Monitoring your training

Chances are that if you are here, you are someone highly motivated to train. Perhaps someone who approaches every session with the goal of coming out of it better. After all, that is the point of training: to perform better. Time to state the obvious: in wanting to do a lot, we are never far from doing too much. Even with a meticulously crafted training plan, our body may not be able to keep up the pace. Notably because it is hard to quantify the impact of everyday stress on our fitness level. Fortunately, means of detection exist, and we are going to present here the easiest ones to put into practice.

Overtraining

As soon as we seek to maximize our performance and take advantage of our body's full potential, we edge dangerously close to the line between optimal training load and overtraining. It is essential to stay below the optimum (and to be as close to it as possible), without leaping into the hell of too much is too much. Undertrained, it is always possible to dig into your mental resources to give the little extra needed. Overtrained, no amount of willpower will win you any performance, since the body is no longer able to deliver it. More bluntly, overtraining is the process of destroying the body. The organism can no longer keep up the rhythm. It then reduces our performance to signal that something is wrong, and if we do not listen to it, either performance keeps dropping, or a fatigue injury appears, or worse, hormonal disruptions. Overtraining is all the more dangerous in that it generally takes time to detect, and even longer to get out of. Usually with a complete break of several weeks. The first symptoms of overtraining are recurring fatigue during work sessions. We no longer have the same pep and the same drive at the start, and we feel empty during the effort. Heart rate is also higher than usual during exercise and at rest. If nothing is done, other more serious symptoms can appear:

In such cases, you must stop training right away and consult a healthcare professional.

First safeguard: listen to your heart

Resting heart rate

The first observation tool is to measure your resting heart rate (RHR) daily. It is the nominal rate when you are motionless. This rate gives a picture of the state of freshness we are in at the time of measurement. To measure RHR, simply lie down doing nothing, then start a 5-minute recording. The average value (excluding spikes) is RHR. This measurement must be repeated every day under the same conditions. If that is not the case, the new condition must be logged (a few beers down the hatch, for example). If RHR increases by more than 10% compared with the monthly average, under identical conditions, it means the body is compensating for a heavy training load. Heart rate variability, HRV, completes this cardiac picture. To keep it short, HRV is the time between cardiac peaks, without being the period of the heart rate. To measure it, the most effective way is to do a full electrocardiogram, which can be complicated if you do not have access to an available medical machine. Another method is to use a high-end POLAR strap and watch, capable of giving fairly precisely the same information after a recording of several minutes.

Heart rate variability

Heart rate variability (VFC in French, HRV in English) is the time needed between two heartbeats. It is the instantaneous period between two cardiac pulses, whereas heart rate is based on an average period. This instantaneous period is often called the R-R interval, whose value is expressed in milliseconds. The larger the R-R intervals, the more finely our cardiac system can adapt to our needs. This cardiac responsiveness is the sign that we are in a state of homeostasis. The body is then self-regulating, with a perfect balance of the autonomic nervous system, notably between the sympathetic and parasympathetic systems. The sympathetic nervous system's function is to regulate our body's fast automatic responses. It controls breathing and heartbeats in particular. It is best known for preparing the body to “fight or flee”, via an increase in stress and an overactivity of the organs. When training — that is, the stress imposed on the body — is too great, the autonomic nervous system is dominated by its sympathetic branch. This is due to the body's need to prepare for the next hard blow you are going to inflict on it. The parasympathetic nervous system, on the other hand, takes care of the slow automatic functions, such as digestion and sexual needs. It is this system that enables the repair of muscle fibres and lets the brain rest. When it becomes too dominant, we feel urges to vomit, to cry or to release the sphincters. Training means playing between the different nervous systems. Tracking your heart rate variability is thus an excellent tool for determining whether your body is in balance or whether it needs rest time to return to homeostasis.

Measuring your heart rate variability

Measuring your heart rate variability means measuring the R-R intervals. On the order of a millisecond, the HRV measurement is very sensitive to measurement error, especially with the equipment at our disposal. Several tools allow this measurement, but the most reliable and accessible is one of the heart rate straps from Finland's POLAR, namely the H10. Paired with the HRV4Training app, the R-R measurement error has been estimated at less than 5% (HRV4TR/ECG in the image below).

Illustration (illustration being migrated)

A quick note: FSTBT is the strap from Finland's FirstBeat, recently bought out by Garmin in order to be able to use their algorithms built around recovery questions. Once you have a measuring device, you will need to choose the right moment to measure your heart rate variability. Two solutions are generally used. The first consists of wearing the device at night and taking several measurements automatically. This method is however disturbed by the different sleep cycles. The second solution, and the easiest to implement, is to take a measurement upon waking. This requires a little organization, but waking is the ideal moment, because we are not (yet) affected by the stress of daily life. The latest research indicates that a measurement taken lying down over a duration of 1 to 5 minutes is enough to get a reliable result. Now, one measurement point is not enough. To be able to use heart rate variability, you will have to estimate a trend and measure HRV every day. The reason is that each person is unique, and genetics plays a substantial part in the R-R value. You therefore need to know your body before being able to say what is normal or not about your heart rate variability.

Short- and medium-term variations in your heart rate variability

From the value of the R-R intervals, most algorithms calculate a quadratic mean, rMSSD. Let us simply remember that the higher the rMSSD, the more the parasympathetic system takes over. HRV (or rMSSD) is affected by the accumulation of the stresses we undergo in our lives. The exhaustive list of these stimuli is near infinite. We can nevertheless split the stimuli into two types:

Stimuli of the first type are those that will affect our body in the immediate future. Among them are intense training sessions, sleepless nights, alcohol excesses, big trips, etc. Anything that will impact our state of freshness within 24 to 48 hours. These stimuli will cause the rMSSD value to plunge sharply, meaning that our body needs rest time to return to its normal state. Time makes it possible to determine the normal rMSSD reductions caused by an intensive training block. Once that is acquired, we can then determine whether the HRV's behaviour is the expected one or whether we are too stressed. Stimuli of the second type will affect HRV over a longer term. If training is well suited, then HRV will tend to remain stable or improve. Conversely, an HRV that keeps dropping slowly but surely indicates that something is wrong. Perhaps everyday stress is too high to follow such intensive training. Perhaps we are not sleeping enough or not eating properly enough. In any case, a constant drop in HRV calls for investigation.

Tracking HRV

Now, if you wish to track your heart rate variability to steer your training, you will need to be patient at the start. Indeed, as written above, HRV is affected by everyday stress. Yet, during the first measurements, we do not know whether they are taken in a state of balance or imbalance of the nervous system. You will have to accumulate measurement points to get an idea of your nominal state. How many? The HRV4Training app recommends 60 days. Once you have your personal HRV trend, you can then sort out the fluctuations due to daily life from the fluctuations due to stimuli of the first and second type. Concretely, on our side, we take the measurement via the HRV4Training app and a Polar H10. Once the measurement is done, the app sends the heart rate and HRV measurements to TrainingPeaks, which lets us see the trends. These trends can also be viewed directly from the app. Incidentally, HRV4Training offers a traffic-light-style indicator: red = problem, orange = caution and green = normal. What we are looking for in the trends is to analyse whether the HRV reductions are consistent with training, and whether HRV returns to a normal point during rest phases. Over the long term, we also monitor that HRV remains stable or improves very slightly. The whole set of measurements must also be contained within a confidence fluctuation interval, a picture of how our body functions. That is why comparing your HRV values with others' makes no sense. The fluctuation interval and the HRV average are specific to each and every one of us.

Second safeguard: rate the quality of your sessions

Less objective than the heart rate measurement, rating your sessions once completed lets you read weak signals of overload. We can choose our own rating system, from 1 to 5 or from A to F. The important thing is to have a system for encoding the sensations of the session. For example:

By following the evolution of the ratings over several days, it is possible to detect recurring problems. If the number of sessions rated 2 is high, for example, with a 1 from time to time, it means we are doing too much. If the number of 5s is high, it would be worth loading the training a little more. Incidentally, it is very interesting to attach to this rating the aches or minor issues that appeared during the session. If the pain, even benign, persists, it will then be time to be proactive about resolving it.

Third safeguard: measure your weight

A well-designed training programme pushes the body close to its limits. Eating well and hydrating well are essential to give the body a chance to adapt. Measuring your weight every day (under the same conditions, for example getting out of bed each morning) and following the evolution are revealing of your state of fitness. If weight loss is too great, we need to review the hydration, nutrition and training load trio. If weight gain is too great, we are either building too much muscle mass or eating too much. Careful though: there is no question here of going on a diet — weight loss must not be brutal, at the risk of depleting the body of essential nutrients. Nor is there any question of developing an obsession around your weight: it is only one reading among others. Other, more reliable means exist to follow your progress and raise your fitness level.

Fourth safeguard: take a weekly rest day

Although training should be constant and rest phases minimized, taking a weekly rest day is a very good tool to let the body recover (along with modulating the load in cycles). During this rest day, it is advisable not to do any activity outside Z0. This day can be an opportunity to take the time to eat, get a massage, do some stretching or yoga. We can also put it to good use to take care of gear and prepare the coming week's outings. It is also a good opportunity to look at all the recorded data and try to perceive trends in your training.

Fifth safeguard: rate the quality of your nights

Fifth and last safeguard: rating the quality of your nights and naps is an interesting tool for estimating your level of recovery. We recover while sleeping, particularly during the REM sleep phases. Hence the importance of putting yourself in good conditions to optimize your nights: good (and clean) bedding, a dark and silent room, without forgetting to plan sleep time slots. We can, for example, plan to go to bed every day around 9 pm and not get up before 7 am, giving a sleep potential of 10 hours. That way we will indeed manage to draw 8 hours of sleep from those 10 hours.

high-stress moments of life. We’re talking work deadlines, renovating your house or the build-up to Christmas.

The Rusko Orthostatic Test

The simple but time-consuming Rusko orthostatic test was developed by the famed Finnish exercise scientist Heikki Rusko
as a way to monitor for overtraining among high-level cross-country
skiers at training camps. It requires only a basic heart rate monitor
with real-time display. Here is how it works:

A well-rested, fit athlete will display a low resting heart rate, a
rapid heart rate response in the first 15 seconds of standing, and a
rapid fall in heart rate during the next minute. Whether the heart rate
rises or drops during the final 30 seconds is also a good indicator that
there has been a positive training adaptation. Dropping indicates a
higher fitness and/or recovered state. This test works because your
heart rate is controlled by your nervous system, which is one of the
first responders to stress. The science behind this test is detailed in
many places so we are only going to address the use of the test. The test is relative only to the individual, and no comparisons can
or should be made to others. You should establish a baseline of testing
during a period of low training stress to see what your “rested state”
heart rate response is like. After a few months of routine data
collection, you will see trends and be able to relate the test to your
perceptions. This test has proven fairly reliable in our experience. It
can help guide your training by eliminating self-doubts on those days
when you are just not sure if you should be resting or training. It can
be particularly helpful in avoiding a downward spiral into overtraining. The Rusko orthostatic test is not perfect, however. The nervous
system is sensitive and complex and responds to other inputs than just
your training. Had a bad dream? Had a fight with a friend? Dreading a
test at school? Don’t bother with this test then. It allows you another
means of dispassionately assessing your preparedness for training. Its
real drawback is that it requires a relaxed several minutes to perform.
You can’t be late for work and get any meaningful info from this test.
It is highly subject to your emotional state of arousal. If you are
nervous about the test coming back negative, it almost surely will.