INTRODUCTION
The most accurate assessment of aerobic capacity is the direct measurement of maximum oxygen uptake (VO₂max) during a graded exercise test. However, despite its level of accuracy, direct measurement of VO₂max is primarily reserved for the laboratory setting because of the cost of the equipment, the need for trained technicians, and the inability to test large numbers of people at one time. For these reasons, a multitude of prediction tests have been devised to estimate VO₂max. Most prediction tests utilize a high percentage of total muscle mass and require approximately 6-12 minutes of continuous work. For the college population the 1.5-mile or 12-min run are commonly used to estimate aerobic capacity . The rationale for these tests is based on practicality, since large numbers of students can be tested at one time. Recently, however, the 9-min run has been adopted by many programs to evaluate aerobic capacity. If this shorter test can successfully predict VO₂max, the cardiovascular fitness of physical education classes could be estimated. Therefore, the purpose of this study was to determine the relationship of the 9-minute run to VO₂max for college men.

METHODS
Eighteen healthy college men (ages 19-23 y) enrolled in a fitness class volunteered to perform the 9-minute run and a VO₂max test. The order of the tests was randomly assigned. At least five but no more than ten days elapsed between the two tests to eliminate the effects of fatigue. For the 9-minute run, the subjects ran as far as possible in nine minutes on an indoor track (147-yd/lap). The track was divided into eight equal segments, and the sum of total laps and segments was used as the total distance travelled.

The VO₂max was determined using a multi-staged progressive VO₂max test on a treadmill (Bruce, Kusumi & Husmer, 1973). Energy expenditure for each subject was monitored using a SensorMedics 2900 (Dayton, Ohio) metabolic cart. Each subject was required three minutes to warm-up on the treadmill in order to get accustomed to the breathing apparatus and the treadmill. The test was terminated at volitional fatigue and evaluated by appropriate heart rate and respiration exchange ratio criteria (Bruce et al., 1973).

RESULTS
The subjects were typical of those enrolled in the fitness course (mean ± SD, height - 181.6 ± 7.8 cm, weight - 79.1 ± 11.2 kg). The average distance for the 9-minute run was 2300.4 yds (± 213.6 yds), with a range of 1875 to 2696 yds. The VO₂max averaged 51.0 ml/kg/min (± 6.3 ml/kg/min) and ranged from 39.3 to 61.5 ml/kg/min.

There was a significant correlation (r = 0.83) between the 9-minute run and VO₂max (p<0.05). The standard error of estimate was ± 3.6 ml/kg/min. The prediction equation to estimate peak VO₂ from the 9-minute run was:

VO₂max (ml/kg/min) = 0.024 Run Dist (yds) - 4.7

DISCUSSION
This pilot study supports the use of the 9-min run as a predictor of VO₂max in college men. While longer runs have historically been used to estimate aerobic capacity (Burke, 1976; Zwiren, Freedson, Ward, Wilke & Rippe, 1991), the distance run in 9 mins appears to be acceptable as an aerobic capacity predictor.

REFERENCES

• Bruce, R. A., Kusumi, F., & Husmer, D. (1973) Maximal oxygen intake and nomographic assessment of functional aerobic impairment in cardiovascular disease. American Heart Journal, 85, 546-562.

  
  

• Burke, E. J. (1976) Validity of selected laboratory and field tests of physical working capacity. Research Quarterly for Exercise and Sport, 47, 95-103.

  
  

• Zwiren, L. D., Freedson, P. S., Ward, A., Wilke, S., & Rippe, J. M.. (1991) Estimation of VO₂max: a comparative analysis of five exercise tests. Research Quarterly for Exercise and Sport, 62, 73-78.