Swim training and HR insights
Most triathletes find the swim to be the hardest discpline to make and manage improvement in. It is super common for people to be one paced and to simply bash away doing the same thing over and over expecting a different result. Technique improvement is king but also how you approach a session with regard to pacing, recovery and effort has an effect on performance. When we bike or run we have no issue in following a set containing intervals but all too often we see people who swim the same pace in every swim. The data maybe isn't as granular and using averages is somewhat flawed but lets take a look at HR ( as the measure of effort). Wrist based measures can be and are flawed but they are consistently flawed in the pool. Lets illustrate it simply ( yes we could spend days compiling a study but years of observation tell us what we will find) 2 swimmers Beginner with Max HR of 190 and Threshold of 157 Recovery swim - Pace 1:59 mins per 100m, HR avg 139, peak 160 Proper swim speed - Pace 2mins per 100m, HR avg 135, peak 155 The sessions should produce faster pace and higher HR on the Speed set but they don't. Expeienced swimmer with Max HR of 190 and Threshold of 165 Recovery swim - Pace 1:48 per 100m, HR avg 127, peak 148 Ultimo speed swim - Pace 1:29 per 100m, Hr avg 135, peak 155 This athlete shows more like what we would expect - working harder and speed is up and HR is up. Key thing is the skill level allows the effort to vary without killing form. We now have the obvious fact that HR will always be lower when swimming vs running or biking. Why is that? There are 3 reasons 1. The water is a coolant so the heart doesn't need to pump blood as hard to cool us down 2. Buoyancy - the water is supporting our bodyweight so we aren't using as many muscle groups as actively 3. Horizontal position - the pressure required to pump fluids is less when not pumping against gravity so again less CV strain. We still have the capacity in the CV system so why can't so many people use it fully? So its in theory easier to swim from a CV perspective but the limiters are many - technique is one but pacing,effort and swim specific fitness are the others. If you swim one paced then you will be one paced forever. We have to vary the stimuli.