Sunday, October 6, 2019

"Overtraining" in the News

An NPR article caught my attention last week. John Hamilton's article, "Too Much Training Can Tax Athletes' Brains" was effectively instant click-bait to me. And it has provided much food for thought over the last few days.

Hamilton interviewed the authors of a new study exploring the effects of training induced fatigue on exercise performance, cognitive fatigue, decision making, prefrontal cortex activity, etc... You can read the full text of the cited article in Current Biology here.


What's it all about?


The study divided 37 "competitive" triathletes into 2 groups - a control group maintained its normal training volume and an overreaching group (OR) that increased its training volume by an average of 40% for a 3 week overload period. Both groups were given a psychometric questionnaire every 2 days to assess subjective fatigue/mood. Brain activity was assessed via MRI pre- and post-training period. Subjects were also asked questions to assess decision making abilities. The questions were designed to assess whether athletes were more likely to seek immediate gratification or long-term reward. Questions like, "would you like $10 now, or $50 at a later date?" Essentially, what's the athlete's discount rate?


They found the OR group was more inclined to choose immediate gratification rather than seek the long term reward - in other words, they became more impulsive and chose the "easy-out." The MRI results showed that the OR athletes exhibited less activity in a prefrontal cortex area that's thought to be involved in complex decision making.


So What?


One issue I have with the article is the bias to recognize overtraining syndrome as a syndrome. Instead of calling it "overtraining" can't we just call it fatigue? In fact, most sports scientists are starting to use the term "overreaching;" overreaching can be further divided into functional and non-functional. Obviously, there are ethical and health constraints that prevent scientists from trying to truly overtrain athletes in the lab, but if your study is supposed to address overtraining, can you do that if you don't have overtrained subjects? Is it fair to assume that overtraining, or non-functional overreaching, is just a more extreme version of fatigue?


If you'd like to read the European College of Sports Medicine and American College of Sports Medicine's joint consensus statement on overtraining, you can see the full text here.


Overtraining, fatigue, a shift in priorities?


The abstract of the latest article starts with, "Overtraining syndrome is a form of burnout, defined in endurance athletes by unexplained performance drop associated with intense fatigue sensation." Well, if you've ever been several weeks into a block of hard endurance training, you know you're tired - you may experience "intense fatigue." But does that mean you're overtrained? I'm not sure it's that easy to define. If you believe you're doing good work and the work will pay off in the form of a strong race performance, you might be able to justify the pain and suffering of training and continue on. But if you start to believe the work is not worth the reward anymore, and you give yourself the excuse of being "overtrained," does that mean you are? Does it become a self-fulfilling prophecy, leading you down a road to sub-par performances because you think something is wrong with you?

I take issue with a few points from the NPR article and the study. But I recognize I am biased - I don't like to acknowledge "overtraining syndrome" as an actual syndrome. Primarily because I do not think that there are any physiological parameters that can indicate someone has overtrained. One cannot simply take a blood test or strap on a heart rate monitor and determine whether he/she is overtrained. We can test for and athletes can feel fatigue, but fatigue is reversible given adequate rest. Rather, I think that "overtraining" or "burnout" is often a state of mind - it's a loss of interest and a lack of motivation. It's the point where the athlete believes the reward for suffering through hard work and training is no longer worth the sacrifice. But what I find interesting about this study is that it links physical and mental fatigue. It appears that when you're physically exhausted, your brain may not work in the same way.

I used to love listening to Mike Creed's "Open Mic" podcast - and one of my favorite episodes was an interview with coach Dean Golich. Golich has coached multiple Olympic and World Championship athletes. My favorite quote from the podcast is Golich's take on overtraining. He states,

"When people say that someone 'over-trained' or got 'burnt-out'... I don't know if that's the case. It's that you come to the realization of what it takes to succeed and you're just not willing to do it anymore."

And I think this sums up some of the findings from the article - at some point, athletes can no longer justify the work, the suffering, and sacrifice. And when they're tired, it's that much easier to justify stopping.

This is not to say that athletes cannot do too much. They certainly can and do. Fatigue is real and overuse injuries happen. But this has become my view of overtraining - it's not so much a physical ailment as it is a lack of motivation and will to continue fighting; to continue suffering and sacrificing to be the best athlete you can be.

But continuing the fight requires a lot of discipline and mental energy - and perhaps this latest study sheds some light onto why people stop. Physical exhaustion is also mentally taxing - and when you're exhausted it's a lot easier to say "enough."


Improved performance through overtraining?


Another issue I have with the NPR article is that it incorrectly uses the term "overtraining." In the overreaching group (OR), the athletes increased their training volume by an average of 40% for a 3 week "training overload" period. We can only say they acutely increased their training loads. This training overload resulted in fatigue - but fatigue often is necessary to provoke a desired training response. In fact, after a two week taper the OR group's performance improved from baseline. This follows the traditional model of supercompensation in biological systems - stress may weaken a system initially, but the stimulus usually provokes a response for the system to adapt. You could say, the 40% increase in training volume was an effective training intervention - not overtraining. If a group of athletes was truly "overtraining," by definition - you would not expect to see their performances improve.


Other implications of fatigue


The authors of the study also propose extreme fatigue could leave athletes susceptible to doping. And I can believe it - I've read this excuse a few times. Some athletes are just looking for something to make training and racing more bearable. Regardless, no matter how tired you are, I don't think there can be any justification for cheating. It's worth noting the study was funded by the French anti-doping agency. 

What I took away from the article - "Overtraining" is largely a mental game and your decision making and reasoning abilities may be impaired when you are physically and/or mentally fatigued. This could highlight the importance of scheduling mandatory rest periods during the year to stay fresh and setting multiple short term goals. Short term goals could provide opportunities to get "immediate gratification" every now and then. These goals could make it easier to stay focused and motivated a few days or weeks at a time and serve as stepping stones towards a bigger goal. If you've got a benchmark training session or race every few weeks, you'll be motivated to do your best to be ready for that test. But if you don't have anything on the schedule until 6 months at a time, how are you going to keep yourself accountable? Are you going to be able to justify suffering and sacrificing for the next 6 months? Will you when you're really tired?

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