Swimming, Overtraining, Recovery And Norepinephrine
To reach peak levels of performance, athletes need to find a way to blend hard training with exactly the right amounts of rest and recovery. Finding this optimal balance between work and recovery is a difficult challenge.
Unsure About Recovery Time
The main problem is not that athletes don't do enough work: indeed, they usually pile on too much work and fail to devote enough time to recovery. But the fact is that many athletes are unsure about how much recovery they need after each quality workout, and also about how much rest to build into each week, month and year of training.
This is unfortunate, because an athlete's pattern of recovery can make or break his/her entire training program.
Physiological Details Of Recovery
Recovery periods give the nervous, endocrine and musculoskeletal systems a break from the traumas of training and the opportunity to carry out some vital repair work.
The muscular system, for instance, often yearns for an opportunity to fix up cell membranes torn during strenuous effort; muscles also require the time and materials to fill energy depots and to synthesize new enzymes and energy-producing structures like mitochondria.
The spherical or elongated organelles in the cytoplasm of nearly all eukaryotic cells, containing genetic material and many enzymes important for cell metabolism, including those responsible for the conversion of food to usable energy. Also called chondriosome.
During recovery, the nervous system 're-wires' itself so that it can better control the specialized motor patterns used during training, while the endocrine system must return to equilibrium following the hormonal upsets induced by rugged exertion.
But most athletes don't care too much about the specific physiological details of recovery. Instead, they want answers to practical questions, such as:
- After a tough workout, how long does it really take to recover?
- How can I tell when I am really ready to perform another serious workout?
- When am I on the verge of overtraining and in need of a longer break than usual?
- Is there some way to monitor my recovery during specific portions of my training cycle to calculate whether it is going well?
Fortunately, there are relatively straightforward answers to these questions, and these are particularly important for athletes and coaches who believe that performance can be optimized by training at an extremely high level - close to the point of overtraining.
For such people, the closest approach to overtraining usually occurs just a few weeks before the most important competition of the year.
During the remaining weeks, training load is drastically reduced during a special recovery period known as a 'taper' to enable athletes to pull back from the precipice of overtraining and allow optimal muscular, neural, cardiac and endocrine adaptations to occur.
Such athletes need a monitoring system, which stops them toppling over the precipice, and indeed all athletes who hope to improve their performances can benefit from a monitoring plan, which provides information about the effectiveness of their recovery programs.
Good recovery monitoring systems keep athletes from doing too much or too little hard training.
In Search Of Reliable Indicators
Exercise physiologists have made a serious attempt to help athletes monitor their training and recovery and avoid the overtrained state. Physiologists who are interested in recovery have noted that athletes who perform well after tapering tend to show the following traits toward the ends of their recovery periods: improved muscular strength and power, fewer sleep disturbances, reduced stress and fatigue, lower rates of perceived exertion during exercise, lower heart beats during activity and brighter overall mood.
In light of these encouraging findings, scientists have gone on to explore whether these variables could be used as reliable indicators of effective recovery.
In one study, scientists monitored a group of swimmers over a 6-month season of training and competition, paying special attention to their ratings of well-being (eg fatigue, stress and muscle soreness) during a recovery (tapering) period.
They found that simple measures of well-being were reasonably good at predicting competitive performance improvement, accounting for 72% of the variation in improvement in race times compared with previous bests1.
Australian scientists recently attempted to broaden this research to include other variables besides overall well-being in a study of 10 elite swimmers (four male and six female) who were training and tapering for national championships. Five of these individuals were ranked in the fastest 20 times in the world and all were specialists at 100 or 200-meter swims, using a various stroke styles2.
Before & During Tapering
Before tapering commenced, the swimmers trained for a minimum of 18 weeks, with both the training and tapering plans designed by their individual coaches. For the week before and during the overall tapering period, all 10 swimmers kept a daily log of training details, which included swimming distance, time in the gym and training intensity, evaluated on a scale from 1 (very, very easy) to 7 (very, very hard).
Before getting up in the morning, the swimmers checked their early morning heart rates manually (by feeling their carotid arteries).
Body mass was measured daily, and menstruation status, illness and injury were also recorded. Ratings of well-being for fatigue, quality of sleep, stress and muscle soreness were recorded daily, again on a scale from 1 (very, very good) to 7 (very, very bad).
Before tapering, the swimmers averaged 47k of swimming per week at an average intensity of 5.3 (between 'hard' and 'very hard'). They also included 5.3 hours of gym (strengthening) work in an average week.
By the second week of the taper, they were down to 30.5k of weekly swimming at an average intensity of 4.2, and just 0.4 hours of strengthening work in the gym. At the end of the taper (which lasted for 17 days), the swimmers took part in the national championships.
The athletes were tested just before the start of the tapering period and again after two weeks of tapering (three days before competition). The tests included resting heart rate, blood pressure and blood lactate measurements, together with a Profile of Mood States (POMS) questionnaire.
The athletes were also checked during exercise: after a standard warm-up, peak force during tethered swimming was measured for each athlete using a load cell, attached to the swimmer by nylon ropes anchored to a waist belt. After an active rest of 400 meters of easy swimming, each subject completed an even-paced 200-meter freestyle swim at 80% of his/her personal-best pace. Five seconds after this, heart rate was recorded.
After another 400 meters of easy swimming (10 minutes total time), each swimmer completed a single max effort over 100 meters, using his or her principal racing style, with heart rate again measured five seconds afterward and blood lactate assessed five minutes later. The time in this all-out 100-meter swim was used as the performance measure for assessing the benefits of tapering.
In the event, the change in performance associated with recovery was most effectively predicted by changes in plasma norepinephrine concentration, heart rate after the max 100-meter swim and the POMS (Profile of Mood States) measure of the psychological state of confusion.
Decreases in plasma norepinephrine and increases in max heart rate were associated with better performances, as were reduced levels of confusion. Plasma norepinephrine was the best single predictor of performance, with changes in concentrations of this hormone predicting 82% of the variation between pre- and post-tapering performances!
A Neat Adaptation By The Body To Too Much Training
What conclusions can we draw from this? Bear in mind that norepinephrine is primarily secreted by nerve cells in the sympathetic nervous system, with the effect of elevating heart rate and boosting the rate of breakdown of glycogen and fat for energy.
It also enhances cardiac contractility, allowing the heart to pump more blood per beat. Thus, it would be logical to assume that a rise in norepinephrine levels would be advantageous - a hoped-for outcome during recovery.
Norepinephrine, known as noradrenaline outside the USA, is one of the 'stress hormones' and affects parts of the human brain where attention and impulsivity are controlled.
Along with epinephrine this compound effects the fight-or-flight response, activating the sympathetic nervous system to directly increase heart rate, release energy from fat, and increase muscle readiness.
It is released from the adrenal glands as a hormone into the blood.
Quite The Opposite
Surprisingly, however, the reverse is true. Research has shown that increases in plasma norepinephrine levels are actually linked with staleness in athletes. For example, in a fascinating 6-month study carried out with 14 elite swimmers, researchers found that the three athletes who exhibited signs of overtraining (based on performance decrements and high, prolonged levels of fatigue) had significantly higher levels of norepinephrine from the mid-season onward(3).
While this seems like a paradox, remember that increases in norepinephrine could be viewed as a neat adaptation to too much training - the body's courageous attempt to cope with an excessive workload. With lots of norepinephrine circulating through the tissues, heart rate would rise and energy mobilization increase as part of a concerted effort to withstand the unusually demanding training schedule.
In this light, drop-offs in norepinephrine could be seen as a sign that the body was under less stress, that it had adapted to the preceding training and had less need to fling the neuroendocrine system into overdrive in order to cope with the workload.
And that was precisely the case in the current Australian study: athletes with the biggest drops in resting norepinephrine levels tended to show the best improvements in performance. At the ends of their recovery periods, they were simply in less stressed-out states. (And here it is worthwhile remembering that norepinephrine and its sister epinephrine are considered to be two of the body's principal 'stress' - or 'flight-or-fight' - hormones).
A Reliable Marker?
The Australian research is in line with other work in this area, and therefore it appears that norepinephrine could serve as a decent and reliable marker of training progress and work-recovery balance. If norepinephrine shot up, it could well be a time to enhance recovery and cut back on total training load; declines in norepinephrine, on the other hand, would be a sign that training was going swimmingly.
The trouble with this approach, however, is that few athletes have the medical and/or financial resources necessary to monitor plasma norepinephrine on a regular basis. That being the case, what other - more convenient - tools could be used to assess the adequacy of recovery?
Heart-rate monitoring comes to mind, but both exercising and resting heart rates tend to do a remarkably poor job of predicting performance and assessing recovery status. One problem is that heart rate depends on a wealth of different variables, including emotional state, diet, hydration status, temperature, humidity, sleep patterns, sympathetic and parasympathetic nervous system activity.
One or more of these variables could easily mask the drop in heart rate associated with optimal recovery - or might even disguise the ill effects of a totally inadequate recovery!
Wellbeing & Mood States
Bear in mind that measures of well-being have often done a tremendous job of predicting performance and assessing recovery adequacy. In one study, information from the Profile of Mood States questionnaire proved to be the best single marker of disturbed performance in highly trained distance runners4. In this investigation, there were no useful changes in resting heart rate or perceived exertion during sub maximal exercise.
In yet another piece of research, the POMS questionnaire was given to 17 members of a French football team over the course of a season. Positive overall psychological changes, as indicated by the questionnaire, were linked with improved team performances, while negative scores were associated with reduced performance5.
The Profile of Mood States
The Profile of Mood States was developed in 1971 for people undergoing counseling or psychotherapy, but it quickly gained popularity with sportsmen and women. In fact, since the Profile was introduced into the sports world in 1975, a total of 194 POMS articles dealing with 32 different sports have been published in peer-reviewed scientific journals, and many studies suggest that the POMS can be used successfully to assess performance status in athletes.
One problem, though, is that the full-fledged POMS has 65 different questions, perhaps a few too many for the busy athlete. There is an abbreviated version, but even this includes 30 questions. Athletes are more likely to use a less time-consuming well-being checklist - one that takes up just a minute or two each day.
There are many different ways to assess well-being, but I have found the following 'quiz' an extremely handy way to monitor training load and recovery in the athletes I coach. There are only six points, and the whole test takes less than one minute to complete. Simply rate each statement on a 1-5 scale as follows: 1 = Strongly Disagree; 2 = Disagree; 3 = Neutral; 4 = Agree; 5 = Strongly Agree.
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