How to select between Red and Blue Zoomers fins:  Which model will be best for you?

The Red Zoomers fin is slightly stiffer ( 5 to 6%) than the Blue Zoomers fin.  There are several ways to decide which one will work best for you.   The choice depends on how  efficient your flutter kick is.  One of the most important benefits of Zoomers fins is being able to use your legs much more than you normally can when swimming.   You will go faster, your heart rate will be higher, you will get in better cardiovascular condition and you will have more fun swimming.

A Simple way to choose:  If you swim a fitness or lap swimming workout consisting of continuous laps, then the Blue fin is most often the best choice.    The Blue fin will let you work hard but will not prematurely fatigue your legs so you can use your legs throughout the workout.   If you have a poor kick, then the Red fin may  cause very rapid fatigue in your legs and then you end up dragging your legs for the remainder of your workout. 

The Best way to choose: Red vs. Blue based on the efficiency of the flutter kick:   If you make good to excellent forward progress when kicking flutter kick on a kick board, or if you are able to keep your flutter kick active continuously when swimming many laps of crawl stroke, then you have a good, efficient kick.   The Red Zoomers fin is the best choice. 

If you make very poor progress on a kick board, or when swimming crawl stroke, if you tend to drag your legs or use a two-beat kick, then your kick is not very efficient.   The Blue Zoomers fin is best for you.

What makes a kick good?  First, it has very little to do with intelligence, knowledge, or  coordination.  The difference between a good kick and a poor kick is primarily due to how far the feet flex forward.  Forward flexing of the foot is called plantar flexion.  

Example:  Watch swimmers swimming crawl stroke from the side view, under water.    Swimmer (A) with a good kick has feet which point straight back behind (the top of the foot will be parallel with the top of the water.   Swimmer (B) with poor plantar flexion, has feet which point down toward the bottom of the pool somewhat.  (See LEG PROPULSION:  for more explanation on transferring leg power to the water). 

The blade of the Zoomers fin is an extension of the foot.   When swimming crawl stroke, to get good propulsion from the Zoomers fin, when the foot is moving downward, you must push hard enough to bend the fin blade up past horizontal.   This allows the fin blade to slip forward on the water which, in turn,  pushes you forward.   Swimmer (A) with good plantar flexion  can bend the Red Zoomers fin far enough to get good propulsion for an amount of effort which is sustainable.   Swimmer (B) with poor plantar flexion must bend the fin blade much farther than Swimmer (A).   To get propulsion from the Red fin,   swimmer (B) must push so hard that the legs become fatigued EXTREMELY rapidly.     Swimmer (B) can get good propulsion from the slightly softer Blue Zoomers  fin for an amount of effort which can be sustained.