INDEX


This column features short items about sport research in progress or in print, highlights of recent or upcoming conferences, hot topics on mailing lists, and anything else of interest to the sport-science community. Content can range from ground-breaking to gossipy. Send a paragraph or two to ferret=AT=sportsci.org. Items will be edited and bounced back to you for approval.

Nov-Dec
1998:

Performance Gene Discovered · Skeleton In The Freezer · One Set or More? · What's Worth Monitoring?

PERFORMANCE GENE DISCOVERED
     To be a top athlete you need the right genes. Sure, but until this year, no-one knew what those genes were. Now one has been discovered. It's called the ACE gene, because it codes for the enzyme that activates the hormone angiotensin--ACE is short for angiotensin converting enzyme.
     A group working in London knew that ACE is active in muscle tissue, where it regulates blood flow, so they figured it might have a role in endurance performance. They knew that the gene comes in two forms--I (for insertion) and D (for deletion)--so they did a study to find out if endurance athletes are more likely to have one or other form. The athletes they chose were elite mountaineers who could ascend above 7000 m without oxygen. Bingo! The I form was much more prevalent amongst the mountaineers than in the general population. What's more, the mountaineers who could go to the highest altitudes without oxygen had two copies of the I form (one from mom and one from dad). The researchers then showed that the I form of the gene produced a greater response to strength-endurance training in army recruits: after a 10-week training program, time to exhaustion in a weighted elbow-flexion exercise lasting 2 min increased by only 6% in the recruits with two copies of the D form, by 21% in those with an I and a D, and by 66% in those with two Is. The findings were published in the May 21 issue of Nature (Montgomery et al., 1998). Two months later an Australian group reported that the I form of the ACE gene was much more frequent amongst elite rowers than in the general population (Gayagay et al., 1998).
     Ferret can think of several important implications. First, athletes in endurance sports will show a better response to training if they have two copies of the I form of the ACE gene, so it won't be long before talent identification includes DNA testing. Will that be any different from selecting on the basis of maximum oxygen uptake? Secondly, other genes predictive of athletic potential will soon be discovered, but no gene will ever substitute for hard training, good coaching, and good sport-science support. Finally, sport scientists doing training studies with endurance athletes should think seriously about getting their subjects DNA tested, because the presence of the I form will help explain individual differences in the response to training.

Gayagay, G., Yu, B., Hambly, B., et al. (1998). Elite endurance athletes and the ACE I allele - the role of genes in athletic performance. Human Genetics, 103, 48-50.

Montgomery, H. E., Marshall, R., Hemingway, H., et al. (1998). Human gene for physical performance. Nature, 393, 221-222.

For another aspect of the impact of genes on sport performance, see the item on African genes in the July-August issue of Ferret.

Contributed by Will Hopkins.


SKELETON IN THE FREEZER
    If Professor Roald Bahr of the Norwegian University of Sport has his way, that skeleton would take the form of an extra blood sample drawn from athletes during testing for illegal but currently undetectable substances such as injected erythropoietin (EPO). The idea is to create a so-called C sample.
    Currently, cross-country skiers and professional cyclists in theory give two blood samples: the A sample, which is analyzed immediately, and the B sample, which serves as a verification sample in the event of an initial positive. Bahr suggests that a third sample should be drawn and deep frozen immediately for later analysis when new, more advanced detection techniques are developed. He argues that the increased threat of being retroactively caught for doping months or even years later would serve as an added deterrent against the use of EPO and other substances that currently cannot be detected in a judicially air-tight manner. Today, a "positive" EPO test is based on hemoglobin concentration or hematocrit being over a pre-defined limit. Because of the uncertainty of this indirect method, athletes testing positive are merely denied participation until they are back to a legal level.
    Olympic gold medalist cross-country skiers Thomas Alsgaard and Vegard Ulvang (retired) approve of the idea of a C sample. According to Alsgaard, "All methods that scare are positive. A lot of substances are currently used that the doping-hunters don't even know about." Ulvang is now engaged at the international administrative level by FIS, the International Ski Federation. He adds, "A very clever suggestion. This can scare someone from doing something illegal." The suggestion has also drawn support from the Norwegian cycling community, including newly-crowned U-23 world time trial champion Thor Hushovd. The suggestion is currently under political and judicial evaluation by the Norwegian Sports Federation.
    Meanwhile, international steeplechaser Jim Svenøy also welcomes a C sample, but points out the question is moot within track and field. The International Amateur Athletic Federation does not employ blood testing at all, despite suspicions that EPO is widely used among distance runners.

Contributed by Stephen Seiler.


ONE SET OR MORE?
     For most folks a session of strength training at the gym means a circuit of exercises repeated for three or more sets. According to all the text books, performing multiple sets of an exercise gives you greater gains in strength than performing a single set of the exercise. But in a recent review Carpinelli and Otto conclude that several sets of a strength-training exercise are no more effective than a single set. Their method requires you to choose a weight which you literally fail to lift somewhere around the tenth repetition. All you do in your workout for each exercise is one such set. It's a style known as high-intensity training, or HIT.
     Subscribers to the Sportscience mailing list will recall a vigorous debate about this style of training in July last year. It transpired that the devotees of HIT are widely regarded as a commercially motivated fringe group whose ideas fly in the face of experience and objective evidence. Ferret is now concerned that some of their ideas will gain legitimacy from this review, which is deeply flawed. In particular...
  • The gains in strength in almost all of the studies reviewed by C&O are too small. For example, they cited a study by Stowers et al. (1983) showing gains of 15%, 20% and 27% for 1 set, 3 sets, and a periodized training protocol respectively. Stowers et al. suggested that significant differences are more difficult to produce when using small muscle mass exercises. More recent evidence also supports this view (Stone et al., 1991,1998). Multiple sets employing exercises that involve greater muscle mass produce gains equaling 100-170% or more in previously untrained subjects (e.g., Fiaterone et al., 1990; Morgan et al., 1995; Nau et al., 1998). Somehow the comparison studies in the C&O review have been loaded against multiple sets, possibly by restricting the review to studies of smaller muscle mass. (Incidentally, C&O commented that there were no differences between the groups in the Stowers et al. study, but that is clearly not so.)
  • Most of the studies in the review are of untrained subjects, who gain strength with any form of training in programs of 12 weeks or less. Most of the gains stem from neural factors rather than muscle hypertrophy (Abernathy et al., 1996; Hakkinen, 1985, 1994; Stone, 1993). But when it comes to prolonged training programs--well beyond the 12-week protocol typical of the studies reviewed by C&O--recent and other studies not included in the review favor multiple sets for both well trained and sedentary subjects (e.g., Marx et al., 1998).
  • In any case, gains in strength are only one aspect of strength training. The majority of gym-going customers want to LOOK strong. There is little doubt that multiple sets produce bigger gains in muscle hypertrophy than single sets, despite C&O's claim to the contrary.
  • Injury and overtraining are known hazards of weight training, especially if it does not employ periodization. Both appear more likely when training to failure, whether using one set or multiple sets. In a recent review Stone et al. (1998) noted that training to failure produces considerable fatigue. Fatigue increases the risk of injury, probably through changes in movement patterns. Additionally, the work of Nimmons et al. (1995) suggests that training to failure and beyond (e.g., forced reps) on a consistent basis can lead to overtraining.
     Ferret's advice: keep doing multiple sets, periodize your training intensity, and watch for a thorough objective review.

Selected References:

Carpinelli, R.N. & Otto, R.M. (1998). Strength training: single versus multiple sets. Sports Medicine, 26, 73-84.

Kraemer, W.J. (1997). The physiological basis for strength training in American football: fact over philosophy. Journal of Strength and Conditioning Research 11, 131-142.

Kraemer, W.J. et al. (1997). Effects of single versus multiple sets of weight training: Impact of volume, intensity and variation. Journal of Strength and Conditioning Research 11, 143-147.

Marx, J.O. (1998). The effect of periodization and volume of resistance training in women. Medicine & Science in Sports & Exercise 30(5), S164 (Abstract 935).

Sanborn, K. et al. (1998). Performance effects of weight training with multiple sets not to failure versus a single set to failure in women: A preliminary study. Presentation at the International Symposium on Weightlifting and Strength Training, Helsinki, Finland, November 10-12, 1998.

Retrieve the messages on the Sportscience list for July 1997 by sending get sportscience log9707 to listproc=AT=stonebow.otago.ac.nz, then search for HIT in the files you receive.

Contributed by Fred Hatfield.


WHAT'S WORTH MONITORING? 
    A friend of the Ferret posed this question recently on the Sportscience mailing list. His original question was focused on lab tests of performance. He doubted whether these tests were precise enough to track the small changes in performance that matter to an elite athlete. Field tests, time trials, or competitive performances might be the only things worth monitoring.
    He has combined the original question and the replies into a single document, which you can access from this link. Those who contributed material have agreed to the publication of their messages. Here is a summary of the most important points, drawn partly from the replies and partly from further discussions with coaches and sport scientists.
  • Regular systematic monitoring by a dedicated team of support personnel is a key component of some successful high-performance programs.
    • Performance itself needs to be monitored, but so do any factors that might impact even indirectly on performance.
    • Depending on the sport, these factors include agility, anthropometry, biomechanics, musculoskeletal status, nutrition, physiology, psychology, and skill.
    • Where appropriate, these factors need to be measured in sport-specific ways.
    • Rapid, direct communication between athlete, coach, and sport scientists will help in the identification and prioritization of strengths and weaknesses.
  • The ability of a test to track changes in an athlete's performance depends on the variability in the athlete's performance between tests. If this variability is greater than the variability in the athlete's performance between competitions, the test won't be able to track small but valuable changes in performance.
    • For endurance runners, several measures of anaerobic-threshold speed derived from blood lactates in an incremental test have a typical variability between tests of only ±1.5% (Pfitzinger and Freedson, 1998), which is similar to the variability in competitive endurance performance of world-class athletes. The anaerobic threshold is therefore well worth monitoring. Another advantage of most anaerobic-threshold tests is that the athlete does not have to make a maximal effort.
    • Non-competitive maximal lab tests or field time trials probably have more variability between tests than the anaerobic threshold, so they aren't as useful.
    • In one lab the variability in maximum oxygen uptake between tests is ±2.0% (Rivera-Brown et al., 1995). In most other places it ranges from ±3 to ±6%, or about ±2-4 ml/min/kg. This test is therefore precise enough to identify athletes with endurance potential. Regular monitoring of maximum oxygen uptake with a standardized protocol and equipment may also help delimit moderate-large changes in an athlete's endurance conditioning. In this respect it may complement peak power and anaerobic threshold derived from a standardized incremental test.
  • An increase in the anaerobic threshold by itself could indicate an improvement in fitness or the onset of overtraining. But other measures will clarify the situation (e.g. peak heart rate, peak lactate, effort, body mass, skinfolds, mood state) and may even give you advanced warning of overtraining.
  • There is still no worthwhile published practical hormonal or other blood test that can be used to diagnose overtraining, let alone monitor for incipient overtraining (Urhausen et al., 1998).
  • But studies of overtraining and performance enhancement are usually performed over a restricted time frame, with insufficient pre- and post-testing to delimit individual differences in the response to changes in training or other intervention. When individual athletes are monitored over several years, these individual differences may become apparent to the coach and sport scientist, who can then optimize training and other treatments for the individual.
  • Even if some lab tests aren't particularly reliable, the interactions between athlete, coach, and sport scientist during administration of the tests are worthwhile. Regular testing also motivates the athlete.
  • Through experience or formal research, some sport scientists have found new methods to monitor athletes. Some of these methods may be too valuable for publication, but in general they probably confer only a small advantage to the athletes lucky enough to be monitored by them. Far more important is regular systematic monitoring of the basics, which any well-trained sport scientist can do.

Pfitzinger, P., & Freedson, P. S. (1998). The reliability of lactate measurements during exercise. International Journal of Sports Medicine, 19, 349-357.

Rivera-Brown, A. M., Rivera, M. A., & Frontera, W. R. (1995). Reliability of VO2max in adolescent runners: a comparison between plateau achievers and nonachievers. Pediatric Exercise Science, 7, 203-210. [Coefficients of variation calculated from correlations and standard deviations.]

Urhausen, A., Gabriel, H. H., & Kindermann, W. (1998). Impaired pituitary hormonal response to exhaustive exercise in overtrained endurance athletes. Medicine and Science in Sports and Exercise, 30, 407-414.

Contributed by Will Hopkins.
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