Research Review By Kevin Neeld©

Date Posted:

October 2009

Study Title:

Power Athletes and Distance Training: Physiological and Biomechanical Rationale for Change

Authors:

Elliott M et al.

Author's Affiliations:

Peak Performance Project, Santa Barbara, CA; Department of Biokinesiology, University of Southern California, Santa Barbara, CA.

Publication Information:

Sports Medicine 2007; 37(1): 47-57.

Background Information:

Power, defined as the product of force and distance over time, is fundamental to the majority of athletic movements, regardless of sport. As an example, sports like basketball and soccer that involve a lot of continuous low intensity movement are still characterized by brief periods of high-intensity rapid movements. Although not technically considered “power”, another relevant performance measure is the rate of force development.

Rate of force development differs from power in that power necessitates movement. In other words, pushing up against an opponent may result in no movement (and therefore no power since there is no distance in the equation), but will require significant amounts of force generation.

In order to best prepare athletes for the rigors of their sport, and to maximize their performance abilities, it is necessary to understand the sport-specific sources of energy production. Brief high power movements and rapid force generation rely primarily on phosphocreatine (PCr) and adenosine triphosphate (ATP), with glycogen/glucose providing energy for repeated efforts. The aerobic system is thought to be important in the resynthesis of PCr, which helps facilitate recovery.

Although a well-functioning aerobic system is undoubtedly important to athletic success, it is not necessary to develop the aerobic system using prolonged, relatively slow bouts of endurance exercise.

The purpose of this review was to discuss scientific evidence related to the effects of long, slow distance training on various physiological and performance measures of power athletes.

Pertinent Results:

  • A survey of NHL, NBA, and NFL strength and conditioning coaches revealed that many programs are still using VO2MAX and other prolonged aerobic tests, despite the scientific evidence that these sports primarily utilize anaerobic pathways.
  • Prolonged endurance exercise reduces the ability to produce force at high velocities.
  • Compared to strength training alone, combined strength and endurance training results in a significantly lower rate of activation (as measured by surface EMG activity in the first 500 ms of a contraction) and a lower amount of myofibrillar ATPase activity (an enzyme involved in splitting ATP in ADP and P, which is essential for rapid force production).
  • Long-term aerobic training results in a decrease in the absolute content of fast twitch muscle fibres (Type IIa and Type IIx), which results in a decreased ability to produce high amounts of force or produce force rapidly.
  • Compared to strength training alone, combined strength and endurance training results in a significant increase in total cortisol (a hormone with a catabolic effect on muscle) levels, possibly due to the excessive stress of adrenal activation. Interestingly, strength training alone has actually been shown to decrease cortisol levels.
  • Previous research has found no correlation between VO2MAX tests and anaerobic performance tests. A positive relationship between VO2MAX and athletic performance is confounded by the fact that successful athletes also have higher strength (bench press and squat) and lower body power (vertical jump) measures.
  • One group found that when the total amount of work was equal, continuous and interval training produced equivalent adaptations in aerobic capacity, but the interval training resulted in greater adaptations in anaerobic capacity and power output.
  • High intensity interval training will lead to similar increases in glycogen storage capacity as sustained distance training.
  • Compared to an aerobic training group, an interval training group lost 9x as much body fat (measured as the sum of 6 skinfolds), at least in part due to significantly greater activity of muscle 3-hydroxyacyl coenzyme A dehydrogenase, a market of Beta-oxidation. This occurred despite the interval training group burning less overall calories.
  • Use of aerobic exercise to facilitate recovery is, at best, questionable. Local increases in circulation resulting from blood vessel dilation can result from any form of activity, including shorter bouts of more sport-relevant movements.
  • Compared with controls, sprinters had a significantly increased compliance and elasticity of the tendon and aponeurosis of the vastus lateralis and medial gastrocnemius at high levels of force production, whereas long-distance runners had a significantly decreased compliance and ability to absorb energy.

Clinical Application & Conclusions:

This article detailed a plethora of arguments against the use of aerobic training in the programs of power athletes. It appears that aerobic training and combined strength and endurance training result in performance decrements for physiological and biomechanical reasons. In addition to the notable results presented above, there are a few important practical applications of this review:
  1. If active recovery is the goal, it may be more beneficial and sport-relevant to perform technique work in the gym or on the field/arena. The muscular contractions will result in the same physiological effect, but the total stress to the body will be reduced.
  2. When adding any conditioning (continuous or interval based) to an athlete’s training program, it is important to at least somewhat decrease the volume of the rest of their training. Maintaining training volume and adding conditioning (especially prolonged continuous conditioning) primes the body for overtraining.
  3. Aerobic capacity tests should not be used for anaerobic athletes (essentially most team sports). Testing is a form of emphasis and athletes frequently follow training programs geared toward improving test scores. High performance on aerobic tests has little relevance to performance during anaerobic athletic events. Also, physiology-based tests, such as VO2MAX tests, describe performance capacity more than performance ability. Taking this evidence together, it seems logical that aerobic performance (1-mile run, Cooper Test, etc.) and capacity (VO2MAX tests) tests should be replaced by anaerobic performance-based tests (Wingate, shuttle runs for time, beep tests, repeat sprint tests, etc.).

Study Methods:

This study was a narrative literature review – a common publication type for this journal and appropriate for this topic.

Study Strengths / Weaknesses:

The authors did not specify their search criterion for articles related to this topic, which represents a weakness of this study.

Additional References:

  1. Bell GJ et al. Effects of concurrent strength and endurance training on skeletal muscle properties and hormone concentrations in humans. Eur J Appl Physiol 2000; 81(5): 418-427.
  2. Hennessy LC, & Watson AWS. The interference effects of training for strength and endurance simultaneously. J Strength Cond Res 1994; 8: 12-19.
  3. Kraemer et al. Compatibility of high-intensity strength and endurance training on hormonal and skeletal muscle adaptations. J Appl Physiol 1995; 78(3): 976-989.