Endurance Athletes: What is the Optimal Training Strategy?

One of the attractive aspects of the International Journal of Sports Medicine is the inclusion of a Training and Testing section. Papers in this section frequently deal with the complexity of determining the components of an effective training program for endurance athletes and designing field or laboratory tests to assess performance potential in response to a given training paradigm. Although the role of exercise and physical activity in the treatment and prevention of diseases such as obesity, heart disease, type 2 diabetes, and the metabolic syndrome, applies to large segments of the population, the study of factors that contribute to optimal athletic performance is an integral component of the exercise science field. Findings in athletes offer insight into effective exercise training practices that ultimately may be applicable to the general population. In addition, the extreme physiological adaptations evident in endurance-trained athletes represent a benchmark for comparison. While discerning the optimal training paradigm as well as an accurate method to determine the capacity for endurance performance remains elusive, recent work published in IJSM provides some insight into these areas.

Manipulating the training practices of endurance athletes is sometimes difficult due to the perception that the greater the intensity and volume, the more pronounced the physiological and performance gains. A recent paper by Faude et al. [6] compared a high-volume, low-intensity vs. a low-volume, high-intensity program in competitive swimmers. A variety of outcomes linked with performance (lactate threshold, 100 and 400 m times) indicated no significant differences between the two training protocols. These data lead to the conclusion that high training volumes have no advantage compared to high-intensity training comprised of a shorter volume. Mikkola et al. [8] reported that reducing training volume by 20% concurrent with the addition of explosive-type exercises enhanced anaerobic performance without impairing aerobic capacity in young distance runners; such an adaptation may be positive considering that the ability to sprint at the conclusion of a race could ultimately determine placing in a competition. Such findings are supportive of the concept that many physiological adaptations can be attained with lower-volume training of the appropriate intensity. However, as proposed by Atkinson et al. [1] a clinical trial based approach may ultimately provide the most comprehensive and definitive finding(s) in terms of effective training practices and thus should be considered.

In competitive athletes, a common fault with training is an overcompensation in terms of overload as opposed to not training sufficiently. This phenomenon is described by a variety of terms including staleness, overreaching, and overtraining. The criterion measurement for determining this state is a decrement in performance [4] [5]; however, it would be an obvious advantage to have a measurement that is indicative of the overtraining state prior to any loss in athletic potential. Coutts et al. [5] examined potential markers of overreaching in experienced, competitive triathletes and concluded that perhaps the most effective predictor was a questionnaire assessing the recovery-stress state [7] as opposed to physiological variables. In contrast, in athletes undergoing more resistance/power-oriented training alterations in the plasma testosterone to cortisol ratio, plasma glutamate, plasma glutamine to glutamate ratio, and creatine kinase exhibited significant changes with an overload period that were possibly linked with muscle damage and performance impairment [4]. Other work [3] indicated that urinary noradrenaline and the adrenaline/noradrenaline ratio may be indicative of training stress in elite swimmers.

Athletic performance is the criterion measurement when determining the efficacy of a training schedule. However, periodically assessing performance is often not a reality in endurance events such as the marathon where recovery time from the event itself would be substantial and possibly impair training for the subsequent competition. Another approach to monitoring the effectiveness of a given training approach in endurance athletes is to employ tests that are predictive of performance. Arriese et al. [2] reported that variables linked with body composition and blood lactate production/removal were relatively predictive in a homogenous group of marathon runners. Obtaining such indices and attempting to predict performance potential in response to a given training program would obviously be preferable to directly assessing performance at the marathon distance.

There is no time in the training schedule that is perhaps more critical than the period immediately preceding an important competition. A frequent practice among endurance athletes is to reduce training volume prior to such a competition in an incremental fashion known as a “taper”; this reduction in training volume, if performed correctly, induces numerous positive adaptations linked with enhanced performance. However, the taper schedule that induces the optimal gains in performance is not yet evident. Trinity et al. [9] examined the effect of tapers consisting of either high-intensity or low-intensity exercise in collegiate swimmers during the course of two competitive seasons. The high-intensity taper was superior to the low-intensity taper in terms of maintaining maximal arm power and, most importantly, swimming performance in these athletes.

In summary, recent findings can aid the sport scientist, coach, and athlete in delineating the components of an effective endurance training program, in terms of training volume and intensity [6] [8] as well as the characteristics of the period immediately prior to the competition known as the “taper” [9]. While determining athletic performance is the ultimate criterion for evaluating the effectiveness of a training program, there are selected measures that may be indicative of training stress [3] [4] [5] and/or training efficacy [2]. Utilizing such measures may be preferable to assessing endurance performance periodically particularly in longer endurance events where recovery time may be substantial (i.e. a marathon). However, additional research needs to be performed to refine training practices as well as provide accurate field and laboratory tests that can be used to predict performance.

J. A. Houmard

References

• 1 Atkinson G, Batterham A, Drust B. Is it time for sports performance researchers to adopt a clinical-type research framework?.  Int J Sports Med. 2008;  29 703-705
• 2 Arrese AL, Izquierdo DM, Galindo JRS. Physiological measures associated with marathon running performance in high-level male and female homogenous groups.  Int J Sports Med. 2006;  27 289-295
• 3 Atlaoui D, Duclos M, Gouarne C, Lacoste L, Barale F, Chatard J-C. 24-h urinary catecholamine excretion, training and performance in elite swimmers.  Int J Sports Med. 2006;  27 314-321
• 4 Coutts A, Reaburn P, Piva TJ, Murphy A. Changes in selected biochemical, muscle strength, power, and endurance measures during deliberate overreaching and tapering in rugby league players.  Int J Sports Med. 2007;  28 116-124
• 5 Coutts AJ, Wallace LK, Slattery KM. Monitoring changes in performance, physiology, biochemistry, and psychology during overreaching and recover in triathletes.  Int J Sports Med. 2007;  28 125-134
• 6 Faude O, Meyer T, Scharling J, Weins F, Urhausen A, Kinderman W. Volume vs. intensity in the training of competitive swimmers.  Int J Sports Med. 2008;  29 906-912
• 7 Kellman M, Kallus KW. Recovery-stress questionnaire for athletes: User Manual. Champaign, IL:Human Kinetics 2001: 35-64
• 8 Mikkola J, Rusko H, Nummela A, Pollari T, Hakkinen K. Concurrent endurance and explosive type strength training improves neuromuscular and anaerobic characteristics in young distance runners.  Int J Sports Med. 2007;  28 602-611
• 9 Trinity JD, Pahnke MD, Sterkel JA, Coyle EF. Maximal power and performance during a swim taper.  Int J Sports Med. 2008;  29 500-506

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