1. Swimming fights tiredness by improving oxygen intake and energy use in the body
As a common physical activity, swimming is a typically recommended exercise alongside many others, like biking, running, hiking, weightlifting, etc.
Each exercise is uniquely useful in improving health outcomes, as they all affect the manner in which the body engages the muscles and consumes oxygen for energy.
Understanding the effectiveness of swimming, however, comes from first learning what happens to the respiratory system of the body when working out.
Two stages of energy use, the aerobic phase and the anaerobic phase, occur when the body experiences a range of physical movement for an extended period of time.
During the aerobic (“with oxygen”) phase, an organism takes in enough oxygen to provide energy for muscles engaged in the exercise (14, 18, 20).
As a person continues to engage in the exercise and exert themselves, however, they gradually slip into the anaerobic (“without oxygen”) phase, where there is not enough oxygen intake from breathing alone to provide the muscles with energy.
The glycolysis process takes place during both phases, where glycogen (multiple branches of glucose stored in the body), gets broken down into the chemical compound, pyruvate.
Depending on the stage, pyruvate either enters the citric acid cycle to generate energy for muscle cells (in the aerobic phase), or it ferments and breaks down further to produce the chemical compound, lactate (in the anaerobic phase).
While lactate provides muscle cells with energy in the anaerobic phase, it also contributes to the feelings of tiredness, but not soreness, following a particularly intense workout, or working out for the first time after a long period of inactivity.
Therefore the amount of time it takes for someone working out to pass from the aerobic to anaerobic phase, as well as the time it takes to recover, determines their level of fitness.
In swimming and exercise in general, continued practice of physical activity increases the maximum oxygen capacity, or VO2, of an organism, allowing them more time to stay in the aerobic phase before entering the anaerobic phase.
While the effects of working out and increasing VO2 are typically positive, certain inherent traits such as the age, gender, and genetic makeup of the person working out, cause individuals to experience the benefits differently.
As researchers studied swimming as a means of improving physical fitness, they discovered that subjects who engaged in swimming classes or programs received some kind of boost to their VO2, regardless of their previous level of fitness.
During a two-to-three year longitudinal study conducted in Montreal, Canada, about 83 subjects engaged in a swimming program and demonstrated larger lung capacities than the control group, who did not engage in any exercise programs (16).
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Another study selected 69 college-aged males as test subjects to determine whether or not interval training (two days per week) could produce a change in VO2 while swimming.
There were significant gains in the maximal oxygen capacity for the study participants, with the greatest boost occurring after about 13 weeks of the program.
Other positive changes, such as effects on the heart, were connected to VO2, which will be discussed in the following section.
Continued participation in swimming can increase the maximum volume of oxygen in the lungs, which delays feelings of tiredness from the onset of the anaerobic phase.
These training effects not only aid oxygen capacity and efficiency but also affect the functioning of the heart and cardiovascular system as well.
While positive, however, the outcomes and overall effects of these improvements will be different between swimmers, meaning each swim journey will be unique and should not be points of comparison between them.
2. Swimming protects the heart and cardiovascular system
In addition to the benefits of a greater oxygen capacity and tiredness reduction, there is a direct connection to improvements in the cardiovascular system based on the improvements to the respiratory system.
During physical activity, the heart and the lungs work together to provide the rest of the body with energy via blood and oxygen, respectively; the conditions of both organs and the intensity of the workout, therefore, are helpful indicators of a person’s health (38, 49).
According to scientific research, the hardening and restriction of blood vessels (atherosclerosis) and the lining of the heart are indicators of low physical activity in most organisms.
These contribute to high blood pressure from atherosclerosis, while also influencing heart rates to be higher among inactive individuals in both resting and active conditions.
Additionally, there is a greater chance of a person becoming fatigued at a faster rate due to the larger burden on the system to efficiently pump blood throughout the body.
While researchers continue to explore the exact mechanisms, various forms of isometric exercise, including swimming, potentially counteract these negative effects.
As an isometric exercise, swimming requires the continuous lengthening (eccentric contraction) and shortening (concentric contraction) of the muscles to move through the water until an individual stops or grows tired, requiring the more efficient uptake of blood and oxygen to continue for longer stretches of time (14).
With enough exposure at a moderate intensity and duration devoted to swimming in a pool heated with a solar pool heater, subjects experienced ‘training effects,’ where the heart and other parts of the body greatly benefit.
In particular, the cardiovascular system experiences drops in blood pressure and heart rate (both resting and active), while increasing relaxation throughout the vascular system of an organism.
In both humans and rats, for example, studies found that engaging in swimming (or any physical activity) resulted in a lower resting heart rate than the relatively sedentary or inactive control groups in the general population.
More specifically, the rat subjects of one study experienced positive growth and adaptation in their heart muscles through tissue remodeling from muscle gene expression factors (52).
For the rat subjects of another study, they each experienced lower blood pressure, lower heart rate, and increased relaxation, at an optimal intensity equal to 3%, 4%, and 5% of their body weight (54).
One particular study on human subjects found that, along with a lower resting heart rate, the participants experienced overall changes to the “hemodynamics,”or the general functionality and distribution of blood, in the body (27).
These changes included an uptick in the supply of blood to the brain and a drop in wall shear stress, or strain on the blood vessel walls, possibly contributing to improved brain functionality and feelings of relaxation after swimming (56, 57).
Important to note in these findings, however, are the effects of an overly intense workout; placing too much stress on the body results in negative changes that can reverse the benefits, achieving an effect somewhat similar to a relatively sedentary lifestyle (9, 53, 48, 54).
Having a moderate regimen of swimming in typical, day-to-day life can minimize fatigue and improve the function of the cardiovascular system, potentially protecting against heart- and blood-related conditions, and other chronic conditions which will be discussed later.
3. Swimming provides social support and aids mental health and development
Along with physical benefits, swimming possibly also improves the mental health of individuals who participate in the sport.
Whether signed-up with a swim training program or provided with easy access to a local community pool, swimming itself is an incredibly social activity.
The support and engagement of family and friends is just as effective as that from a trainer, coach, and other teammates in competitive swimming.
The comfort of being around others and the effort required to successfully learn a new skill, can at least help ease the moods and circumstances contributing to some mental health conditions, such as anxiety and depression (8).
A study published in Psychosomatic Medicine followed about 100 college students and asked them to document their moods before enrolling in a semester-long swim class, and then afterwards when the program completed; they ranked themselves on the following criteria: Tension, Depression, Anger, Vigor, Fatigue, and Confusion (1).
When compared to the control group, the students who were swimmers reported a (not statistically) significant drop in feeling Tension, Depression, Anger, Vigor, and Confusion after completing the program; the exception, of course, was Fatigue since the subjects were not swimmers beforehand.
The controls who were not enrolled in the swimming courses, however, experienced very little positive or negative changes in their moods toward the end of the study.
Another study of a Glasgow, Scotland neighborhood explored the importance of swimming pool access from a far more leisurely perspective (4).
The simple presence of, and access to, the new local community pool was enough to relieve stress and isolation for those living nearby, even when visitors did not swim while there.
Interviewed subjects believed the easy set pool provided the local community with more things to do to engage the neighborhood, which generated improved interaction between neighbors overall.
The report also acknowledged, however, that the drops in stress and isolation could also possibly be connected to other, simultaneous socioeconomic improvements aside from the pool that would assist increased community engagement.
A third article published in the Journal of Sport and Social Issues studied swimming participation and its effects on social learning in swimmers, aged 9-12, in an Australian swim club (5).
As part of a “community of practice”, participants developed strong friendships due to the shared effort of swim training and the ability to communicate with other swimmers on a common topic.
The encouragement of coaches, the promise of meeting new people through competitions and swim meets, and social gatherings outside of swimming also motivated the children to remain with the club and push themselves to greater effort, even if they were not at a strictly competitive level.
From a sociological perspective, these strong bonds and associations are thought to be instrumental to, yet not solely responsible for, the foundations of personal and social identity in young children that will follow them into adulthood (46).
While the exact biological reasons behind the connection between swimming and improved mental health are still under review, many researchers and doctors often recommend swimming to provide helpful boosts in the long run.
Because swimming is a highly social and participatory sport, people report improvements in their moods, outlooks, and identities when they keep consistent swimming schedules over an extended period of time.
For young swimmers especially, they potentially develop their social skills, good habits, and attitudes around physical activity.
4. Learning to swim reduces the chance of drowning
The importance of knowing how to swim cannot be understated in its ability to save lives in some cases.
According to the World Health Organization (WHO), about 360,000 drowning deaths occur around the world every year (62).
The WHO names drowning the “third-leading cause of unintentional injury death worldwide”, with the most susceptible populations being children, men, and individuals with access to water.
Often times, these incidents occur through poor supervision, occupational hazards, reckless behavior, and limited or lacking safety measures, respectfully.
Along with public awareness and greater safety measures near bodies water, teaching people to swim, especially at younger ages, can greatly reduce the incidence of drowning.
While the effort to swim may not be able to account for every circumstance, like natural disasters or a situational loss of consciousness for example, it at least provides some opportunity for survival in other cases.
The ability to float, keep one’s head above water, move closer to shore or the edge of the pool, and keep oneself calm until help with a pool inflatable or rescue arrives can potentially make the ultimate difference (67).
Whether signing up to take classes at a community pool or being taught to swim from individuals with more experience, there are means to practice, develop, and acquire the necessary skills for becoming a relatively effective swimmer.
Even though swimming on its own cannot prevent most incidents of drowning and the circumstances surrounding them, having practice in the skill itself can still make some difference in the protection of a life.
5. The risk of contracting certain chronic illnesses drops with swimming exercise
Through the engagement and development of the cardiovascular and respiratory systems, swimming potentially lowers the risk of chronic illnesses later in life.
As individuals get older, they are more likely to experience chronic, or “noncommunicable” conditions that last or persist for longer than 3 consistent months.
According to the WHO, diseases like cancer, diabetes, arthritis, and hypertension are responsible for about 60% of deaths around the world, making them the leading cause of death (64).
Other contributing factors to the onset of chronic diseases included a combination of little-to-no medical pre-screenings, unequal infrastructure and healthcare financing and implementation, and the global spread of increasingly inactive lifestyles.
Since swimming only affects one of these contributing factors, keeping a consistent swim schedule lowers the risk of chronic disease, especially in higher-income neighborhoods.
Previously mentioned benefits of swimming (i.e. lowered resting heart rate, higher oxygen intake capacity, and improvements in mood and sociality) are instrumental in protecting against chronic diseases.
The positive adjustments to energy expenditure from the cardiovascular and respiratory system seemingly result in the tolerance of blood glucose in muscle cells, and possibly provide a counteractive effect toward diabetes (48, 58).
Researchers using rat subjects observed changes to metabolic biomarkers in their blood serum after continuous or interval swim training in the inclusion or exclusion of hesperidin; overall cholesterol, triglycerides and LDL-C (“bad” cholesterol) lowered, while there was an observed increase in HDL-C (“good” cholesterol).
Positive results like these were also present in a study using human subjects, particularly in older women who were mostly sedentary before the swim training began.
The rats also demonstrated an increased antioxidant capacity in their blood, meaning their bodies were more receptive to antioxidants that fight against the oxidative stress and free oxygen radicals responsible for some chronic illnesses, like cancer.
Similar implications for the changes in antioxidant capacity were present in a different research study on adolescent human subjects engaged in both endurance and high-intensity swim training (49).
Along with effective public health initiatives, physical activity in general and swimming in particular can potentially prevent or lower the risk of contracting chronic illness and noncommunicable diseases in the body.
The efficacy of swimming to protect against chronic conditions lies in its ability to indirectly target the biomarkers and oxidative stresses associated with each of the diseases.
6. Swimming supports a healthy and longer life
In aging, the general physiology of the body tends to deteriorate over time; the metabolism, the cardiovascular system, the respiratory system, and neuromuscular system experience declines in function at an accelerated rate (20).
Also when individuals age, they are more likely to limit their physical activity and adopt increasingly sedentary lifestyles through the pressures of work and/or taking care of their families (27).
Without some kind of regular, physical engagement in older age, people have otherwise shorter lifespans and increased mortality risk from disease susceptibility.
Swimming was found to have a 50% lower all-cause mortality risk in men when compared to individuals who ran, walked, or remained sedentary for the study, even when adjusting for age, body mass index (BMI), family history of CVD, behaviors, and other criteria (38).
Some studies have also found that even previously-sedentary, older individuals can receive improvements to their health through swim training.
For example, 44 women with a range of 50 to 70 years completed a swim study, where they experienced reductions in blood insulin and body fat, and an overall increase in their physical fitness (58) after swimming in an above ground pool regularly.
These adjustments occurred without any changes in the women’s respective diets, and were also more substantial when compared to the control group, which was only tasked with walking.
Other benefits of swimming for the elderly included the potential maintenance of balance, hand-eye coordination, and prevention of mobile disability, all of which are necessary for lowering the risk and rate of recovery from physical injury in later years (36, 37).
An additional study discovered that, despite the accelerated onset of aging and performance loss after the age of 70, swimming still was, and continues to be, a viable exercise of choice for individuals as old as 90, when provided with training accommodated to their needs.
While most physical activity already correlates to a healthier lifestyle in general, swimming can contribute certain advantages that can be more beneficial when compared to other forms of exercise.
Whether starting at a younger age or taking up the sport in later years, engaging in swimming is useful for maintaining healthful habits and delaying the onset of aging and its symptoms over time.
7. As a low-impact exercise, swimming causes less overall damage to muscles and joints
While many doctors recommend physical activity in general, certain members of the population may not readily participate, concerned with the effect some exercises will have on their bodies.
Though still potentially beneficial, activities that include jumping or running create strain on the joints and muscles, which can lead to difficulties in movement, chronic pain, and increased risk of injury as active or athletic individuals age (12,13).
Additionally, people who just start out, are pregnant, are overweight, or who have already experienced considerable injury to their joints or muscles may have difficulty sustaining these exercises for extended periods of time at higher intensities.
In running or jumping, at least one foot bearing the weight of the body comes in contact with the ground after each foot elevates; the amount of pressure from these constant impacts is then absorbed in the muscles and distributed throughout the legs, causing pain in cases when proper technique is not used (66).
With swimming, however, participants actively keep themselves in constant motion to stay afloat in water, rarely coming in contact with any surfaces capable of producing forces similar to those in running or jumping.
The effect of gravity on an individual in a body of water also gets displaced along the water surface, resulting in the property of buoyancy that bears the weight of the swimmer and also prevents further harm to the joints and muscles overall (65).
When compared to running and walking, swimming also has a lesser effect on bone mineral density than they do, demonstrating the lack of similar strain on the body, although this possibly disputes other claims that swimming delays the stages of osteoporosis (13, 21, 55).
If swimming at low to moderate intensities, individuals can potentially avoid the harmful effects of an overly-strenuous workout, while still receiving the other benefits associated with swimming.
With its low-impact attributes, swimming may be a reasonable exercise for people trying to protect the movement and function of their joints from new or continued strain from impact damage.
8. A correlation exists between swimming and an overall decrease in body fat percentage
For weight loss goals, whether through personal desire or medical recommendation, swimming may result in an overall decrease in body fat percentage.
Generally, the global increase of sedentary lifestyles and the continued consumption of high-calorie foods and beverages are several contributing factors resulting in heavier individuals.
While size and appearance alone are not accurate metrics for health status, heaviness associated with inactivity still comes with previously mentioned harms to health: higher resting heart rates and other cardiovascular conditions, increased risk for contracting chronic illness, labored breathing, and persistent feelings of tiredness regardless of exercise intensity (58).
Additionally, a higher proportion of adipose or fatty tissue is associated with an increased risk of metabolic diseases from the disproportional presence of lipids, such as triglycerides and total cholesterol (51).
Luckily, swimming is a gentle, more useful means of incorporating physical activity without the risk of similar injury or strain as found in high-impact sports. Of course, for those who want to increase the physical intensity in the water, there are alternatives such as a water trampoline.
One previously mentioned study documented the decrease in body fat percentages for each of the participants; when compared to their baseline measurements, their arms, legs, whole body, and trunk measurements experienced a decrease in body fat after 8 weeks of swim training.
This downward trend even continued 4 weeks after the training ended, suggesting that the swimming intervention interrupted processes responsible for overweight statuses in humans.
Another study recorded body weight differences between swimmers and walkers who did not alter their respective dietary intakes; observed were smaller waist girths and lower calves among swimmers when compared to walkers, along with a lower body weight and BMI (58).
Rat test subjects who swim trained for 4 weeks did not experience significant losses in body weight, but were at least observed with a consistent body weight, suggesting swimming still maintained body weight and halted the trend of significant weight gain over time (51).
While the outcome may not be similar for everyone, swimming affords some assistance in providing protections against continued weight gain, all while lessening the potential stress and strain of higher-impact, higher intensity physical activities.
Swimming is a valuable life-saving adaptation and skill to learn.
While any form of physical activity is markedly better than a sedentary lifestyle, swimming may be an easier choice for individuals at the start or in the middle of their respective fitness journeys.
Research supports that swimming is potentially less stressful on the body than high-impact exercises, increases oxygen capacity, improves cardiovascular function, helps protect against chronic illness, delays the effects of aging, and aids body weight regulation for its participants.
The social support and community one gains through swimming is also a great motivator for its participants, who are encouraged to maintain and continue its practice as they age, regardless of whether or not they do so for competitive purposes.
5 Tips to Help You Swim Better
As swimming is an isometric exercise, its purpose is to maintain movement, speed, and flotation in a body of water.
Swimmers must use their arms and legs to propel themselves against the forces of gravity and drag in water while controlling their breathing, an endeavor that requires training or practice with an experienced swimmer just to gain basic proficiency.
Here are some tips to consider if just starting out or if in need of adjustments to potentially improve power or speed.
Please take caution, however, as the effectiveness of these tips depends on personal skill level and the assurance of a more advanced swimmer for constructive feedback.
1. Learn to synch stroke movements for better control and speed
After a 30-weeklong training session, the participants of a swim study experienced positive, yet variable, improvements to their respective velocity and finish times, practicing the front crawl (freestyle) and backstroke methods (24).
The swimmers first worked on their kicks, before adjusting to synchronize their kicking with their breath cycle; following this, they then trained to synch and include single arm strokes before moving on to complete full strokes using all four limbs; afterwards, they made minor adjustments to the angle and speed of their arm movements.
The gradual addition of each movement possibly allowed the swimmers to adjust their stroke coordination and determine personally comfortable intensities, as well as reevaluate their previous techniques for necessary changes to improve their speeds (43).
Under the guidance of a trained professional, this makes for a good foundation for beginning swimmers, but can also be an effective strategy for the more intermediate and advanced swimmers among them.
2. Practice proper alignment and depth for each stroke
Because every swimmer must contend with multiple forces to move in a body of water, keeping a streamlined form while swimming is incredibly important for developing speed.
Aside from gravity, velocity, and buoyancy and their effects, drag and lift also determine how quickly one can propel themselves through water (42, 65).
Drag affects the flow of water as it passes over the swimmer, subtly disrupting the flow due to the generated friction between the surface of the water and the surface area of the swimmer.
The smaller, narrower, and more-balanced a swimmer makes themselves, the more they reduce the amount of surface area the water comes in contact with, affecting drag by producing a more streamlined flow between the swimmer and the water.
To address this, one study suggests keeping the head aligned with the rest of the body through every stroke, using the head as a focal point for the legs to maintain a leveled shape in the water (28).
The same study also recommends keeping the body at a depth of approximately 0.3 meters from the water surface, noting that swimming at shallower depths can break the surface and create waves, which are also sources of drag (28).
In this way, a swimmer can pass through water much faster and more efficiently using less energy to limit the forces slowing them down.
3. Practice improving posture inside and outside the water to avoid strain and increase power
A necessary component for maintaining proper alignment while swimming also lies in having consistently correct posture outside of practice and training.
The continued rise of sedentary lifestyles means more opportunities for the body to have uneven posture, as the muscles of the neck and back become weakened by longer sitting hours and unusual angling of the head when using technology.
If someone is too familiar with slouching in their daily lives, the unevenness in the shoulders and back can affect their strokes for a slower and slightly more uncomfortable experience.
Along with interrupting the streamline during a swim stroke and creating more drag, bad posture increases the potential for injury in the back and shoulders, leading to longer, unwanted recovery intervals over time (22).
A swimmer would also experience a limited range of motion and power in their stroke if hunched over, being unable to move efficiently and generating unnecessary stress when attempting to maintain a similar rate of power.
While strain in the shoulders and back is fairly common in swimming, well-defined posture can still potentially reduce the risk and occurrence of more severe injuries.
Some methods for improving posture include sleeping on one’s back rather than on the sides or stomach, sitting up straight in a chair with both feet flat on the floor, and adjusting swim technique with the help of a more advanced coach to improve both motion and power.
4. Try tethered swimming to gradually relieve feelings of tiredness and quickly increase maximal oxygen capacity
As a form of resistance training, tethered swimming allows individuals to control the intensity of their workout.
In tethered swimming, the swimmers attach themselves to one end of a pool with a tension-resistant, elastic cord, where they then must swim hard enough to stay afloat and maintain steady motion.
The cord is long enough to keep the swimmer away from walls, and holds different tensions depending on the type of cord used.
According to a research study analyzing the effectiveness of tethered swimming, it supposedly helps delay the anaerobic threshold of participants over time, meaning the swimmer can eventually swim for longer periods of time before tiring.
Tethered swimming seemingly generates anaerobic effects similar to untethered swimming, but in a shorter span of time, regardless of the intensity used between each technique.
Consistently scheduled use of tethered swimming pushes the body to familiarize itself with the anaerobic threshold and increase the maximal oxygen capacity in response.
The method can also simply provide a useful challenge to break up the monotony of training and swimming laps in an indoor pool with a pool cleaner.
The paper does note, however, that tethered swimming is not useful for all experience levels, recommending instead that relatively inexperienced swimmers should be cautious, or consult a more advanced swimmer, if they are interested in its use.
5. Keep a consistent swim schedule when practicing/training
Preserving a few positive changes from swimming, like the improvements to maximum oxygen capacity and heart functionality, requires consistently scheduled exercise.
Regardless of the physical activity one chooses, studies claim the body can return to a non-athletic state following a lack of exercise after two weeks, even losing the increases to its maximal oxygen capacity.
As was mentioned before, however, this should not amount to over-doing it; the wear and tear on an overactive body can also be just as detrimental as a sedentary lifestyle in the long run (48, 54).
Research points to balance in the form of endurance exercise, with it being slightly more effective than workouts of high-intensity for predicting positive exercise outcomes for swimmers (53).
This schedule should also include reasonable rest periods between moments inside and outside the water, allowing the body enough time to heal and overcome fatigue before the next opportunity arises.
Holding oneself accountable is also generally accepted for most activities, as it keeps participants engaged and motivated, and prevents the loss of skill over time without regular practice.