Author: Nick Pelios
Freedivers spend an enormous amount of time thinking about oxygen. We train to use less of it, tolerate lower levels of it and remain functional as it becomes progressively less available. We talk about relaxation, heart rate, the diving response, blood shift, hypoxia, carbon dioxide and efficiency. It makes sense. The defining characteristic of freediving is that we perform while voluntarily holding our breath. But oxygen is only part of the energy story. Your muscles still need energy to kick. Your diaphragm remains active. Your heart continues beating. Your nervous system is working constantly. During dynamic apnea, muscles continue contracting while oxygen availability progressively decreases. During a depth dive, the legs have to produce enough force to overcome positive buoyancy during the beginning of the descent and again during the increasingly demanding final part of the ascent. Between dives, the body has to recover and prepare to perform again. None of that happens for free.
Carbohydrates are one of the body's major sources of energy, and their role in athletic performance has been studied for more than a century. They are broken down into glucose, stored primarily as glycogen in the muscles and liver, and used to help regenerate ATP, the immediately usable form of energy required for muscular contraction and countless other cellular processes. For freedivers, however, the conversation needs some nuance. Freediving is not marathon running. It is not cycling, weightlifting or conventional swimming. We cannot simply take carbohydrate recommendations developed for other sports and assume that they apply perfectly to apnea. Research specifically examining carbohydrate intake and freediving performance remains limited. What we can do is understand the underlying physiology, look carefully at the evidence that does exist, and stop thinking about carbohydrates as either something athletes must constantly load or something serious freedivers should avoid. The more useful question is what job carbohydrates are actually doing and how that fits into the unusual demands of freediving.
From Food To ATP
When we eat carbohydrates, digestion eventually provides the body with glucose and other simple sugars that can enter metabolism. Some glucose is used immediately and some is stored, particularly as glycogen in skeletal muscle and the liver. Muscle glycogen acts as a local energy reserve. When a muscle needs energy, glycogen can be broken down and its glucose units fed into metabolic pathways that ultimately help regenerate ATP. Liver glycogen performs a somewhat different role, helping maintain blood glucose so that glucose remains available to tissues throughout the body. ATP is where all of this becomes relevant to movement. A muscle does not contract because you ate pasta the night before. It contracts because ATP provides usable chemical energy at the cellular level. The body therefore has to continually regenerate ATP throughout exercise.
Carbohydrate is particularly valuable because it can support ATP production through both aerobic and anaerobic pathways. When oxygen is sufficiently available, carbohydrate can be metabolized through pathways that ultimately involve oxidative phosphorylation. When ATP needs to be generated rapidly and oxygen availability cannot fully meet demand, carbohydrate can also contribute through glycolysis without requiring oxygen directly at that stage. That distinction matters because exercise intensity changes which fuels the body relies upon. As intensity increases, carbohydrate generally becomes increasingly important to working muscle. Fat is also an enormous energy reserve, and at lower exercise intensities it can contribute substantially to energy production. The body is not a machine that suddenly switches completely from one fuel to another. Fat and carbohydrate metabolism operate simultaneously, with their relative contributions changing according to intensity, duration, training status, diet and fuel availability.
This is one reason arguments about whether carbohydrates or fats are the "better" fuel tend to be less useful than they sound. Human metabolism uses both. The question is which substrate can best support the task being performed. Freediving makes that question particularly interesting because the objective is not simply to produce as much energy as possible. It is to produce the movement required while keeping the total metabolic cost as low as possible. A good freediver is economical. Watch an experienced athlete beside a beginner and the difference can be obvious. The experienced diver may cover the same distance with fewer unnecessary movements, better body position, cleaner kicks and less muscular tension. Both divers are producing energy, but one is spending it more intelligently. This is why technique is effectively part of freediving metabolism. Every unnecessary muscular contraction has an energetic cost. Tension has a cost. Poor streamlining has a cost because additional propulsion must compensate for additional resistance. An inefficient kick has a cost. Nutrition can provide fuel, but it cannot make inefficient movement efficient.
The Carbohydrate Question Gets More Complicated Underwater
If carbohydrates are an important exercise fuel, it would be easy to conclude that freedivers should simply consume more carbohydrates before diving. This is exactly where things become more complicated. A freediver does not necessarily want to begin a depth session with a large amount of food sitting in the stomach. A full stomach can interfere with comfort, diaphragm movement and the overall sensation of a deep dive. Digestion itself requires physiological activity. Many divers therefore develop very individual routines around meal size and timing before depth training. The fact that carbohydrate is important to energy metabolism does not mean a large carbohydrate-heavy meal immediately before getting on the line is automatically a good idea.
There is some direct freediving research showing why simplistic nutrition advice is difficult here. One small study examined eight divers performing a 30-metre breath-hold dive under two conditions. In one condition they dived three hours after a normal breakfast. In another, they followed a dietary intervention and then fasted overnight before the dive. During the fasting condition, the static phase incorporated into the dive was longer, blood lactate after surfacing was lower and arterial oxygen saturation was higher despite the longer dive. The researchers suggested that the metabolic and splanchnic conditions associated with fasting may have influenced the diving response. It is an interesting finding, but eight divers performing a particular experimental protocol is nowhere near enough evidence to tell freedivers that fasting improves performance, and it certainly is not evidence that carbohydrates should be avoided.
This distinction matters because there is a major difference between arriving at a depth session with an empty or relatively empty stomach and living or training with chronically low carbohydrate availability. There is also a difference between what feels good immediately before one dive and what supports an athlete across an entire week of training. A freediver might prefer to dive several hours after eating because the stomach feels comfortable. That does not mean the muscles need to begin the session with depleted glycogen. Glycogen stored from meals consumed many hours earlier, including meals from the previous day, remains available. Fueling does not necessarily mean eating immediately before the dive. The body has storage. That is the entire point of glycogen. A diver can therefore arrive at the boat without a heavy breakfast sitting in the stomach while still having adequate carbohydrate availability from their broader diet. These are not contradictory ideas.
Research in experienced breath-hold divers also suggests that glucose metabolism is actively involved during diving. One study involving experienced breath-hold divers measured blood glucose, insulin and catecholamines before and after repeated breath-hold dives and observed changes in glucose and hormonal responses following the diving session. The exact metabolic consequences of those changes are not yet sufficiently understood to translate them into a specific freediving nutrition protocol, but the broader point is useful. Apnea does not suspend normal energy metabolism. You may have stopped breathing, but your cells have not stopped working. The body still has to regulate fuel availability while simultaneously responding to hypoxia, carbon dioxide accumulation, muscular work and the cardiovascular demands of the diving response.
Why Low Carbohydrate Availability Is Not Automatically A Performance Strategy
Carbohydrates have become strangely controversial outside sports science. Depending on which corner of the internet you enter, they can be presented as essential athletic fuel or as something humans would apparently be better off almost completely avoiding. Elite sport is rarely served particularly well by nutritional ideology. The research on carbohydrate availability and conventional exercise performance is substantial. Muscle glycogen is used during physical activity, with utilization generally increasing as exercise intensity rises. Starting demanding exercise with adequate glycogen availability can support performance, while carbohydrate consumed after exercise contributes to replenishing glycogen for subsequent training.
Modern research has also made the picture more sophisticated than simply saying more carbohydrate is always better. Training with reduced carbohydrate availability can alter cellular signaling and may enhance some adaptations associated with endurance training. This has produced approaches sometimes described as "train low", where selected training sessions are deliberately performed with lower carbohydrate availability. The important word is selected. Low-carbohydrate availability is a training manipulation, not automatically a superior everyday nutritional state. If a session requires high quality or high intensity, inadequate carbohydrate availability can reduce the athlete's ability to perform the work that was actually prescribed. The theoretical metabolic benefit of training low becomes much less interesting if the athlete cannot complete the session properly.
Freedivers should be particularly careful with this logic because the sport already contains substantial physiological stress. Apnea training deliberately challenges oxygen availability. Depth adds pressure, changes in lung volume and the demands of equalization. Pool disciplines combine muscular work with progressive hypoxia and hypercapnia. Adding nutritional stress to physiological stress does not automatically produce a better adaptation. Sometimes it simply produces a worse session. More stress is not automatically better training, particularly when the athlete has not clearly defined what adaptation the additional stress is supposed to produce.
There is also a wider problem with focusing exclusively on the dive itself. A serious freediver may be doing depth training in the morning, strength work elsewhere in the week, pool dynamics, mobility sessions and general aerobic conditioning. Carbohydrate requirements should therefore reflect the complete training load rather than only the few minutes spent underwater. A diver who performs one relaxed depth session and then rests for two days has very different nutritional demands from an athlete training six days per week. This is why fixed carbohydrate prescriptions are often less useful than matching carbohydrate availability to training demand. Hard training days require more fuel. Lighter days may require less. Recovery days are different again. Nutrition should follow the training rather than forcing every training day into the same nutritional template.
Recovery Is Part Of The Carbohydrate Story
The conversation about carbohydrates often focuses on what happens before exercise, but for athletes training regularly, what happens afterwards may be just as important. Muscle glycogen used during training needs to be replenished. After exercise, carbohydrate intake provides glucose that can be used to rebuild those glycogen stores. When the next demanding session is relatively far away, total carbohydrate intake over the following day is generally more important than obsessing over an extremely narrow post-training window. When recovery time is short, timing becomes more relevant because the athlete has less time to restore what has been used.
Imagine an athlete completing a demanding morning session and then training again later that day, or a freediver in the middle of a training block with depth sessions on consecutive days combined with pool or strength work. The individual depth dive may not deplete glycogen in the same way as a marathon or a long cycling race, but the accumulated training load is what matters. This is where under-fueling can become difficult to recognize. The athlete does not necessarily wake up one morning completely unable to perform. Instead, training quality gradually changes. Legs feel heavier. Motivation decreases. Recovery becomes slower. Gym performance falls. A familiar workload feels unusually demanding. Relaxation can become harder because the athlete simply does not feel good.
The immediate assumption is often that more fitness is required. Sometimes more food is required.
Protein tends to dominate conversations about athletic recovery because its role in muscle repair and adaptation is easy to understand. Protein is important, but recovering from training is not simply a question of repairing muscle tissue. Fuel stores also need to be restored. A recovery meal containing adequate protein but almost no carbohydrate may address one part of recovery while ignoring another. For an athlete training frequently, both matter. This does not mean every freediver needs enormous bowls of pasta after every session. Nutritional intake should be proportional to the work performed and the work coming next. A recreational diver training twice per week does not need to eat like a professional endurance athlete, just as an athlete training several times across consecutive days should not necessarily eat like somebody spending most of the week sitting at a desk.
Carbohydrates are also not one single food category in any meaningful nutritional sense. A bowl of oats contains carbohydrates. So does a potato. So does fruit. So do lentils, rice, bread and pasta. A bottle of soft drink contains carbohydrate too. Treating all of these foods as nutritionally identical because they contain carbohydrate ignores everything else that comes with them. For most everyday meals, athletes can obtain carbohydrates from foods that also provide fiber, micronutrients and other useful components of a varied diet. Whole grains, fruit, vegetables, legumes, potatoes, rice and similar foods can all contribute carbohydrate while forming part of a broader nutritional pattern.
There are situations in sport where rapidly absorbed carbohydrate has a practical purpose. During prolonged endurance events, immediately around very demanding training, or when rapid glycogen restoration is required between sessions, easily digested carbohydrate can be useful precisely because it is easy to absorb. But a freediver does not need to turn every meal into sports nutrition. Most of the time, food should still look like food. There is also no reason for carbohydrate intake to look identical every day. A long, demanding training day may justify considerably more carbohydrate than a complete rest day. Someone doing a heavy strength session may have different needs from someone doing an easy technique session. The body responds to the work you actually ask it to perform, not to a fixed menu that ignores training load.
What This Means For Freedivers
The practical lesson is not that freedivers should start carbohydrate loading before every depth session. It is also not that fasting is bad, and it certainly is not that carbohydrates are some secret way to extend breath-hold time. The evidence does not support conclusions that simple. The useful lesson is that energy availability matters, glycogen matters and the nutritional strategy surrounding freediving should reflect the demands of the athlete rather than dietary fashion. If you prefer diving without food in your stomach, that can be perfectly compatible with adequate carbohydrate availability. Your glycogen stores were not created at breakfast that morning. What you ate during the previous day matters. If you are training hard on consecutive days, recovery nutrition becomes more important. If you combine freediving with strength training, pool work and aerobic conditioning, you need to fuel the entire training program rather than thinking only about the minutes spent on the line.
If you are deliberately experimenting with low-carbohydrate training, understand why you are doing it and what adaptation you are trying to create. Making a session harder is not automatically the same thing as making it better. If your training quality has been deteriorating while your workload keeps increasing, nutrition should be one of the variables you examine before deciding that you simply need to push harder. And if somebody tells you that one specific nutritional strategy is universally optimal for freediving, it is worth asking how much direct evidence actually exists. At the moment, freediving-specific nutrition research remains limited compared with the enormous literature available for endurance sports, strength training and conventional swimming. That means we should be particularly careful about turning plausible physiological ideas into rules.
Freediving is ultimately a sport of economy. We spend years trying to reduce unnecessary movement, unnecessary tension and unnecessary oxygen consumption. We refine technique because wasting energy underwater has consequences. But efficiency and under-fueling are not the same thing. The objective is not to give the body as little energy as possible. The objective is to give it what it needs and then teach it to use that energy exceptionally well.
A freediver descending into the blue may look almost motionless. Everything appears slow. The kicks are controlled. The heart rate falls. Movement becomes economical. From the outside, very little seems to be happening. Inside, the physiology is anything but still. ATP is being used and regenerated. Glycogen can contribute to muscular energy production. Blood glucose is being regulated. Oxygen availability is changing. The cardiovascular system is responding. The brain is making constant decisions about movement, pressure, discomfort and safety.
Holding your breath does not turn metabolism off. It makes efficient metabolism even more important.
That is why carbohydrates deserve a place in the freediving conversation, not as a miracle fuel and not as something to fear, but as one component of a much larger system. Train intelligently, recover properly and fuel according to the work you are asking your body to perform.
Then make every kick count.
Carbohydrates, Energy And Freediving
Author: Nick Pelios
Freedivers spend an enormous amount of time thinking about oxygen. We train to use less of it, tolerate lower levels of it and remain functional as it becomes progressively less available. We talk about relaxation, heart rate, the diving response, blood shift, hypoxia, carbon dioxide and efficiency. It makes sense. The defining characteristic of freediving is that we perform while voluntarily holding our breath. But oxygen is only part of the energy story. Your muscles still need energy to kick. Your diaphragm remains active. Your heart continues beating. Your nervous system is working constantly. During dynamic apnea, muscles continue contracting while oxygen availability progressively decreases. During a depth dive, the legs have to produce enough force to overcome positive buoyancy during the beginning of the descent and again during the increasingly demanding final part of the ascent. Between dives, the body has to recover and prepare to perform again. None of that happens for free.
Carbohydrates are one of the body's major sources of energy, and their role in athletic performance has been studied for more than a century. They are broken down into glucose, stored primarily as glycogen in the muscles and liver, and used to help regenerate ATP, the immediately usable form of energy required for muscular contraction and countless other cellular processes. For freedivers, however, the conversation needs some nuance. Freediving is not marathon running. It is not cycling, weightlifting or conventional swimming. We cannot simply take carbohydrate recommendations developed for other sports and assume that they apply perfectly to apnea. Research specifically examining carbohydrate intake and freediving performance remains limited. What we can do is understand the underlying physiology, look carefully at the evidence that does exist, and stop thinking about carbohydrates as either something athletes must constantly load or something serious freedivers should avoid. The more useful question is what job carbohydrates are actually doing and how that fits into the unusual demands of freediving.
From Food To ATP
When we eat carbohydrates, digestion eventually provides the body with glucose and other simple sugars that can enter metabolism. Some glucose is used immediately and some is stored, particularly as glycogen in skeletal muscle and the liver. Muscle glycogen acts as a local energy reserve. When a muscle needs energy, glycogen can be broken down and its glucose units fed into metabolic pathways that ultimately help regenerate ATP. Liver glycogen performs a somewhat different role, helping maintain blood glucose so that glucose remains available to tissues throughout the body. ATP is where all of this becomes relevant to movement. A muscle does not contract because you ate pasta the night before. It contracts because ATP provides usable chemical energy at the cellular level. The body therefore has to continually regenerate ATP throughout exercise.
Carbohydrate is particularly valuable because it can support ATP production through both aerobic and anaerobic pathways. When oxygen is sufficiently available, carbohydrate can be metabolized through pathways that ultimately involve oxidative phosphorylation. When ATP needs to be generated rapidly and oxygen availability cannot fully meet demand, carbohydrate can also contribute through glycolysis without requiring oxygen directly at that stage. That distinction matters because exercise intensity changes which fuels the body relies upon. As intensity increases, carbohydrate generally becomes increasingly important to working muscle. Fat is also an enormous energy reserve, and at lower exercise intensities it can contribute substantially to energy production. The body is not a machine that suddenly switches completely from one fuel to another. Fat and carbohydrate metabolism operate simultaneously, with their relative contributions changing according to intensity, duration, training status, diet and fuel availability.
This is one reason arguments about whether carbohydrates or fats are the "better" fuel tend to be less useful than they sound. Human metabolism uses both. The question is which substrate can best support the task being performed. Freediving makes that question particularly interesting because the objective is not simply to produce as much energy as possible. It is to produce the movement required while keeping the total metabolic cost as low as possible. A good freediver is economical. Watch an experienced athlete beside a beginner and the difference can be obvious. The experienced diver may cover the same distance with fewer unnecessary movements, better body position, cleaner kicks and less muscular tension. Both divers are producing energy, but one is spending it more intelligently. This is why technique is effectively part of freediving metabolism. Every unnecessary muscular contraction has an energetic cost. Tension has a cost. Poor streamlining has a cost because additional propulsion must compensate for additional resistance. An inefficient kick has a cost. Nutrition can provide fuel, but it cannot make inefficient movement efficient.
The Carbohydrate Question Gets More Complicated Underwater
If carbohydrates are an important exercise fuel, it would be easy to conclude that freedivers should simply consume more carbohydrates before diving. This is exactly where things become more complicated. A freediver does not necessarily want to begin a depth session with a large amount of food sitting in the stomach. A full stomach can interfere with comfort, diaphragm movement and the overall sensation of a deep dive. Digestion itself requires physiological activity. Many divers therefore develop very individual routines around meal size and timing before depth training. The fact that carbohydrate is important to energy metabolism does not mean a large carbohydrate-heavy meal immediately before getting on the line is automatically a good idea.
There is some direct freediving research showing why simplistic nutrition advice is difficult here. One small study examined eight divers performing a 30-metre breath-hold dive under two conditions. In one condition they dived three hours after a normal breakfast. In another, they followed a dietary intervention and then fasted overnight before the dive. During the fasting condition, the static phase incorporated into the dive was longer, blood lactate after surfacing was lower and arterial oxygen saturation was higher despite the longer dive. The researchers suggested that the metabolic and splanchnic conditions associated with fasting may have influenced the diving response. It is an interesting finding, but eight divers performing a particular experimental protocol is nowhere near enough evidence to tell freedivers that fasting improves performance, and it certainly is not evidence that carbohydrates should be avoided.
This distinction matters because there is a major difference between arriving at a depth session with an empty or relatively empty stomach and living or training with chronically low carbohydrate availability. There is also a difference between what feels good immediately before one dive and what supports an athlete across an entire week of training. A freediver might prefer to dive several hours after eating because the stomach feels comfortable. That does not mean the muscles need to begin the session with depleted glycogen. Glycogen stored from meals consumed many hours earlier, including meals from the previous day, remains available. Fueling does not necessarily mean eating immediately before the dive. The body has storage. That is the entire point of glycogen. A diver can therefore arrive at the boat without a heavy breakfast sitting in the stomach while still having adequate carbohydrate availability from their broader diet. These are not contradictory ideas.
Research in experienced breath-hold divers also suggests that glucose metabolism is actively involved during diving. One study involving experienced breath-hold divers measured blood glucose, insulin and catecholamines before and after repeated breath-hold dives and observed changes in glucose and hormonal responses following the diving session. The exact metabolic consequences of those changes are not yet sufficiently understood to translate them into a specific freediving nutrition protocol, but the broader point is useful. Apnea does not suspend normal energy metabolism. You may have stopped breathing, but your cells have not stopped working. The body still has to regulate fuel availability while simultaneously responding to hypoxia, carbon dioxide accumulation, muscular work and the cardiovascular demands of the diving response.
Why Low Carbohydrate Availability Is Not Automatically A Performance Strategy
Carbohydrates have become strangely controversial outside sports science. Depending on which corner of the internet you enter, they can be presented as essential athletic fuel or as something humans would apparently be better off almost completely avoiding. Elite sport is rarely served particularly well by nutritional ideology. The research on carbohydrate availability and conventional exercise performance is substantial. Muscle glycogen is used during physical activity, with utilization generally increasing as exercise intensity rises. Starting demanding exercise with adequate glycogen availability can support performance, while carbohydrate consumed after exercise contributes to replenishing glycogen for subsequent training.
Modern research has also made the picture more sophisticated than simply saying more carbohydrate is always better. Training with reduced carbohydrate availability can alter cellular signaling and may enhance some adaptations associated with endurance training. This has produced approaches sometimes described as "train low", where selected training sessions are deliberately performed with lower carbohydrate availability. The important word is selected. Low-carbohydrate availability is a training manipulation, not automatically a superior everyday nutritional state. If a session requires high quality or high intensity, inadequate carbohydrate availability can reduce the athlete's ability to perform the work that was actually prescribed. The theoretical metabolic benefit of training low becomes much less interesting if the athlete cannot complete the session properly.
Freedivers should be particularly careful with this logic because the sport already contains substantial physiological stress. Apnea training deliberately challenges oxygen availability. Depth adds pressure, changes in lung volume and the demands of equalization. Pool disciplines combine muscular work with progressive hypoxia and hypercapnia. Adding nutritional stress to physiological stress does not automatically produce a better adaptation. Sometimes it simply produces a worse session. More stress is not automatically better training, particularly when the athlete has not clearly defined what adaptation the additional stress is supposed to produce.
There is also a wider problem with focusing exclusively on the dive itself. A serious freediver may be doing depth training in the morning, strength work elsewhere in the week, pool dynamics, mobility sessions and general aerobic conditioning. Carbohydrate requirements should therefore reflect the complete training load rather than only the few minutes spent underwater. A diver who performs one relaxed depth session and then rests for two days has very different nutritional demands from an athlete training six days per week. This is why fixed carbohydrate prescriptions are often less useful than matching carbohydrate availability to training demand. Hard training days require more fuel. Lighter days may require less. Recovery days are different again. Nutrition should follow the training rather than forcing every training day into the same nutritional template.
Recovery Is Part Of The Carbohydrate Story
The conversation about carbohydrates often focuses on what happens before exercise, but for athletes training regularly, what happens afterwards may be just as important. Muscle glycogen used during training needs to be replenished. After exercise, carbohydrate intake provides glucose that can be used to rebuild those glycogen stores. When the next demanding session is relatively far away, total carbohydrate intake over the following day is generally more important than obsessing over an extremely narrow post-training window. When recovery time is short, timing becomes more relevant because the athlete has less time to restore what has been used.
Imagine an athlete completing a demanding morning session and then training again later that day, or a freediver in the middle of a training block with depth sessions on consecutive days combined with pool or strength work. The individual depth dive may not deplete glycogen in the same way as a marathon or a long cycling race, but the accumulated training load is what matters. This is where under-fueling can become difficult to recognize. The athlete does not necessarily wake up one morning completely unable to perform. Instead, training quality gradually changes. Legs feel heavier. Motivation decreases. Recovery becomes slower. Gym performance falls. A familiar workload feels unusually demanding. Relaxation can become harder because the athlete simply does not feel good.
The immediate assumption is often that more fitness is required. Sometimes more food is required.
Protein tends to dominate conversations about athletic recovery because its role in muscle repair and adaptation is easy to understand. Protein is important, but recovering from training is not simply a question of repairing muscle tissue. Fuel stores also need to be restored. A recovery meal containing adequate protein but almost no carbohydrate may address one part of recovery while ignoring another. For an athlete training frequently, both matter. This does not mean every freediver needs enormous bowls of pasta after every session. Nutritional intake should be proportional to the work performed and the work coming next. A recreational diver training twice per week does not need to eat like a professional endurance athlete, just as an athlete training several times across consecutive days should not necessarily eat like somebody spending most of the week sitting at a desk.
Carbohydrates are also not one single food category in any meaningful nutritional sense. A bowl of oats contains carbohydrates. So does a potato. So does fruit. So do lentils, rice, bread and pasta. A bottle of soft drink contains carbohydrate too. Treating all of these foods as nutritionally identical because they contain carbohydrate ignores everything else that comes with them. For most everyday meals, athletes can obtain carbohydrates from foods that also provide fiber, micronutrients and other useful components of a varied diet. Whole grains, fruit, vegetables, legumes, potatoes, rice and similar foods can all contribute carbohydrate while forming part of a broader nutritional pattern.
There are situations in sport where rapidly absorbed carbohydrate has a practical purpose. During prolonged endurance events, immediately around very demanding training, or when rapid glycogen restoration is required between sessions, easily digested carbohydrate can be useful precisely because it is easy to absorb. But a freediver does not need to turn every meal into sports nutrition. Most of the time, food should still look like food. There is also no reason for carbohydrate intake to look identical every day. A long, demanding training day may justify considerably more carbohydrate than a complete rest day. Someone doing a heavy strength session may have different needs from someone doing an easy technique session. The body responds to the work you actually ask it to perform, not to a fixed menu that ignores training load.
What This Means For Freedivers
The practical lesson is not that freedivers should start carbohydrate loading before every depth session. It is also not that fasting is bad, and it certainly is not that carbohydrates are some secret way to extend breath-hold time. The evidence does not support conclusions that simple. The useful lesson is that energy availability matters, glycogen matters and the nutritional strategy surrounding freediving should reflect the demands of the athlete rather than dietary fashion. If you prefer diving without food in your stomach, that can be perfectly compatible with adequate carbohydrate availability. Your glycogen stores were not created at breakfast that morning. What you ate during the previous day matters. If you are training hard on consecutive days, recovery nutrition becomes more important. If you combine freediving with strength training, pool work and aerobic conditioning, you need to fuel the entire training program rather than thinking only about the minutes spent on the line.
If you are deliberately experimenting with low-carbohydrate training, understand why you are doing it and what adaptation you are trying to create. Making a session harder is not automatically the same thing as making it better. If your training quality has been deteriorating while your workload keeps increasing, nutrition should be one of the variables you examine before deciding that you simply need to push harder. And if somebody tells you that one specific nutritional strategy is universally optimal for freediving, it is worth asking how much direct evidence actually exists. At the moment, freediving-specific nutrition research remains limited compared with the enormous literature available for endurance sports, strength training and conventional swimming. That means we should be particularly careful about turning plausible physiological ideas into rules.
Freediving is ultimately a sport of economy. We spend years trying to reduce unnecessary movement, unnecessary tension and unnecessary oxygen consumption. We refine technique because wasting energy underwater has consequences. But efficiency and under-fueling are not the same thing. The objective is not to give the body as little energy as possible. The objective is to give it what it needs and then teach it to use that energy exceptionally well.
A freediver descending into the blue may look almost motionless. Everything appears slow. The kicks are controlled. The heart rate falls. Movement becomes economical. From the outside, very little seems to be happening. Inside, the physiology is anything but still. ATP is being used and regenerated. Glycogen can contribute to muscular energy production. Blood glucose is being regulated. Oxygen availability is changing. The cardiovascular system is responding. The brain is making constant decisions about movement, pressure, discomfort and safety.
Holding your breath does not turn metabolism off. It makes efficient metabolism even more important.
That is why carbohydrates deserve a place in the freediving conversation, not as a miracle fuel and not as something to fear, but as one component of a much larger system. Train intelligently, recover properly and fuel according to the work you are asking your body to perform.
Then make every kick count.