Stroke Rate & Stroke Length in OW

"better swimmers have a smaller max/min variation in velocity than swimmers that are slower And this is the key. To measure the amount of drag on an object in a fluid over time (or distance) you can not simply take the distance and divide it by the time. That works only when there are no drag forces involved. If you divide the distance by the time you do get an average speed but that is a different thing Specifically, drag in a fluid is proportional to the square of the velocity and, more importantly, the power needed to push an object through a fluid increases as the cube of the velocity. Thus even small fluctuations in speed can significantly increase the amount of power needed to cover a specific distance. Take 2 swimmers who swim a length of the pool: one holds a constant speed, while the other speeds up and slows down. If they both reach the other end of the pool at the same time, the one with the fluctuations in speed had to generate substantially more power than the swimmer who maintained a steady speed. We all know this from our own experience. We also know that any reduction in drag forces on the body reduces the power requirements necessary to maintain a constant speed. However, an analysis of the physics involves shows that simply gliding in a non-propulsive phase of your stroke only increases the total amount of power you need to maintain an average speed. From a pure layman's point of view, it appears that to maintain a specific speed and lower your stroke rate, you must do one or both of the following. First, you must have a strong enough kick to maintain a propulsive force during your glide, sufficient to maintain a constant speed. If your glide position is more hydrodynamical efficient, then the total amount of propulsive force required may be less, but if your arms are not generating the force during the glide then the legs must. (10 X 100 yd kick on the minute anyone?) Simply gliding in a streamlined position will only increase your total power requirements over time due to the relationship of speed to power as noted above. In the alternative, you can improve your streamlining during the entire time you are swimming, but you must continue to apply a constant force. Improving streamlining during the entire stroke cycle similarly lowers the total amount of power required to maintain a constant speed. Once again, simply gliding will only hurt you. One thing that I might add, is that the analysis of a deformable body (a swimmer) in a fluid is complex, and when you ignore the physiological issues that come in play, any such analysis is an oversimplification and subject to scrutiny. So which of the 2 options (kick more while gliding or better streamlining while swimming) require less power and presumably less energy of the swimmer? This is an entirely different question that requires a further analysis of the physiology of a swimmer, which I believe is more complex than the physics involved.

"better swimmers have a smaller max/min variation in velocity than swimmers that are slower And this is the key. To measure the amount of drag on an object in a fluid over time (or distance) you can not simply take the distance and divide it by the time. That works only when there are no drag forces involved. If you divide the distance by the time you do get an average speed but that is a different thing Specifically, drag in a fluid is proportional to the square of the velocity and, more importantly, the power needed to push an object through a fluid increases as the cube of the velocity. Thus even small fluctuations in speed can significantly increase the amount of power needed to cover a specific distance. Take 2 swimmers who swim a length of the pool: one holds a constant speed, while the other speeds up and slows down. If they both reach the other end of the pool at the same time, the one with the fluctuations in speed had to generate substantially more power than the swimmer who maintained a steady speed. We all know this from our own experience. We also know that any reduction in drag forces on the body reduces the power requirements necessary to maintain a constant speed. However, an analysis of the physics involves shows that simply gliding in a non-propulsive phase of your stroke only increases the total amount of power you need to maintain an average speed. From a pure layman's point of view, it appears that to maintain a specific speed and lower your stroke rate, you must do one or both of the following. First, you must have a strong enough kick to maintain a propulsive force during your glide, sufficient to maintain a constant speed. If your glide position is more hydrodynamical efficient, then the total amount of propulsive force required may be less, but if your arms are not generating the force during the glide then the legs must. (10 X 100 yd kick on the minute anyone?) Simply gliding in a streamlined position will only increase your total power requirements over time due to the relationship of speed to power as noted above. In the alternative, you can improve your streamlining during the entire time you are swimming, but you must continue to apply a constant force. Improving streamlining during the entire stroke cycle similarly lowers the total amount of power required to maintain a constant speed. Once again, simply gliding will only hurt you. One thing that I might add, is that the analysis of a deformable body (a swimmer) in a fluid is complex, and when you ignore the physiological issues that come in play, any such analysis is an oversimplification and subject to scrutiny. So which of the 2 options (kick more while gliding or better streamlining while swimming) require less power and presumably less energy of the swimmer? This is an entirely different question that requires a further analysis of the physiology of a swimmer, which I believe is more complex than the physics involved.