Many of us need to put down our TV remote control units and pick up our tennis rackets, according to a new study by a Brigham Young University physical education professor.

The more television we watch, Larry Tucker's research found, the less likely we are to be physically fit.Tucker tested nearly 9,000 male and female employees from 75 companies nationwide using a questionnaire that detailed demographic and lifestyle information. Participants also underwent a step test and a skin-fold test that measured physical fitness and body fat.

He then compared fitness levels with reported levels of television viewing, ranging from frequent (more than four hours a day) to infrequent (less than one hour a day).

"As television viewing time increased, the share of physically fit adults decreased significantly, from 19 percent to 9.5 percent," Tucker found. "Frequent television watchers showed the lowest level of fitness, followed by moderately frequent watchers, then moderate viewers, and lastly infrequent TV watchers.

"Compared with infrequent TV viewers, the number of physically fit adults was 27 percent lower among moderate viewers, 41 percent reduced among moderately frequent viewers, and 50 percent lower among frequent television viewers," he said.

The relationship between too much TV and too little fitness remained basically the same after adjusting for age and sex. It increased when Tucker factored in variables such as body fat, hours worked per week and smoking.

"In short, frequent television viewers are most often male, more likely to smoke, more obese, more sedentary and work fewer hours than those who viewed less television," said Tucker. He published his findings in a recent issue of the Research Quarterly for Exercise and Sport.

In earlier studies, Tucker found a similar relationship between television viewing and physical fitness in teenagers as well as a strong link between TV watching and obesity in men.

"As television viewing time increases, physical activity tends to decrease. As physical activity declines, physical fitness tend to decline. As physical fitness declines, attraction to passive recreation such as television watching tends to increase," he said.

The meaning of the research is clear to Tucker. "If a causal relationship exists between TV viewing and fitness, most adults - especially those in poor physical condition - should reduce the time spent watching television," he said.