Column 26, March, 2010

Recognizing overtraining and fatigue in running

To perform at our optimum we need to be able to determine the level of physical and mental stress our bodies can adapt to and improve under. Pushing our bodies beyond its ability to recover (over-training) will conversely cause a backward slide in performance, fatigue, and a higher incidence of injuries.

Derek M Hansen of Running Mechanics tries to prevent over-training in his athletes by looking at training in another way -What is the minimum amount of work I need to create improvement?

Coach Benji Durden believes in a similar approach when he says “Ultimately, the best runners are the ones who are willing to work very hard but who have a little bit of a lazy streak in them”.

Over-training isn’t just a plague for elite runners or those clocking big km’s, it can be a problem of too little recovery as much as it can be from too much training, so all runners are vulnerable. Scientists have identified more than 130 signs of over-training, including;

Elevated heart rate
Decreased appetite
Increased recovery times after exercise
Disturbed sleep/need for more quality sleep
Low blood pressure (or high resting BP in the case of sprinters)
Increased incidence of infections and colds which often linger
Decreased performance
Weight Loss
Increased irritability/mood state disturbance/depression
Decreased libido
Increased emotional stability
Loss of desire to train/compete
Postural hypotension (causing dizziness on standing)
Increased incidence of injury
Reduced plasma lactate levels during exercise (sprinters)
Decreased free testosterone levels
Increased cortisol
Progressive anaemia
Decreased haemoglobin
Decreased hematocrit

Many of these indicators can be tested in the lab. While this is useful in ruling out unresolved infections, Epstein-barr virus (glandular fever), anaemias and immune deficiency, it is generally not practical or affordable to carry out on a regular basis.

Often runners may not even recognize they have over-stepped their limits until a muscle tear or stress-fracture presents. So how can we more easily identify fatigue?

Simple quantifiable performance measures

If an athlete is training diligently and performances have hit a long plateau or are lacking, prescribing more rest may be the answer. Running performance is easily measured by the clock, provided we are comparing similar terrain and conditions.

Runners who cross train with weights can use this form of training to provide objective performance indicators. Have you had to reduce load or fatigue earlier than usual?

Some coaches periodically use the vertical jump test to give on-going information on the athletes’fatigue status.

Deterioration in biomechanics and running form:

A gradual reduction in running technique, especially towards the end of a session is a clear sign of fatigue. Be aware of;

Postural changes – the hips become closer to the ground, knee flexion increases and the foot stays in contact with the ground longer with each stride.
Improper foot-strike can be heard with heavy foot-falls.

Video analysis can be useful, comparing against a baseline video when the athlete was fresh.

Muscle tone analysis

A trained massage therapist is extremely useful here. In some athletes, excessively high muscle tone is a sign of high workloads and inability to recover appropriately.

In other athletes, very low muscle tone can be an indicator of excessive fatigue and lack of preparedness. Often athletes aren’t aware of how stiff and sore they are until they jump on the massage table!

Hi-tech heart rate monitors

The latest heart rate monitors, eg Polars’ RS800CX, can measure Heart Rate Variability (HRV) to give a non-invasive indicator of recovery status. HRV indicates the fluctuations of heart rate around an average heart rate (HR). A HR of 60 beats per minute does not mean the interval between heartbeats is exactly 1.0 sec, instead they may vary from 0.5 – 2.0 secs.

Healthy individuals exhibit greater variability between heartbeats than those who are stressed mentally and physically. During exercise HRV decreases as heart rate and exercise intensity increase. Comparing our HRV at a given running pace and heart rate can give us information about training load and stress, however they do not come cheap, at around $900NZ.

Life analysis

While many indicators for over-training are objective, we need to also take a ‘Big Picture’ look at other life indicators of fatigue, including sleep disturbance, reductions in academic performance, relationship problems, irritability, appetite and menstrual changes.

Jack Raglin, PhD, researcher on sports psychology at Indiana University, suggests that runners play close attention to their moods. He believes psychological state is a better diagnostic tool than physical factors when determining over-training. “Changes in demeanor are an early sign of over-training, so if a runner recognizes this symptom, he can adjust his training to prevent physical damage,” he says. While some irritability after a period of hard training is normal, a change in disposition shouldn’t last more than a day or two.

Catching over-training early means it may be remedied by taking the day off or postponing tough tempo sessions. Waiting until the syndrome becomes more advanced will mean greater downtime is needed to recuperate.

Next month I’ll take a closer look at how to hasten recovery once over-fatigue has been identified.

Marnie Oberer