Is being skinny better for swimming?

Swimming is a sport that requires strength, endurance, and technique. There has long been a perception that being skinny or lean gives swimmers an advantage in the water. But is this really true? Let’s take a closer look at how body composition impacts swimming performance.

The Advantages of Being Skinny for Swimming

There are a few potential advantages to being skinny or having a lean physique for swimming:

• Less drag in the water – Body fat and muscle mass create drag and resistance in the water. The skinnier you are, the less drag you’ll experience, allowing you to move through the water more efficiently.
• Easier body position – Skinny swimmers tend to find it easier to maintain proper streamlined body alignment and posture while swimming. More body fat can make it harder to keep the legs and hips high in the water.
• Less weight to move – There’s no getting around the fact that extra weight requires more effort to move through the water. The less you weigh, the lighter you’ll be in the water.

The primary advantage for skinny swimmers appears to be reduced drag and increased efficiency moving through the water. Full-body swimsuits and shaving are used to achieve similar effects. But being naturally lean can provide an edge.

The Disadvantages of Being Too Skinny

However, being extremely skinny or underweight does come with some disadvantages for swimmers:

• Reduced muscle mass – While some fat is good to lose, too little muscle mass reduces power and endurance.
• Lower energy levels – Very low body weight can result in insufficient fuel and lower energy levels during races and workouts.
• Overtraining risk – Skinny swimmers are at greater risk of overtraining, injury, and burnout without sufficient rest and nutrition.
• Poor body temperature regulation – Low body fat provides less insulation against cold pool water, raising hypothermia risk.

In short, an overly skinny physique reduces muscle power and endurance capacity. Some body fat provides insulation and energy reserves that skinny swimmers may lack.

The Ideal Swimmer’s Body Type

Rather than being extremely skinny, most experts agree the ideal swimmer’s body combines leanness and muscularity. Here are the key traits of the optimal swimmer’s physique:

• Low body fat – Body fat percentage around 10-15% for men and 15-22% for women allows leanness without compromising health.
• Muscular arms, shoulders, and back – Powerful upper body musculature provides strength for strokes.
• Strong core – A strong core stabilizes body position and provides power from the center of the body.
• Lean, tapered legs – Long, lean legs optimized for kicking with a minimum of drag.

This combination allows for power, endurance, and efficiency in the water. While being skinny provides some advantages, well-developed musculature and an athletic physique is ideal.

The Impact of Different Strokes

The importance of leanness versus power varies somewhat between swimming strokes:

• Freestyle – Leanness and drag reduction are most important for this stroke. Body position and surfacing also benefit from low body fat.
• Backstroke – Muscularity becomes somewhat more important for power generation. But leanness remains beneficial.
• Breaststroke – Power is crucial on this stroke, placing greater emphasis on muscle mass. Some upper body fat provides buoyancy.
• Butterfly – The most physically demanding stroke requires substantial upper body strength and power. A lean but muscular build is best.

So while leanness and low drag help all strokes, power becomes increasingly important from freestyle to breaststroke to butterfly. The ideal physique balances both.

Body Composition and Swim Performance

Let’s look at what the research says about how body composition impacts swim performance:

• A 2020 study found lower body fat had a small positive effect on 100m freestyle time in youth swimmers.
• Multiple studies have shown very low body fat can negatively impact performance in endurance swimming events.
• Higher muscle mass correlates with greater tethered swimming force and sprint performance in swimmers.
• But muscle mass must be balanced with flexibility – overly bulky musculature can increase drag.

The evidence confirms that leanness provides some benefit. But overly low levels of body fat or muscle mass can hinder different aspects of performance.

Body Composition of Elite Swimmers

The physiques of Olympic and elite swimmers further illustrate the ideal swimmer’s body type:

• Male swimmers have average body fat around 10-12%. Many have visibly muscular upper bodies and torsos.
• Female swimmers average approximately 17-22% body fat. They have athletic, shapely muscle definition.
• Underwater weighing shows swimmers have 20-25% less body fat than the general population.
• Elite swimmers have greater muscle mass, particularly in the shoulders and back.

In short, the lean and athletic physiques of top swimmers combine low body fat with solid muscular development.

Take-Home Message: Balance Leanness and Muscle

The evidence is clear that being extremely skinny or lean provides some advantages in swimming. Low body fat reduces drag in the water, supporting efficiency and faster times.

However, being underweight or lacking in muscle can hinder power, strength, and endurance. An overly skinny build also increases injury and overtraining risk.

Instead, swimmers should aim for a physique that combines leanness with muscular development. Losing excess body fat while building a strong upper body, core, and legs creates the optimal balance. Table 1 summarizes the key benefits of different body compositions:

Body Type	Advantages	Disadvantages
Skinny/Underweight	Low drag Efficient movement	Reduced power Lower endurance Higher injury risk
Muscular/Bulky	Powerful strokes High strength	Increased drag Slower starts/turns
Lean and Muscular	Efficient movement Powerful strokes Strength and endurance	Minimal disadvantages

Achieving an athletic, lean, and muscular physique provides the optimal combination of efficiency, power, and endurance for swimming performance.

Conclusion

Being extremely skinny or lean can provide some advantages in the water. But a muscular swimmer’s build balanced with leanness is ideal. Losing excess fat while building strength maximizes power, efficiency, and endurance.

The physiques of elite swimmers confirm that optimizing body composition, not simply being skinny, is key. A body fat percentage around 10-15% for men and 15-22% for women, combined with solid upper body musculature, provides the best platform for swim performance.