Heart Rate Variability

MickTup

Question for you coaches out there how more reliable is HRV than just taking your resting heart rate each morning to gauge recovery? Heart Rate Variability (HRV) new method to me of measuring recovery, a friend of mine says it's the most reliable method to measuring recovery . Apparently by measuring the gap between heart beats. If your body is well rested, working efficiently and free of stress, the variability will be high. If you are unwell, fatigued or have high levels of stress, your heart starts to regulate its beat and variability falls. So by tracking HRV on a daily basis, you can measure your level of recovery, or more importantly, your readiness to train again. You can do this by using a Bluetooth Heart Rate Monitor and a phone-app that measures HRV (Iithlete or sweetbeat) only on Iphone by the looks. Anybody no any other methods to take HRV? Andriod app etc.?

Team4Luke

Listening to your body, legs, mental state should be foremost pretty easy to feel whether you can or want to finish a session, resting hr is not any indication. Bear in mind there can be no training effect if you are recovered fully.

dw300

Lol, mines all over the place normally, I just thought that was crappy genetics, glad to hear this.

I've seen an Android app like this, but it involves you burning your finger off with the LED of your phone. It's actually pretty smart. You cover camera and flash with thumb, which gets illuminated (and hot), and the camera can tell thousands of shades of colour/tone and determine the start and end of a heartbeat as the blood pressure spikes and falls by the amount of light that's bouncing round in your thumb.

Problem is, if you have a low RHR then it just always tell you you are fresh and relaxed, since its not really meant for monitoring recovery in athletes (think its a stress measuring app.)

jonesy65

Ithlete has an Android app. You can either use a dongle plugged in to your phone that talks to a chest strap, or use a finger sensor. I think it's great - whenever I have fallen ill, Ithlete shows my HRV falling and tells me to go easy/ not train before I have any other symptoms. HRV reacts faster to day to day changes than resting HR, so it's a better measure of day to day health. Means you can train harder, as it tells you when you mustn't train or can go for it, picking up on all factors that affect your wellness on a given day: previous training, illness, sleep, stress etc.Their website is myithlete.com

Tom M

I'm not a coach, but I do teach physiology in a University, and use HRV as main part of my (nearly completed) PhD, so I have read more papers and spent more time doing measurements of this than I care to think.

The principle behind HRV relies on the fact that the output from the nerve that controls the heart under resting condtions is not constant, but does in fact vary with your breathing. As you breathe in, the activity that slows down the heart is reduced slightly, and therefore HR speeds up slightly. The technical term for this is respiratory sinus arrythmia. The greater the activity of this nerve (the cardiac vagus), the more this occurs, and therefore more variability is seen between sequential heartbeats, hence heart rate variability. Exercise training enhances the output of this nerve at rest, which is one reason why endurance athletes have low resting HR's, and also high levels of HRV. Those with poor HRV are at a higher risk of cardiac events like arrythmias and heart attacks, and it can be used as a clinical predictor of these. HRV is generally higher in younger people, and gradually diminishes as you age.

In relation to its usefulness as a tool to measure recovery, then like many of these things, I would say the answer basically is, it depends... From the technical side, there is no one single way to measure HRV, there's probably about 20 I could think of that are used in research. Whatever device you are using will essesntially record a series of heart beats and analyse the time differences between each one using a mathmatical transformation. Some transformations will tell you certain things better than others, so it very much depends on what one the particular programme uses, if you can even find out at all, as they might have their own (which I think Polar does for some of its HRMs). It will then give you an output of a number of some sort, but as to whether this is 'good' or 'bad' is a matter of interpretation not hard rules. You can't compare values between individuals with any usefulness, so comparing over time is better.

The other main caveat is that though HRV does mainly rely on the activity of the vagus (parasympathetic) nerve, there are a load of other things that can affect it too, which you have to be careful of. How deep/fast you breathe, the length of recording, eating/drinking beforehand, alcohol the day before, medications, menstrual cycle, caffeine, stress, and more will all contribute to HRV activity. In terms of the theory behind how it can be used as a marker of recovery/overtraining, it is mainly that this will show as increased sympathetic nervous system activity and increased levels of imflammatory compounds in the body that will reduce HRV.

So, and I will stop waffling on soon, in terms of using it solely as a tool to measure recovery, it is more shades of grey than black and white. If you do use it, then I would suggest you do so at the same time of day, and replicate the same conditions as closely as you can each time. First thing in the morning in bed before getting up would seem most ideal. How you actually feel is likely to be just as useful a way of telling. You would also need to look at changes over time for you as an individual, rather than one-off readings.

If you are interested, then it is a more sensitive measure than standard resting HR alone, but it would have to be used sensibly along with 'feel' I would suggest.