'ology and 'osophy of the Taper

“Sleep! I feel the need of it. Yet my axe is restless in my hand. Give me a row of orc-necks and room to swing and all weariness will fall from me!”
J.R.R. Tolkien

It seems to be that time of year when everything starts happening all at once and if you blink you might miss something. This is my excuse for my abandonment of this blog. But I figured it would be a good time to share some things I was working on last year when I was to busy to blog. Good luck to everyone in the midst of taper season. Enjoy the restlessness. Bottle it up and then let loose!

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Taper Protocols for Distance Runners

Laura Roach

10/17/10

Introduction
Timing is everything in competitive distance running in which goals are made for a single race or a few championship races. Many effective training strategies in distance runners are based on Hans Selye’s theory on stress adaption in which physiological changes occur as a result of acute stress and recovery. According to this theory, in order to perform optimally the runner must be fully recovered from a succession of training stresses. Many runners and coaches use reduced training, also known as tapering, to increase the probability that they will feel good and perform well on race day. The trick is to design the taper in such a way that you do not lose any fitness gains from training, but are also fully rested with “fresh legs.” Although a large majority of researchers, coaches, and runners hypothesize that decreased training, particularly in the form of reduced volume, improves performance, the popular opinion is not conclusive on the most advantageous strategy for a pre-competition taper. The following review summarizes current theory and empirical evidence on physiological changes due to a variety of taper strategies and applies them to what should be recommended to coaches and athletes in order to boost race performance.

 

Review of Literature

Types of Taper

The most common elements of a taper include changes in volume (total daily and weekly distance), intensity (percentage of VO_2max), duration (day or weeks), frequency (number of runs per week), and type of reduction (linear, exponential, or step). A meta-analysis on taper research in endurance sports showed the highest increase in performance for tapers that involved a progressive (either linear or exponential) 41-60% decrease in volume while maintaining training frequency and intensity (Bosquet, Montpetit, Arvisais & Mujika, 2007). The highest effect sizes occur for tapers 1-2 weeks in duration.  The mean improvement for all taper studies was 1.98% with one study averaging an 8.91% performance gain. At a high-level of competition even very small performance gains can convert to outcome differentiation in important races. For example, Payne, Mujika, and Reilly (2009), point out that the difference between 4^th place and a gold medal (1.6%), and between 8^th place and a bronze medal (2.0%) were both under the mean 2.2% improvement after tapering found in the Sydney Olympic swimmers.  

Additionally, reduced training should maintain sport specific intensity. While a 7-day high intensity run taper with a 85% systematic reduction in volume improved a 5-kilometer treadmill performance by 2.8± .4%, the same taper volume and intensity on an ergonomically bicycle had no effect on run performance (Haumard, Scott, Justice & Chenier, 1994).

Pre-Taper Training

An important part of an efficient taper is the training that precedes it. In a mathematical model of taper characteristics, an overload period consisting of 40% increase in training for 4 weeks before the beginning of a taper increases the benefits of a progressive and step deduction in training. The model predicted the best performance increase to be 4.2%± 2.3% occurring after a 31 day progressive 39% reduction in training. This model suggests that the more training stress prior to the taper the greater the reduction and duration of the taper for optimum performance (Thomas & Busso, 2004).  

Mechanism of Physiological Adaption to Decreased Volume Taper

VO₂ efficiency is highly predictive of distance running performance suggesting oxygen efficiency may be a potential mechanism in which reduced training may improve performance. A study consisting of 6 weeks of intensive training and a two-week taper in track and field athletes showed significant increases in hemoglobin, mean corpuscular volume, hematocrit, white blood cell count, and VO_2max (Ashtyani, Mohammadi, Rahimi & Saravani 2006). The greatest hematological and VO_2max improvements were seen in a taper involving a gradual reduction in training load compared to a step-wise reduction taper, a 50% step reduction taper, and a 100% reduction taper. Although performance measures were not considered, these results agree with previous studies that indicate performance benefits from progressively decreased training (Bosquet et al., 2007). Alternatively, a study on highly trained middle-distance runners by Shepley, MacDougall, Sutton, Tarnopolsky & Coates (1992) showed that the high-intensity low-volume taper which showed the greatest performance gains had no significant effect on maximal O₂ consumption.  Still, significant increases were found in blood volume, muscle glycogen concentration, and strength in this study.

Another physiological mechanism for increased performance could involve recovery from harmful effects of the stress of rigorous training pre-taper.  Reactive oxidative species (ROS) and pro-inflammatory cytokines have been blamed for negative performance during over-training suggesting their role in taper dynamics.  Plasma levels of TNFα, IL-6, and IL-1β significantly declined after 3-weeks of reduced training in elite-level cyclists (Farhanimaleki, zehsaz & Tiidus 2009).  Interestingly, significant performance improvement on a 40 minute time trial was seen as early as 1 week into the taper and improved further after 3 weeks suggesting that anti-inflammatory effects of a taper may be more influential in longer tapers, while other mechanisms may contribute early on.

To date, ROS, unlike pro-inflammatory cytokines, have not been shown to be significantly altered during a taper. Although a 60% load reduction taper has been shown by Vollaard, Cooper, and Shearman (2006) to improve time-trial performance, training stress did not affect resting or exercise-induced ROS markers; oxidatively modified heme, total glutathionine, oxidated or reduced glutathionine. Hence, Vollaard et al. proposed that ROS itself does not directly negatively affect performance.

Muscle adaptations could also explain peak performance after a taper.  A 3-week taper induced a 7% increase in Myosin heavy chain (MHC) IIa fiber diameter, 11% increase in peak force a 9% increase absolute power concurrently with a 3% improvement in 8k cross country performance (Luden, Hayes, Galpin , Minchev, Jemiolo, Raue , Trappe, Harber, Bowers & Trappe, 2010). Transcription markers for genes involved in Type IIs fiber remodeling responded uniquely to the tapered training suggesting a myocellular basis for performance enhancement during reduced training.

Although not reviewed here, other possible contributions to adaptive affects of tapering on performance improvement include but are not limited to alterations in endocrine balance, neuromuscular adaptations involving running efficiency, and psychological recuperation (Lin and Chang, 2008).

Discussion

In the past few years quite a bit of research has attempted to discern the optimal training practice to time peak performances during the championship portion of a competitive season for distance athletes.  Most of the research agrees that reducing volume around 50% progressively over a week or two allows for the most improvement in running performance.  This is a practical finding that can be implemented at the end of a season when athletes shift their focus to competitive performance outcomes.  This strategy, however, should only occur after a solid base of training volume and intensity has been built since greater gains should be expected for an overall greater reduction in volume while continuing sufficient intensity.  It is likely that in untrained athletes progressively increasing training load would continue to provide performance improvements without the previously prescribed taper.

Further research on taper could begin to sort out the specificity in taper protocols based on the nature and duration of previous training, the athlete’s gender and age, and the length of the championship season. For instance, coaches and trainers may be interested in how to tailor a taper strategy that to fit their top-7 varsity athletes for a championship season that goes later into the season than the rest of their team, or how to use different strategies for athletes whose volume may already be low due to injury or sickness. Another thing to take into account while trying to alter training to peak for championship races, is how to implement these strategies while traveling to a national or international course. What effects might jetlag, long bus rides, or climate changes have on physiological adaptations just prior to desired peak performance?

As much as it would be ideal to have a completely objective protocol for implementing effective tapered training, like most areas of training, individual psychological response to specific strategies may have a considerable affect on performance outcomes. Experience tells us that many runners are likely to get impatient during tapers and fear that they must be losing fitness.  On the other hand, reduced training might induce a mental recovery from a rigorous training schedule and allow time and energy to be spent on preparing for the big competition. Realistically, coaches and athletes must learn through trial and error what works for them in certain situations.  They may then decide to error on the side of beginning to detrain but being 100% rested, or on the side of not being fully recovered but being sure to maintain their previous fitness. It may be important to weigh which option has more risk, and which has more payoffs and make a decision based on the athlete and the situation and their performance goals.

            Finally, this review shows there is still disagreement on what physiological adaptations contribute most to performance during a taper.  It is very likely that a combination of aerobic efficiency, anti-inflammation, muscle recovery, and a host of other changes account for this improvement. A better understanding of the physiological mechanisms behind training stress and recovery adaptations could help sort out the main contributors to a taper-induced performance enhancement. This knowledge would better inform practical applications in a variety of individuals and training circumstances.

Conclusion

            The research suggests that a standard protocol for a distance running taper involves a 40-60% progressive reduction in training volume, while maintaining training intensity and duration after a training period of 6-8 weeks. The physiological adaption to this reduction likely involves both attenuation of physical stress and inflammatory markers, and adaptive benefits after recovery such as muscle strength and hematological efficiency. Utilization of this protocol will likely increase an athlete’s odds of improving their performance in championship meets. The challenge remains, however, how to most efficiently taper so that improvement is more pronounced than an opponent’s. More research in taper training for optimal performance is warranted.  Specificity of tapers for individual athletes still remains an art.