by Martin J. Trout

How do you prepare before a race?

Maybe you are one of those athletes who get into a total funk the week before a race, think that you haven’t done nearly enough training and decide to run every day up to the race in an attempt to super boost your fitness levels. Or, maybe you think that a total week of rest will allow you to recuperate all of the accumulated tiredness from months of training.

Both of these methods are wrong and we shall attempt to explain why.

The methodology of pre-race preparation is known as Tapering, but is also referred to as a process of “Peaking” (being totally race ready).

When considering an optimum tapering plan we should take into consideration two seemingly contradictory factors.

It is absolutely necessary to reduce organic fatigue but at the same time it is important to maintain levels of fitness.

If we do a lot of running, as in the first example above, in an attempt to maintain or improve fitness, we will increase fatigue. On the other hand if we stop running and just rest so that fatigue is reduced, we will inevitably lose fitness.

That would seem to be a Catch 22 situation but let us look at this closer.

The function of training is to create fatigue (organic stress) which, followed by a period of rest, creates a greater fitness (muscular, cardiovascular, neurological and even psychological). Fitness accumulates over a prolonged period of time whereas fatigue can accumulate in a very short period of time.

For example if we perform three consecutive days of hard workouts we will produce a great amount of fatigue but only a small increase in fitness. This is a very important point to keep in mind.

A significant reduction in training load will also negatively affect the “fitness” that has been achieved up to that point
A significant reduction in training load will also negatively affect the “fitness” that has been achieved up to that point

Reducing Fatigue

By diminishing the volume and degree of training stress the organism is allowed to recover and fatigue will be decreased. This takes place through the following physiological systems.


During a properly conducted taper period, parameters such as haemoglobin (oxygen carrying capacity of blood) and haematocrit (the percentage of red blood cells) together with the volume of red blood cells all increase. This produces a significant increase in aerobic capacity, particularly important for endurance athletes.


A number of studies and in particular a study by Aldercreutz et al. (*1) have investigated the changes in anabolic hormones (hormones that help build and repair tissue) and catabolic hormones (stress hormones that cause damage to tissues) during training and taper. In particular they noted a significant correlation between the improvement in the ratio between testosterone (anabolic) and cortisol (catabolic) and improvement in performance during a four week taper.

Neuromuscular Adaptations

Tapering (resting) has positive effects on muscle contractile properties. The effects would appear to be greater in Type 2 (fast twitch) muscle fibre than in Type 1 (slow twitch) muscle fibre. This would, therefore, seem to be more applicable to power or rapid movement athletes, however it should not be forgotten that power is an important factor in climbing and descending.

Immune Response

A significant adaptation that has been shown to occur in response to a taper is the increase in the cell counts for white blood cells, specifically eosinophils (detoxifying agents) and lymphocytes (white blood cells that fight infection). This suggests that there is an improvement in the body’s capacity to resist illness during taper.

Psychological effects

A number of studies (*2 & 3) have shown that significant improvements can occur during tapering, including reduced tension, depression and anger along with lessened mood disturbance and fatigue.

The Intensity Effect

As shown above it is very clear that physical, and indeed psychological, improvements can accrue through reducing training load and reducing fatigue.

However a significant reduction in training load will also negatively affect the “fitness” that has been achieved up to that point, and in a greater degree proportionately to the length of the tapering period. The famous Catch 22 again! Fear not, science comes to our rescue.

In a study (*3) at McMaster University in Canada, researches compared 3 different tapering protocolsRest Only (ROT), Low Intensity Moderate Volume (LIT) and High Intensity Low Volume (HIT).

Remarkably the HIT group showed a 22% increase in endurance, the LIT group improved by 6% while the ROT group stayed exactly the same.

The better results achieved by the HIT group were due to four main factors – they had more glycogen in leg muscles, their density of red blood cells was higher, blood plasma was higher and muscular enzyme activity in leg muscles was greater.

What was their recommendation? “Training intensity should be maintained, or even slightly increased. Such intense training is probably necessary to preserve some of the training associated adaptations that may be lost with the marked reduction in training volume.”

Methodology for Reducing Volume

There are two possibilities for reducing volume. One is that of reducing the frequency of training, for example only 4 training sessions a week rather than 6. The other is that of reducing the time and distance of each individual training session.

Fitness accumulates over a prolonged period of time whereas fatigue can accumulate in a very short period of time.
Fitness accumulates over a prolonged period of time whereas fatigue can accumulate in a very short period of time.


Most studies agree that a reduction of between 20 – 50% in frequency of training sessions is the ideal. However this is largely dependent on the number of sessions being carried out normally. An athlete who normally carries out 6 sessions a week could quite easily reduce this to 4 or even just 3 sessions. An athlete whose norm is 3 sessions a week would probably only want to remove one of these sessions.

Time & Distance

Studies(*4 & 5)on reduction of time and distance in regards to volume have shown that reductions between 50 – 75% are beneficial with endurance runners benefitting most from the lower of these figures.

In both these cases it is important to note the difference between a one week taper and tapers which may last for two or even three weeks, as would be the case for Ultra endurance events such as UTMB or Western States.

In these cases the recommendation would be to effect a gradual reduction where for example the volume and frequency might be reduced by 30% in the first week and by a further 30% during the second week.

Duration of the Taper

The duration of the tapering period is heavily influenced by the type of sport and the length or duration of the event to be undertaken. Other considerations regard each individual athlete, including age, sex (males generally require longer tapering periods due to higher levels of muscle mass) and physiological response.

In a 2007 study (*6) Inigo Mujika suggested that optimal results could be achieved through “A 2 week taper during which training volume is exponentially reduced by 41–60%.”

However in other writings the same author has written, “Our studies indicate that an efficient taper may last between one and four weeks. The optimal duration does not depend on age, experience or event distance. It depends on each athlete’s adaptation and recovery profile. Some athletes recover faster than others; some have long-lasting training adaptations, whereas some others detrain quickly.” This does not mean that Mujika, who is commonly regarded as a global expert on matters of sports tapering, is confused or has changed his mind but quite simply that successful tapering is highly dependent on the individual as well as many other variables.


We can summarize by saying that optimal tapering results have been found to take place with a 20 to 50% reduction in frequency, between 50 to 75% reduction in volume and a duration of between one to four weeks, while the intensity of training should remain the same or even at a slightly higher level.

This is a huge variation and clearly shows that tapering is more of an art than a science.

It is up to each individual athlete, alone or in conjunction with a coach, to experiment and find the optimal combination for their characteristics and the particular event to be undertaken.

It is however extremely clear that a rested and appropriately tapered athlete will have a distinct advantage over his un-tapered and almost certainly stressed and tired rival.

(*1)“Effect of training on plasma anabolic and catabolic steroid hormones and their response during physical exercise”.Aldecreutz et al., 1986.

(*2)“Less Is More: The Physiological Basis for Tapering in Endurance, Strength, and Power Athletes”. Murach & Bagley, 2015.

(*3)“Physiological effects of tapering in highly trained athletes”. McMaster University, Ontario, Canada, 1992.

(*4)“The Effects of Interval Training and a taper on cycling performance”. David Martin et al., 1993

(*5)“Physiological Responses to a 6-Day Taper in Middle-Distance Runners: Influence of Training Intensity and Volume”. Mujika et al. 2002

(*6)“Effects of tapering on performance: a meta-analysis.” Mujika et al. 2007


Martin John Trout
Martin Trout is an all round Adventurer, an accomplished ultra runner, mountaineer, ski mountaineering instructor and trail running coach at Endurance Training in Progress. He’s been living in Italy since the 1990’s.