Overtraining: what it is and how to prevent it

Train smart and you'll hit PBs, says Dr Catherine Spencer-Smith. Overtrain and your season will scream to a halt. Here she discusses why overtraining is harmful and how to prevent it


There’s a phrase that fills the air of coaching symposiums all around the world: train smart. In short, as well as exerting your body, it means using your head. Apply the same energy to your recovery, diet and intensity and you’ll improve.


Don’t and not only will you increase your chances of injury, you’ll be a prime candidate for the athlete’s worst nightmare – overtraining.

In this article, you’ll discover its symptoms, why you get it, who’s most susceptible, how to remedy it and how to avoid it in the first place. Note to the hardcore rest-is-for-wimps fraternity: we implore you to read on – it will improve your results.

What are the symptoms of overtraining? 

Overtraining is the process of excessive training caused by inadequate recovery, which leads to symptoms such as fatigue and poor performance. This is different to the day-to-day fluctuating feelings of tiredness after exercise, and it’s sometimes referred to as ‘burn out’ or ‘staleness’.

When you train hard – flexing your quads up a 1 in 8, using paddles in a sprint swim session… – you stress your anatomy and physiology. During rest periods your body repairs and becomes fitter – a process known as ‘super-compensation’.

If you don’t allow sufficient rest or easier training within your schedule, your body can’t regenerate, meaning you’re already at a low ebb when starting your next training session. Continue down this debilitating road and you’ll arrive at ‘Destination Overtraining’.

Initially this might be a feeling of excessive fatigue and poor performance, but you may ‘progress’ to experience a sensation of ‘everything seems a huge effort’.

To further deepen the gloom, coughs and colds might become the norm, alongside sore muscles, irritable mood, difficulty sleeping, reduced appetite and even weight loss.

Sadly, being goal-orientated devils, some triathletes spot that their performance is tailing off and react by thinking, ‘This isn’t good – I need to train harder.’

They up the intensity of their schedule, but this stresses their bodies even harder, and then a viscous cycle develops and leads to full-blown symptoms of overtraining.

How to avoid fatigue

Overtraining is potentially a problem for all athletes, but is more common in triathlon, when the temptation to train as hard as possible in all three disciplines is high.

Long hours of lonely bike rides, combined with a full-time job and the trials of raising a family, can lead to cutting corners in terms of rest and sleep, ensuring that the body is always playing catch-up.

It’s a serious problem with up to 65% of all elite athletes experiencing it at some time in their career, and it’s considered to be the main cause of injury in elite Ironman athletes.

Elite athletes are at a greater risk than us age-groupers because, although in beginners small amounts of training produce large performance benefits, in elite athletes a great deal of work has to be consumed to achieve just a small increase in performance.

While athletes throughout time would have no doubt suffered from the symptoms of overtraining, it’s only been widely recognised by doctors and coaches alike in the past 20 to 30 years thanks to the advent of sports science and physiological testing.

Many well-known athletes have succumbed to a spell on the sidelines. Back in the early 80s, Alberto Salazar (World Champion and Olympic marathon runner) famously spent years battling with it.

His former coach, Bill Dellinger, realised that he was slowing down despite training harder, and recommended that Alberto should cut back on his training and rest a while. This went unheeded, and Alberto ran himself into the ground during training and racing.

His blinkered approach meant that he almost lost the ’82 Boston Marathon to his fierce rival, Dick Beardsley, in a riveting sprint to the line.

How to measure your training state

So how do we know we’re becoming overtrained? Apart from the typical symptoms of fatigue and irritability, you’ll under-perform. This will show itself in your swim, bike and run pace.

If you were to undergo an OBLA (Onset of Blood Lactate Accumulation) test – where you undertake a graded test (increasing speed each time) on a treadmill, taking a blood sample at different increments, which is then tested to measure the point at which lactic acid starts to accumulate (the point at which the levels rise above 4mmol/l is said to be the OBLA) – you’d find that the switch from working aerobically to anaerobically would occur at a decreased work rate.

In other words, your body would appear to find the work even more taxing than usual.

For years, coaches and athletes have measured their early morning heart rate (HR) as a guide for problems such as overtraining, the idea being that overtraining might produce an elevation in this heart rate.

Science hasn’t really shown this to be the case, though, because many factors can alter early morning heart rate, including a mild illness, medication and so on.

A clearer scientific measure for aiding the diagnosis of overtraining is the maximal heart rate of an athlete. This could be quantified during a progressive exercise test.

For example, on a treadmill where you progressively speed up at set intervals until you can’t keep up with the current pace. An overtrained athlete will exhibit a maximal heart rate that’s 5-10 beats per minute (bpm) lower than their norm.

However, not all of you will have access to specific testing facilities, so you must be vigilant for the feelings of excessive fatigue and a drop in performance – and mood.

Keeping a logbook will give you the greatest chance of spotting the early signs of overtraining.

Your logbook should contain a detailed diary of your training schedule: details of warm-up and pace; your perception of the amount of effort it took during that session; your heart rate and recovery rate during the session; your general feelings of well being.

Give yourself a score out of 10 for how stressed/fatigued/irritable you are.

How sore do your muscles feel? Make a note of how much sleep you’ve had. Record symptoms such as sore throats and colds. Women should note where they are in their menstrual cycles.

Be fastidious in writing down exactly what you’ve eaten and drunk all day, and any medications you may be taking.

Although no single parameter is going to make a diagnosis of overtraining in its own right, a look back through your diary will make you (and your coach) aware something is beginning to slip, and how this might relate to your training regime.

How to avoid overtraining

The critical concept to get your head around is that there has to be a balance between training and recovery. There should be gradual increases in the volume and intensity, and the schedule should be periodised, consisting of several cycles of effort.

There should be times in all schedules of enforced rest, and cycles of high-intensity training should be followed by cycles of low-intensity work. There should even be times in the annual calendar when there is a total ‘down-tools’ time – even Paula Radcliffe used to take a month off each year.

Don’t try to cram too much into one week, and never ‘enjoy’ more than two or three high-intensity workouts per week. If you’re training for a long-distance event, don’t get caught in the trap of doing most of your training at weekends.

Put your long run midweek and the long ride on a Saturday or Sunday. It’s natural to feel a bit tired after a workout, but it should only last up to 24hrs.

If it’s lasting longer than that, you need to back off. Think hard about what you want to achieve in terms of competing for that year and avoid multiple competitions that don’t allow you to recover in between.

If you don’t have a coach, we’d thoroughly recommend getting one, or at least joining a club so that you can find yourself a mentor.

Training plans must be tailored to the individual requirements of the athlete, with room for adaptation according to feedback. A wise, supportive coach should reign in an overzealous athlete and encourage smarter training, with plenty of rest, restorative treatments and an excellent diet.

How to act on the signals of overtraining 

If you do suspect you may be overtrained, act immediately. Firstly, get yourself a proper diagnosis from a doctor. The treatment for overtraining is rest, and the longer the symptoms have occurred, the more rest that’s required to bring about a full recovery.

Although many triathletes understand this, they attempt to ‘rest’ from training in the discipline that’s taken a nosedive, and try to compensate by overly cross-training in the other two disciplines. This doesn’t work. They need to rest from the swim and the bike and the run.

But how long is enough rest? Well, it’s variable, but if an athlete has shown signs of overtraining for, say, four weeks, then stopping exercise for a week may be enough time off. After that, the athlete would should resume training on alternate days, ensuring the situation was carefully monitored.

Triathletes with more chronic symptoms may have to rest for months to achieve a full recovery. Obviously a common fear is that if you rest you’ll lose any remaining fitness.

Thankfully, recent studies have shown that reducing your training for three weeks will not overly decrease performance, and it’s certainly better to be undertrained than overtrained for a competition.

Top tips for age-groupers to avoid overtraining

Most of us aren’t privileged, or talented, enough to be sponsored to pursue our sport, which means working for a living – and, importantly, taking your daily life into account when planning your training schedule.

Ideally, avoid intensive periods of training around major life stresses. For example, moving house, changing jobs or even getting married.

Beware of training if you feel in anyway unwell. Exercising with a temperature, chest infection or viral illness won’t be productive, and you may risk prolonging the length of time that you’re unwell, or even push yourself into a position of chronic fatigue.

Diet also plays a key role. Many triathletes become glycogen depleted when they train hard, resulting in loss of power and endurance and a feeling of wading through treacle.

Keep a constant source of carbohydrate to hand when training – energy bars, gels or a light carbohydrate drink – and prepare your meals to be ready in advance of heading out on the bike or for a run.

That way, when you return, you can refuel as quickly as possible (ideally within an hour of finishing) and you’ll not flop into bed too tired to cook.

You should also bear in mind the nutrition content of your meal. Some athletes become carb-obsessed and fail to eat enough protein – a particularly common trait in vegetarians.

So all of you must include a protein-containing food at every meal time. For example, fish, lean meat such as chicken, beef or pork, eggs, nuts and legumes.

Many vegetarians/vegans also fall way short of enough vitamin B12 in their diets. Vitamin B12 is needed to make red blood cells – if deficient, you could become anaemic – and it’s also important for the healthy functioning of nerves. Using a supplement is an option because the richest source of B12 is in meat and fish.

Women tend to be on a knife-edge in terms of iron because of blood loss during menstruation, so they should eat iron-rich foods (for example, red meat) and improve the uptake of iron into the body by taking on vitamin C at the same time (for example, a glass or fresh orange juice).

All of you must make sure that you’re drinking enough. An isotonic sports drinks, for example, sipped throughout the day should ensure that when passing water, the stream is almost clear/colourless urine.

Finally, when you’re in competition time, make extra allowances for the fatigue of travelling. And if returning from abroad give yourselves a few days of gentler training to allow yourself to recover from the effects of jet lag – ideally one day per hour away from GMT.

Is overtraining preventable?

Everyone has experienced a modicum of muscle soreness after a particularly debilitating workout, but there comes a time when less really does equal more. Without rest and recovery, your regime can backfire and actually decrease your triathlon performance.

Overtraining is preventable, but unfortunately many people wait too long before realising it’s time to do something. It’s important to follow a structured programme, with rest and recovery given as much emphasis as the bikes and runs.


Above all, when you turn up for a competition, turn up having trained smart and trained safely.

To read more on overtraining, including testimonials from elite triathletes, check out How to Train Smart

And for more expert training advice, check out our vast library of content in our Training section