Swim-Specific Resistance Training: A Systematic Review
Link to research paper
What are the benefits of resistance training for endurance athletes?
Resistance training (aka “strength training”) is a highly effective method of improving endurance sport performance. There is more and more evidence emerging that demonstrates the benefits of resistance training for endurance athletes, particularly for runners. However, resistance training can benefit all endurance athletes in multiple ways. First, appropriately progressed and prescribed resistance training can improve overall muscular strength and resiliency. This is likely to yield a reduced risk of injury as one improves their body’s overall resistance to injury through an improved ability to tolerate higher demands and greater stressors (i.e., repetitive movements accomplished through endurance sport). Second, resistance training (particularly plyometrics and explosive movements) can improve mechanical efficiency, and this is particularly the case for runners who utilize the stretch-shortening cycle unlike other endurance athletes, such as cyclists and swimmers (although swimmers do utilize this mechanical process when jumping off the blocks and pushing off of walls after flip turns).
These are just a few of the primary benefits of resistance training, but like I have mentioned, some of these benefits may be more apparent in runners when compared to cyclists and swimmers. In swimming, however, resistance training certainly still holds value as it relates to improving strength and reducing risk of injury. A stronger athlete is most often likely to be a better athlete in general, but in swimming, what kind of resistance training is best? One main principle of resistance training is referred to as “specificity”, which basically states that an athlete will adapt to the specific demands that resistance training imposes. For example, if one does a free weight bicep curls, the adaptations experienced from that movement are going to be radically different than another athletes experiences from performing explosive box jumps. There are many different forms of resistance training out there, including isotonic exercises (movements involving concentric and eccentric actions), isometric exercises (static movements involving muscle contraction without concentric or eccentric actions), isokinetic exercises (concentric and eccentric actions performed on a specific machine that creates resistance against a set speed/velocity of movement), and inertial exercises (i.e., exercises performed against the resistance of a flywheel).
Which one of these forms of resistance training is best for swimming? Swimming is indeed a very unique sport when compared to land-based sports like cycling and running as it is performed completely immersed in water. Water resistance and buoyant forces experienced in the water are unique from air resistance and gravitational forces experienced on land. The study described here in helps shed some light on what forms of resistance training have the most support for eliciting benefits for swimmers.
What did the researchers study?
Researchers in this study performed a systematic review of published peer-reviewed research to determine which type of swim-specific resistance training is most beneficial to enhance swimming performance. Systematic reviews are one of the highest forms of evidence as they are a summary of peer-reviewed papers describing individual studies. For their review, the researchers found 25 published studies that met their predetermined inclusion criteria, and from these 25 studies described what the research tends to suggest regarding swim-specific resistance training.
What are the major findings?
Researchers in this study made the following THREE conclusions:
1. In-water swim-specific resistance training (e.g., training in-water with bands) is an effective method to improve swim strength and performance.
2. Inertial training (i.e., resistance training with special machines that use flywheels to provide resistance) is an effective method to improve swim strength and performance.
3. The previous two types of resistance training are likely more effective than other land-based, swim specific resistance training movements (e.g., traditional free weight exercises or other swim-specific free weight or body weight movements) for improving swim strength and performance.
What do these findings mean to YOU as an endurance athlete or coach?
Take-home messages from this research study should be as follows:
1. The principle of specificity is incredibly important when it comes to resistance training for a sport as not all strength training modalities will impose the same benefits from one type of athlete/sport to another.
2. In swimmers, traditional free weight resistance training exercises are likely of benefit for developing basic strength, power, etc. However, to get more specific with resistance training, in-water swim-specific resistance training (through the use of band-resisted or counterweight-resisted swimming) as well as inertial training are likely to have superior transfer to swim strength and performance when compared to more traditional free weight and body weight exercises.
Swimming imposes unique demands on the body, primarily due to the unique forces imposed on an athlete while immersed in water (drag, lift, gravity, and buoyancy). Although traditional free weight and body weight resistance training exercises are great for developing basic strength, power, endurance, etc., the more specific to swimming a coach can make resistance training and the forces an athlete has to overcome in said resistance training movements, the more likely it will transfer directly to swim-specific strength and performance. This may be why performing resistance exercises in the water while actually swimming as well as inertial training may be more effective than other forms of resistance training for the swimmer.
Triathletes may benefit from a combination of traditional resistance training exercises as well as these other forms of resistance training as they participate in swimming, cycling, and running. Single-sport, dry-land athletes like cyclists and runners may benefit mostly from traditional free weight exercises (e.g., free weights, body weight, plyometrics, etc.). Finally, single-sport swimmers will benefit from a foundation of strength developed through traditional free weight and body weight exercises, but as the athlete advances, more swim-specific resistance training exercises should be incorporated to improve swim-specific strength and performance.
Now that you have read this month’s “Science Post”, go ahead and put your newfound knowledge to the test and take this short quiz. You will also have the opportunity to think about how this knowledge can be incorporated onto your practice as an athlete or a coach: https://forms.gle/ijwP34CH6Jzgbc3m7
Happy training and racing!
-Ryan Eckert, MS, CSCS