Thursday, November 21, 2013

3 Simple tests that can help you avoid Overtraining

Alan Couzens, MS (Sports Science)

"Enter, stranger, but take heed
Of what awaits the sin of greed,
For those who take, but do not earn,
Must pay most dearly in their turn.
So if you seek beneath our floors
A treasure that was never yours,
Thief, you have been warned, beware
Of finding more than treasure there.”

―     J.K Rowling, "Harry Potter & The Sorcerer's Stone"

In my last article, I discussed the difference between ‘failing adaptation’ and ‘compromised adaptation’ & suggested that, as coaches, we are far more likely to come across the second scenario, where an athlete is not clinically overtrained to the point that he can no longer adapt to training but rather just tired enough that he/she is not getting “all that they deserve” out of the work that they’re putting in.
Because this situation is more subtle than full blown over-training, the signs are also more subtle. The ability of a coach or athlete to pay attention to and heed these signs is one factor that separates a decent coach from a ‘master coach’. A decent coach will incorporate sufficient recovery to ensure than an athlete keeps progressing safely over a long period of time. A master coach will respond daily to the signs of the athlete so that improvement is not only consistent but the rate of improvement is maximized.

So how do we go about keeping our training response moving forward at the fastest possible rate? What are some signs that we can use to help to tell us to ‘back off’?

3. simple measures have been consistently linked with both the (‘red light’) overtraining syndrome and the (‘yellow light’) blunted training response…

- Resting Heart Rate Variability
- Submaximal Exercise HR
- Neuromuscular Efficiency

1.       Morning Heart Rate Variability/Resting-Standing Delta

As noted in the previous study by Hautala et al.(2003), lower levels of heart rate variability are a sign of autonomic fatigue and a good predictor of a blunted training response. Considering a difference of ~20ms can amount to a difference of 12% improvement in VO2max off the same training load, this is a number worth paying attention to!
Several systems are now available to monitor and record HRV patterns to signal over-training and identify optimal days for loading. Most of these companies tend to keep their algorithms proprietary and I have trust issues so I’m not going to implicitly validate any of these systems J

However, a ‘low tech’ alternative that I’ve found useful (that I stole from Eastern Bloc coaches) is to measure lying and standing heart rate each morning. The delta between these 2 measures, when recorded over a long period of time, is also a very good indicator of autonomic fatigue. For example, in the study referenced above, the group with the highest HRV also had the greatest gap between lying (sleeping) and standing (waking) heart rates (24bpm). The group with the lowest HRV had a mean difference of only 17bpm.

Your numbers may be different to these. Things like aerobic fitness, size of the athlete, gender, etc. will all come into play. The important thing from a practical standpoint is how this morning’s numbers compare with your normal. A difference of 6-8bpm from your normal is worth paying attention to and is likely a sign that something is a little ‘off’ and your training response for that day may be compromised. Remember, this gap amounted to a 12% difference in training response in the study. May be a good day to go easy?

Differences of larger than 8bpm are typical of more serious situations like major physical or psychological stress – infection, very poor sleep etc. On these days, no training or VERY light training may be most appropriate.
I like to use morning heart rate as the first check in and first ‘line of defense’ for the super-committed athlete. It offers a good objective marker of where things might be headed. Rarely though, would I suggest that the athlete not move onto the second step in their ‘readiness to train’ assessment, i.e. some submaximal testing during the warm up of their first session of the day….

2.       Submaximal Exercise HR

An even better indicator of a blunted training response is exercise heart rate.
Studies have consistently shown that exercise heart rate is affected when an athlete is over-reached. In the case of sympathetic over-reaching, exercise HR is higher for a given workload. In the case of parasympathetic over-reaching, it is lower. For example, Hedelin et al. (2000) found a mean difference of 8bpm (~5%) at the same absolute workload when a given athlete was (parasympathetically) over-reached. This ‘inverted U’ relationship between training response & high/low HRs for a given power output is shown visually below.

This chart visually describes an important, if somewhat obvious, physiological effect. When the body is already dealing with or absorbing other stressors going into a workout (indicated by high or low HR) the training response that the athlete gets from that workout will be compromised.
Smart coaches have used this effect as a good indicator of when an athlete is ready for hard training. Swim coach, Bill Sweetenham, for instance, has used the “individual checking test” as a readiness marker prior to hard training sets. The test is simply a series of submaximal swims at a prescribed pace, with note taken of the swimmers heart rate and stroke counts and how they compared to “normal” for that swimmer. The triathlete who trains with pace and power can take a similar approach…

When power and heart rate zones are known for an athlete (for a given block of training) it is very easy to include a short set in the standard warm up at a prescribed submaximal pace or power and watch what heart rate that elicits. For instance, an athlete with an AeT (bottom zone 2) power of 200W could include a standard 15min segment at 200W in the warm up prior to a key set with average HR (and ideally cadence) recorded for the segment. Similar to the resting data, heart rates on ‘normal’ days will tend to fall within a pretty narrow range of +/-5% (as shown on the chart above). This brings us to what I like to call the ‘2 zone rule’ of overtraining.

In practice, this means that, for the bulk of sessions, both HR & Power should fall within a 2 zone band. Even accounting for appropriate decoupling, athletes should avoid situations in which they are putting out easy watts at greater than steady HR and vice versa.

If we apply this to the ‘warm up’ test; on any given day, this athlete with an AeT of 200W should observe a heart rate somewhere in their easy-steady (Zone 1-2) range from their AeT power effort. If the athlete fails to elevate their heart rate to at least their easy zone or if their HR is already exceeding their steady zone, something may be amiss or, in the terms of this article, the athlete may be running up on a ‘yellow light’ & may wish to schedule an easier day (as training response is likely compromised).

A worked example...
Our athlete's 'normal' AeT heart rate is 130bpm at an AeT power of 200W. However, on this day, he notices his heart rate is 140bpm (+8%), putting him into his 'yellow zone' and indicating his system may not be 'firing on all cylinders'.
You’ll note that Sweetenham recommends recording stroke rate/length data during this test as well. There is a good reason for this…..

3.       Neuromuscular efficiency

Fatigue of the neuro-endocrine system not only manifests on the endocrine side of things, as highlighted above, but also on the neural side of things. Therefore, things like co-ordination and rate of contraction are affected. Soviet coaches have long used different measures of this to assess over-training in their athletes. Things like hand dynamometers, vertical jump tests and even simple ‘tap tests’ where an athlete finger taps as many times as possible within a minute all help to discern the current state of an athlete’s neurological system. In the case of this test, the Soviet coaches found a significant difference between how many ‘taps’ the athlete could get done when they were ‘normal’ vs when they were ‘fatigued’ and different still to when they were ‘peaking’.
We’re already time crunched. Maybe we don’t have time to do a tap test every morning. But we all do have time for a tap test with our feet – on the ground – every time we go for a run J As Bill Sweetenham suggested, there is benefit to monitoring cadence during your warm up test, whether swim, bike or run. When athletes are tired, cadence/technique is affected. This has implications beyond simply indicating over-reaching. As athletes and coaches, we have to ask the question, do we want to be performing hard training under conditions of altered technique? Clearly, from an injury risk standpoint, the answer is no! Therefore, this is perhaps the strongest tip off to back off a little from any planned hard training on that day.

Similar to heart rate, ‘healthy’ cadence tends to operate within a range of ~+/-5%. A runner with a typical cadence of 87spm may see normal variation of ~4spm (83-91) but a difference of more than this might be a sign that the athlete is too tired to get a lot from their training that day. Similarly, in the pool, a swimmer who swims ‘steady’ at a normal rate of 45 spm may be considered significantly fatigued if it’s taking them 50spm to hold their normal warm up pace.

So what do you do when you run up on a yellow light?

I used the red light, yellow light metaphor intentionally to suggest that whether you stop at or roll through these yellow lights is a judgment call. Make no mistake, load is and always will be a central element to performance. An athlete doesn’t achieve their potential by being excessively cautious. However, on the flip side, an athlete doesn’t achieve their potential by being reckless either. The middle road will balance risk and reward on any given day. The purpose of becoming aware of the above signs is to put the coach and athlete in a better position to make intelligent judgment calls. Things you may consider when you come up on a yellow light…

·         Is there room within the week to bump this key session to a different day (when the athlete is likely to get more response from it?) & replace it with an easier session today?

·         Is this yellow light a one-off occurrence or am I pushing my luck (and headed for a red light?)

·         Are there proactive things that I can do to get back to ‘green light status’ as quickly as possible – catch up on sleep, get some good food in the system, get a massage etc.

By paying attention to your yellow lights, you can minimize the risk of unintended interruptions and keep yourself rolling smoothly towards your destination.
Train smart,



Michaela said...

I took a lot of additional reading to fully understand all of the jargon in this article, but it seems like it will be super helpful. Having suffered from and subsequently recovered from overtraining (it took more than a year), I'm pretty cautious at "yellow lights". I think sometimes, I may be too cautious and I've wanted something other than intuition to tell me when to go. (Clearly my intuition is not very good, since I've already overtrained once.)

Alan Couzens said...

Thanks Michaela!

Please let me know if there are any definitions or terms in the article that I could better define or add a link to. I sometimes do get a bit carried away with the jargon :-)

I think the level of caution that you should exercise when you come across a 'yellow light' is a function of how many of them you seem to be running across :-) If they start stacking up over the course of a week (3 or more) or training block, additional time off or a reduction in training load is probably warranted.

If it's more of a day here and there type of incidence, it might be more a case of bumping a key session to a different day to give your body a chance to bank a bit more energy and be in the best position to get the most from it.

Happy (& healthy) training!