Next to knowing your swim times in a set like swimming 10x100's a swimmer should know his/her heart rate. By knowing your heart rate you will be able to know your training intensity and spot changes in your overall physical condition. In training one should know the four categories of heart-rate measurement:
1, Resting Heart Rate
2. Maximum Heart Rate
3. Submaximal Heart Rate
4. Recovery Heart Rate
I know this seems like a lot to know. And for someone like myself who hates math and can't figure out intervals in swimming 75's this is going to be tough for me. Does Speedo make an underwater calculator? I remember in age group swimming our coach would have us measure our heart rates. It's been so long that I don't remember anything more than putting two fingers to my neck counting my heart beats for 6 seconds and multiply that by 10. But as I've been reading this past week I keep stumbling upon using the heart rate as a gauge of effort. In this post will try to simplify How To Use Heart Rate To Gauge Swimming.
1. Resting Heart Rate - For swimmers in training a resting heart beat should be between 30-70 beats per minute BPM as opposed to a non=trained swimmer who will have 60-80 BPM. For new swimmers as your training starts off the BPM will decrease in the first few weeks of training. After that the swimmers resting heart rate will stabilize and not change. Of course outside influences such as time of day, earlier same day activity like running or waking and of course mental/emmotional influences But let's just say in theory we all have our own resting heart rate on an average day.
The method that I grew up to measure my heart beat of taking it for 6 seconds and multiply that by 10 is not accurate enough. I read that one should take the heart rate for at least 30 if not the full 60 seconds. Also, to get a Resting Heart Beat you can either take it when you wake up in the morning or right before training. The morning thing might not work for me as I'm absent minded enough at 5am never mind asking me to remember to take my heart rate. I'm going to put a post it on my computer monitor to take my heart rate tomorrow morning. I don't do anything without going to my computer first in the morning.
2. Maximum Heart Rates - If you are swimming at your maximum heart rate then you are swimming faster than your threshold speeds, but that doesn't mead you are swimming your fastest. To determine your maximum heart rate you will need to do some math. Don't worry even I can handle this low level of math so you can too. The average maximum heart rate for athletes is 175-220 which although won't change with training it will decline with age. A few more average maximum heart rates for us Masters athletes are for our adult years our MHR should be 180-200 while more senior athletes should be below 180. The most simply way to find your maximum heart rate is to take the 220 BPM and minus your age. So for me I'd take 220 and minus 39 giving me a MHR of 181. But that 181 is my athletic maximum heart rate and not my swimming maximum heart rate. Why? Swimmers maximum heart rates are 10 to 15 BPM slower. Two theories on why this is are that when swimming we are vertical making it easier for the heart to pump blood and secondly the water reduces body temperature which reduces stress on the heart. If you swim in the West Hollywood Pool in winter time then it's a whole other story. Another prefect example on why swimming in a heated pool is not good for you. Take that Noodlers!
Swimmers and anyone doing any exercise should be counting their hear rates after sever maximum efforts over a series of days to get the best determination of one's maximum heart rate. The point of knowing your maximum heart rate? Well if you continue to work out at maximum heart rate about 8 to 15 minutes into doing so ones lactic acid will accumulate rapidly in the muscles causing one to slow down considerably. Knowing your heart rate means you can swim a better and longer workout.
3. Submaximal Heart Rates - Now comes the math. Swimming with a heart rate monitor is the best if still flawed way to get one's submaximal heart rate. Let's break this down a simply as possible by following the below as a guide:
120-140 bpm - Low intensity
140-160 bpm - Moderate intensity
160-180 bpm - High-intensity endurance training. This is swimming at your threshold.
180-Maximum bpm - Very high intensity training. Swimming at overload endurance speed.
Now once again these numbers are guides and everyone's definition of low, moderate, high and very high intensity is different. That is why it is important that you take your heart rate over several days. Ready for some math? A more accurate way of using heart rates in swimming is using the Karvonen's Heart-Rate Reserve Formula. I'm not going to go into the background you can google it. What the HHR does is allow one to train at a certain % of one's Maximum Heart Rate. Being a swimmer we are always hearing the coach yell at us to go 80% all out in this 100 then bring it back down to 50% for the following 50 then 90% for the 25 or something similar to that. It's always been a mystery to me how I was suppose to now what 80% of my speed was. I just swam. But by knowing your Maximum Heart Rate you can now to some degree train more efficiently. So grab your calculator as this is real math:
Let's say you want to train at 80% and your Resting Heart Rate is 40 BPM and your Maximum Heart Rate is 185 BPM:
HRR = HR rest + 0.80 + (HR Max - HR Rest)
HRR = 40 + 0.80 + (185 - 40)
HRR = 156 BPM
So 156 round be your heart rate for swimming at 80% effort. Besides the HRR you can also find out your submaximal heart rate using other formulas such as MHR- and & MHR but I'll allow you to look up more information on those two methods.
4. Recovery Heart Rates - This is as simple as stating that it's the time required for the heart rates to return to resting levels. Now this isn't to say one should stop, sit around a few minutes and take his/her heart rate. One should do an active recovery then measure the heart rate. One guide suggests taking the heart rate 30-45 seconds after the hard swimming has stopped. So they I see that as meaning after I swam my last 100 this morning I should have swam a 25 then taken my pulse to get my Recovery Heat Rate.
Knowing your heart rate is key to training properly but it cannot predict your anaerobic threshold speed accurately. But, and this is a big but, well-trained athletes heart rates within 10-20 bpm of maximum heart rate may be accurate enough to monitor your threshold endurance training. With that said ir you cannot maintain a training speed that produces a heart rate 10-20 BPM below your MHR than you need to slow it down.
With all of this it should be done with a coach advising you. Everyone is different so please consult someone before you follow the above as the scripture. I'm breaking down a very complicated section or two from two books into a simple guide to measuring your heart beat and using it in training.
Sources for this post: The New Science of Swimming by James E. Counsilman and Swimming Fastest by Ernest W. Maglischo.


