But 'Limited Ability' to Increase Speed and Agility, Follow-Up Study Finds

Newswise — Philadelphia, Pa. (August 31, 2011) – During the course of a college football career, players show substantial gains in size, strength, and power—but less so in speed or agility, reports a study in the September issue of The Journal of Strength and Conditioning Research, official research journal of the National Strength and Conditioning Association (NSCA). The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

"Appropriately designed resistance training programs do appear to result in significant strength and body mass gains throughout the football career of NCAA Division III athletes," according to the new study. The lead author was Jay R. Hoffman, Ph.D., CSCS*D, of University of Central Florida, Orlando.

In College Football Players, Strength Can Be Increased Over Time …Dr. Hoffman and colleagues monitored a wide range of physical and performance variables in 289 Division III college football players throughout their four or five years of college football eligibility. (Some players had "redshirt" years in which they were eligible to practice but not play.)

Measures of size, strength and power, and speed and agility were obtained each year at the beginning of summer training camp. The goal was to determine which physical performance characteristics are—and are not—amenable to improvement through rigorous athletic training programs.

The data showed significant increases in player size and strength from freshman to senior year. The players' body mass increased by an average of 21 pounds. Body mass increased for both backs and linemen. However, the size gains were significant in the second year for backs, but not until the fourth year for linemen.

Along with increased size came significant increases in strength. From the first year to the fourth or fifth year, bench press strength increased by 31 percent while squat strength increased by 36 percent. Aerobic conditioning also improved, as shown by lower scores for fatigue on a standard line drill.

…But Limited Ability to "Transform a Slow Athlete to a Fast One"However, there were only small improvements in speed or agility—40-yard sprint time improved by an average of only 0.2 second. There was a small but significant improvement in vertical jump height: about two inches.

Strength gains showed a "biphasic" response, with a significantly greater increase in the last competitive year. The researchers speculate that some of these late increases might have resulted from the use of performance-enhancing drugs. (However, they emphasize that none of the athletes in the study had positive results on drug testing.)

Increasing strength, power, and speed are key goals of strength and conditioning programs for college football players. However, relatively few studies have tracked the effectiveness of training programs in increasing these physical performance variables across a player's athletic career.

The few previous studies of this issue have focused on football players in Division I—the highest level of competition. Those studies showed that the most improvement occurred in the first year or two of training. The new findings suggest a different pattern in Division III football players, with strength and power continuing to increase throughout a four- or five-year collegiate career.

This information may be useful to strength and conditioning professionals seeking to designs training programs that will maximize athletic performance. "Significant changes can be made during an athlete's career but...these changes are slow and may only become statistically significant after 3 to 4 years of training, Dr. Hoffman and colleagues write.

At the same time, the results suggest only minimal changes in speed and jumping ability—likely reflecting genetic factors that impact athletic potential. "Collegiate football players can become faster and jump higher, but the ability to transform a slow athlete to a fast one appears to be limited," the researchers conclude.


About The Journal of Strength and Conditioning ResearchThe editorial mission of The Journal of Strength and Conditioning Research (JSCR) is to advance the knowledge about strength and conditioning through research. A unique aspect of this journal is that it includes recommendations for the practical use of research findings. While the journal name identifies strength and conditioning as separate entities, strength is considered a part of conditioning. The journal wishes to promote the publication of peer-reviewed manuscripts which add to our understanding of conditioning and sport through applied exercise science. The JSCR is the official research journal of the National Strength and Conditioning Association.

About the National Strength and Conditioning AssociationThe National Strength and Conditioning Association (NSCA) is an international nonprofit educational association founded in 1978. The NSCA develops and presents the most advanced information regarding strength training and conditioning practices and injury prevention. Central to its mission, the NSCA bridges the gap between the scientist in the laboratory and the practitioner in the field. By working to find practical applications for new research findings in the strength and conditioning field, the Association fosters the development of strength training and conditioning as a discipline and as a profession

About Lippincott Williams & Wilkins Lippincott Williams & Wilkins (LWW) is a leading international publisher for healthcare professionals and students with nearly 300 periodicals and 1,500 books in more than 100 disciplines publishing under the LWW brand, as well as content-based sites and online corporate and customer services.

LWW is part of Wolters Kluwer Health, a leading global provider of information, business intelligence and point-of-care solutions for the healthcare industry. Wolters Kluwer Health is part of Wolters Kluwer, a market-leading global information services company with 2010 annual revenues of €3.6 billion ($4.7 billion).