I remember reading somewhere that prepubertal runners have essentially unlimited aerobic capacity, due to the relative size of their body compared to their ability to take on oxygen, and that puberty changes this. Who here has done any research on this or can help me find the literature on it?
I'm reading a book right now titled Training For Young Distance Runners by Larry Breene and Russ Pate. The book is geared specifically toward training runners aged 12-18. They discuss a lot of the effects of growth and maturation in the first chapter. It's a good book if you coach HS or Jr. High distance runners.
http://www.humankinetics.com/products/showproduct.cfm?isbn=087322406X
That should be Larry GREENE, I can't type
Puberty has a huge impact on athletic performance. Lets look at the development of a human being.
Age 0-6ish: coordination and body awareness
6-12ish: neurimuscular development (in my opinion the most important time for sport spicific development)
Puberty: The body makes the switch to being basicly what we will remain like for the rest of our lives. Boys get stronger. girls are able to have children. this is where we see boy and girls start to really become different as related to physical performance. Boy simply get stronger via testerone. It's much harder for girls. Estrogen has profoundly different effect on the human body.
post puberty (15ish) to 21ish Body development, solidifaction, and the final growing period.
21ish to 32ish (men) 37ish (women) is the strongest period the body can get stronger than ever before and withstand more abuse than ever.
I'll stop there.
Puberty will greatly change the physical capabilitys of any kid. this is where we can most easily see who will be the best athletes. Boys is easy. Girls present a whole slew of effects. With the boy the strongest will pull away from the rest but usually they were stronger to begin with. With girls you will se a complete reshuffleing of the top performers.
I'm not entirely sure why this is and there needs to be more research done on the effects on athletic performance.
That being said, kid gloves (pardon the pun) need to be worn when dealing with any athlete durring puberty. After the change, esp in girls, they may not be as good as they were before as compaired to the other kids and need all the support they can get for whetever direction they want to go.
More ramblings by
LaWoof
Very good article for information
http://www.alliedhealthrehab.com/Safety%20Zones/Index_safety_Zones.htm
Article primarily geared toward young female runners
http://www.pressdemocrat.com/running/03stamps.html
Another article posted by "Ears2You" a while back:
Taken from the Albany Times Union:
Girls sometimes hurt by early success
Young elite distance runners often suffer from injuries, burnout
By MARK SINGELAIS, Staff writer
First published: Tuesday, May 27, 2003
Saratoga Springs' Erin Davis was a running phenom by age 15, getting profiled in the New York Times and becoming the only freshman to win the national cross-country championship.
That early success was the worst thing that could have happened to her, according to her coaches, Linda and Art Kranick, because of the unfair expectations that followed.
"When she crossed the finish line first (at nationals), Art and I were ecstatic for about 10 minutes," Linda Kranick said. "Then we said, 'This is terrible. What can she do to top this? If you don't win it all four years, (people think) it's a failure.' "
Davis was far from a failure, winning four straight Federation cross-country titles and being named Runner of the Decade for the 1990s by the state sportswriters association.
But Davis never fully realized the promise she showed in winning the Foot Locker nationals in San Diego in 1993. Now 24 years old, Davis no longer runs competitively, her career having ended in a flurry of injuries at Penn State University.
"Everybody envisions themselves running in the Olympics," Davis said. "I just didn't realize later on down the road that I would have so much wear and tear on my body that running wasn't that fun anymore."
In the world of women's distance running, it's fairly common to find top performers in the lower grades with seventh-grade champions not unheard of. There will be many adolescent girls competing in the Freihofer's Run for Women, the 5-kilometer national championship held Saturday in Albany.
But early success doesn't always foreshadow sustained excellence. Some of the better runners tend to tail off as they reach adulthood.
Sometimes, it's because of the type of emotional strain that Davis faced. Linda Kranick said some girls simply find other interests.
Doctors add that some elite girls overtrain, which increases the risk of injury because their bodies mature differently than boys' and aren't yet prepared to handle the physical pounding.
Dr. Angela Smith, an orthopedic surgeon who specializes in pediatric sports medicine at the Children's Hospital in Philadelphia, said some female runners excel at a young age because they haven't reached puberty.
"They have maximal power at that age of 12, 13 or 14," Smith said. "As soon as they hit puberty, that balance is no longer there. Their percentage of normal body fat increases, and they lose that temporary advantage."
Smith said that moderate running is fine for young girls. But as they go through growth spurts, Smith said, there are serious risks that go with intense training. Their bones and muscles haven't thickened yet, which can lead to stress fractures and other injuries.
Smith said she recently saw a high school team in the Philadelphia area that has seven of its 11 girls unable to finish the season because of injuries.
"That's obviously the extreme," she said.
Smith quoted studies -- not specifically geared to runners -- that say that girls who participate in a single sport year-round for more than 15 hours a week are more likely to suffer injuries.
Dr. Oded Bar-Or, of McMaster University in Hamilton, Ontario, told the New York Times in an interview last month that the beginning of the menstrual cycle can hinder a female runner's performance for a time.
"Girls gain fat, and in some cases there is a decrease in iron stores and hemoglobin level of the blood," said Bar-Or, a leading researcher in children's exercise and nutrition. "Fitness level in girls, their maximal oxygen uptake, decreases after age 12 or 13."
Davis, the ex-Saratoga star, was quick to point out that she was relatively healthy in high school. She said her highest mileage then was 40 to 50 per week, under the Kranicks' strict supervision, and she rarely suffered worse than a hamstring pull.
"When I had a growth spurt, I was very tired," Davis said. "I had one year when I wasn't running as fast and I needed a break, at the end of 10th grade and most of 11th grade. I consider that my burnout year."
Still, Davis finished fourth in cross-country nationals as a sophomore and seventh as a senior.
Davis said it wasn't until she reached Penn State that she suffered significant setbacks, including a lower back injury. She said that the Penn State coaching staff didn't give her the type of hands-on attention the Kranicks did.
"Actually, I hated college running," Davis said.
Linda Kranick said that reports of runner burnout are overstated.
"It's kids making other choices," she said. "Kids tend to switch from activity to activity, sport to sport. How many adults change jobs?"
Averill Park's Jen Fazioli, 22, was a contemporary of Davis who competed at the University of Colorado. She's now training for the Olympic marathon trials next April in St. Louis.
Fazioli, who began running when she was 10, said she had two stress fractures in high school because of a growth spurt.
She said she feels good now but will probably give up competitive running after next year.
"It's hard to motivate yourself all the time," she said. "I've done it so long."
Davis, meanwhile, hasn't run competitively since dropping out of her last college race, the Big Ten championships, two years ago. Her knees bother her, but she ran for fun in the Corporate Challenge last Thursday in Albany.
"In the middle of the race, I told myself that I don't miss it," she said.
At the other end of the spectrum is Kirsten Hornbeck, a Saratoga senior, who will run with several teammates in the Freihofer's on Saturday. Hornbeck, who will compete at Columbia University next year, sounded very much like someone who still loves the sport.
"I enjoy the competition, and the training is worth it," she said. "It's just fun to get out there and see what you can do."
That's great stuff. The quote from Dr. Bar-Or is the one I remember. It suggests to me that the upside for a runner like Ari Lambie is quite good, given that she looks physically mature and is just now coming into quality form.
bump. let's leave the personal saga of Briana J. out of this and get to the science. who's got more to say?
Training for Young Distance Runners, Larry Greene and Russ Pate, p.8
"Many sport scientists agree that youths are naturally gifted with physical fitness for endurance activity. In laboratory tests, untrained youths have very high levels of maximal oxygen consumption or VO2max, a measure of the body's aerobic, or oxygen-utilizing, capacity. Pound for pound, an untrained 12-year-old is able to utilize more oxygen than most 20-year-olds who exercise regularly! These high levels of VO2max in youths are probably a product of age and high levels of everyday activity in games and sports.
While youths have a naturally high aerobic capacity, they are less fit to exercise under anaerobic conditions, or when oxygen is in short supply in the muscles - as in an all-out 400-meter sprint. Anaerobic fitness is related to the individual's maturational status. In fact, the ability to perform muscular work without oxygen improves dramatically following puberty. Thus, prepubertal youths respond well to aerobic, or moderate-intensity, running, but they are limited when doing anaerobic, or high-intensity, running.
Poor running economy, or efficiency, also limits the young athlete's physiological fitness. Young runners tend to waste energy as a result of flaws in technique."
From Essentials of Exercise Physiology, William McArdle, Frank Katch, Victor Katch, p.132
Absolute Values
The maximal oxygen uptake expressed in liters per minute rapidly increases during the growth years. Longitudinal studies of children and aerobic power have been few. The available data indicate that the absolute max VO2 ranges from about 1.0L/min at age 6 years to about 3.2L/min at 16 years. Average max VO2 in girls peaks at about age 14 and begins to decline thereafter. At age 14, the differences in max VO2 (L/min) between males and females approximates 25%, and will reach 50% by age 16 years.
Relative Values
When expressed relative to body mass, the max VO2 remains constant at about 53ml/kgmin between the ages of 6 and 16 for boys. On the other hand, relative max VO2 gradually decreases with age in girls from 52.0ml/kgmin at age 6 to 40.5ml/kgmin at age 16 years. The most commonly offered explanation for the discrepancy in relative max VO2 between boys and girls as they advance in age is the relatively greater accumulation of body fat in females.