, and delay the onset of fatigue, all while training at a manageable intensity.
The method is also relevant for swimmers, cyclists, runners, and team sport athletes looking to improve repeated sprint ability. Injured athletes can use the exercises to maintain condition during periods of forced rest.
If you are interested in trying the OA method for yourself, why not try our online breathing course, become a certified breathwork instructor, or find an Oxygen Advantage instructor near you.