June 1, 2009 A study by Indiana University researchers found that athletes' elevated or heavier breathing at sea level immediately following high-altitude training accounts for a substantial amount of the gains from the high-altitude training. The heavy breathing is temporary, however, said Robert Chapman, lecturer in IU's Department of Kinesiology, and makes a case for why athletes should consider giving themselves one week to 10 days at sea level before a major competition.
Elite endurance athletes, such as runners, swimmers and triathletes, often train at high altitudes for a month or more because the body creates more red blood cells to adapt to the lower oxygen content of the air. An increase in red blood cells can help athletes by shuttling more oxygen to fuel muscles when they compete nearer to sea level.
Chapman said their study, however, found that the elevated breathing athletes experience temporarily when returning to sea level can account for 10 percent to 20 percent of the body's increase in its ability to consume oxygen. If athletes factor this time in before their competition, the heavy breathing would go away and they still would likely have the extra red blood cells, unless they wait too long.
"It's a matter of balance," said Chapman who also heads Team Indiana Elite, a group of professional distance runners based in Bloomington.
The study "Maximal Oxygen Consumption Changes After Altitude Training: Role of Ventilatory Acclimatization," was presented at the AMSC conference during the Altitude and Hypoxia: Training and Performance Session Friday morning. Co-authors of the study include lead author Daniel P. Wilhite, Abigail S. Laymon, James M. McKenzie and Elisabeth A. Lundgren, all from Indiana University.
Other studies from Chapman and his colleagues include the following:
- The researchers examined whether athletes become more economical because of high-altitude training -- consuming less oxygen at any given speed once they return to sea level. Chapman said the researchers did not see any improvements. Economy was the same or worse, he said, in part because of the elevated breathing the athletes experienced when they returned to sea level. The study, "Running Economy Changes After High Altitude Training: Role of Ventilatory Acclimatization," was presented during the Altitude and Hypoxia: Training and Performance Session on Friday morning. Coauthors of this study are Lundgren, Wilhite, Laymon, McKenzie and Chapman.
- Researchers found that the use of high-speed accelerometers, which can record every footstep an athlete makes down to the millisecond, can be an accurate coaching tool. Chapman said coaches have used video and force plates to measure and characterize certain components of running mechanics. The equipment cannot follow an athlete's every move. Accelerometers are lightweight and can be attached to a runner's shoe, capturing each foot fall -- even if the sprinter's foot spends only 8 milliseconds on the ground. Chapman said the data can be useful to coaches in a variety of ways, such as learning how athletes' gait change when they fatigue and even predicting distances athletes might be best suited to run.
The study, "Measurement of Gait In Elite Distance Runners Using Fast Sampling Accelerometers," was presented in the Gait Analysis II Session on May 30. Co-authors of the study include McKenzie, Wilhite, Laymon and Lundgren. This study was supported by a grant from the High Performance Division of USA Track and Field.
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