Recent studies suggest that as many as half of all firefighter and EMS personnel line-of-duty deaths are the result of cardiac arrest — heart attacks — associated with the severe stress of their jobs. Similar studies show that many LODDS among law enforcement officers are associated with stress-induced heart attacks, as well.

Aerobic activity has been demonstrated to improve cardiovascular health, which in turn lowers the risk of heart attacks. The U.S. Border Patrol has developed a 10-point aerobics program it believes has reduced deaths related to cardiovascular disease among the officers who have faithfully participated in the program. In addition, there's evidence that by having officers participate in the aerobics program and thus improve their cardiovascular health, the Border Patrol derives a savings from workers' compensation claims not filed as well as from sick leave not taken.

Before officers can begin the Border Patrol aerobics program, they must undergo a comprehensive screening, including a coronary artery disease risk assessment. (See CAD Risk Assessment, page 54.) Also, if an officer is at risk in a major category — high blood pressure (greater than 140/90), high blood lipids (over 200 total cholesterol), history of smoking, lack of physical activity or exercise — he or she must be cleared by a physician before participating in the program.

The “point” of the program

Exercise science research shows that an individual must burn approximately 1,000 calories per week in planned and purposeful physical activity to lessen his or her risk of dying from a cardiovascular incident. This equates to covering about 10 miles on foot per week because one person burns about 100 calories for each mile walked or run. The Border Patrol 10-point program therefore assigns one aerobic point to one mile walked or run, with the goal being to accumulate at least 10 points each week.

It's important to understand that walking or running burns about the same amount of calories per mile covered. The major difference, of course, is that a fit person might be able to run three miles in 18 minutes and then be done with aerobic fitness training for the day, while walking the three miles will take an hour. But either way, the net result is that the exercise session would burn about 300 calories.

It's also important to remember that the 10 points per week represent the minimal amount of aerobic physical activity necessary to gain the aerobic health benefit. The same research that noted the benefit of a 10-point program also showed a 12 to 15 points per week program was even better for health and fitness. The Border Patrol found 20 points per week, which translates to three points per day for six days and two on the seventh, seems to be optimal. An individual who attempts to jump to 30 points or more per week may become more aerobically fit than an individual earning only 10 aerobic points per week, but will be more susceptible to overextension injuries. Gradually increasing an aerobic workout is a more beneficial approach. Building the weekly point goal by 5- to 10% per week will help participants in the program avoid soreness and athletic injuries.

Activity comparisons

What if an officer wants to perform other aerobic activities? How do they compare to running or walking with respect to the aerobic point system of the program?

Cycling versus running

To equate the energy expenditure of cycling with running and or walking, you must consider the terrain, wind and weather. All other things being equal, an individual on a bicycle riding on a flat outside track or road in little or no wind will expend about the same amount of effort covering three to four miles as he or she would use covering one mile on foot. In other words, the ratio of cycling to running is about 3:1 or 4:1. If you normally run two miles a day and then switch to cycling, you will need to cycle six to eight miles a day for a similar aerobic workout. This conversion rate also assumes an equal physical effort made at both activities. In other words, if your two-mile run is made at 75% of your maximum pace, the conversion to cycling would assume a similar effort made at 75% of maximum pace.

Cycling also strengthens the quadriceps, the muscles in the front of the upper legs. But the hamstrings, or the muscles on the back of the upper legs, are stressed less by cycling than by running or walking. Therefore, it's important for individuals whose sole aerobic activity is cycling to also adopt a supplemental strength-building program that incorporates the hamstrings. Individuals who alternate walking with cycling gain the benefits of both aerobic conditioning as well as stronger the legs.

Swimming versus running

Unlike running and cycling, which provide aerobic activity benefit but strengthen only some muscle groups, swimming can provide a vigorous total-body aerobic workout. Swimming provides a full-body exercise and is an excellent conditioner for the cardiovascular system. Also, researchers have found that swimmers are injured less often while exercising when compared to runners.

Once again, to calculate how swimming equates to walking or running for the point system, we need to determine an appropriate ratio of swimming distance to running distance. Typically, an individual can run four times as far as he or she can swim in the same amount of time, so the swim to run ratio is about 1:4. In other words, one mile of swimming is approximately equal to four miles of running.

Again, it's important to remember these ratios assume these activities are done at about the same intensity of effort. If you swim at 60% of your maximum effort or exercise intensity, it is presumed you would use a ratio of distance covered while running at about 60% of maximum effort. It's also assumed that you are of reasonably equal proficiency at both swimming and running.

Running versus rowing and cross-country skiing

It's easy to compare running with cross-country skiing. The ratio here is about 1:1. There have been some dramatic changes in the way cross-country skiing is done today in that many good skiers are now adopting the skating approach, and the times for a set distance are faster as a result. However, the distances covered on skis are essentially the same distances that one could run with the same intensity of effort.

Another activity for comparison is that of rowing. One can cover half the distance running as rowing in the same amount of time, so the run-to-row ratio is on the order of 1:2. A rower should be able to cover twice the distance as a runner.

Other aerobic exercise

Many firefighters and EMS personnel will find it easier to work out indoors to be near their apparatus if a call comes in. The newer treadmills and exercise bikes are good for indoor exercise and are quite good in making accurate estimates of the mileage covered by an individual while exercising. Individuals should think of what kind of mileage they would do on a track outdoors, having regard for the pace and intensity of effort. If a person can run a 7- to 9-minute mile outdoors with about 75% to 85% effort, then this should be the same effort put in on the treadmill indoors.

With newer exercise machines like elliptical trainers, it might be harder to quantify the aerobic component of the workouts. Again, the exerciser should use the time and the intensity of effort rule to determine the amount of calories burned with the exercise session. The calories printed out on the screen of the exercise device should be in the range of those that the exerciser estimates for the workout. The aim should be to burn at least 250 to 350 calories burned as a minimum aerobic workout; the exerciser might then turn to another aspect of the workout, such as strength training.

Another aspect to consider with exercising on a stationary bike, treadmill or other device is that one can accumulate exercise time during each day for any aerobic exercise. Until recently, most exercise scientists were of the opinion that for physical activity to be of benefit, it had to be intense with a certain regard for heart rate and maintained for at least 30 continuous minutes. Today, aerobic exercise research shows the benefits are just as significant if the exercise minutes are accumulated throughout the day. For example, you can exercise in the morning during a 15-minute break from work, do another 20 minutes at lunch, and then another 15 minutes in the afternoon — the health benefit derived is the same as if you had exercised continuously for 50 minutes.

We're learning that the cardiovascular and health benefits of the physical activity aren't limited exclusively by heart rate. To become fit, you must consider heart rate, but for all beginning exercisers it's better to go for the distance (duration and/or time) and accumulate aerobic points. Once a healthy aerobic exercise routine has been established, individuals then may want to try for an advanced level of fitness by increasing the intensity of effort and increasing the heart rate during the aerobic activity.

Strength and flexibility

The above aerobic exercise programs stress aerobic conditioning and are designed to be used to reach the weekly 10-point total required of the Border Patrol aerobic conditioning program. It's more difficult to quantify other types of workouts, such as strength training, because the individual exerciser may work with differing amounts of weights on differing schedules of sets and repetitions. Aerobic exercises can be quantified more accurately and offer the most protection against future cardiovascular disease.

Having said that, the Border Patrol encourages all its officers to do some strength and flexibility training with each workout session. The common strength-building exercises are sets of push-ups, pull-ups and sit-ups. Exercisers start by doing one or two sets of 5 to 10 repetitions in the morning and then several sets later in the day. They work up to 15 good push-ups per set; over time they very gradually work up to about 10 to 12 pull-ups several times per day.

Pull-ups are recommended for firefighters and law enforcement officers because they're similar to any pulling task that might be encountered on the job. Also, the pull-up is a very telling indicator of another aspect of physical fitness: If someone can't do a pull-up or a series of pull-ups, he or she is either too heavy or lacks basic upper-body strength. This also may indicate the individual may be unable to do the requisite upper-body work that the profession demands.

Sit-ups should be done as bent-knee sit-ups with the feet unsupported. This technique facilitates abdominal muscle development. With the feet unsupported, hip flexor muscles are not called into play in the exercise, which in turn puts less pressure on the low back — a source of irritation and weakness as someone ages.

Light flexibility exercises and some static stretching for the low back and lower limbs are also suggested as components of a strength and flexibility workout. And simply hanging from a pull-up bar prior to actually performing pull-ups can help stretch the shoulder girdle and the upper arms.

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Alfred F. Morris, Ph.D., is the director of health improvement and physical fitness for the U.S. Border Patrol. He is an adjunct professor at American University in Washington, D.C., and has degrees in exercise science, sports medicine, and health and physical education. Morris has written two texts and more than 200 scientific and educational articles on sports medicine, exercise physiology, diet and nutrition, and occupational health and physical fitness in the uniformed services.

CAD RISK INDEX

Risks	Levels of Risk	Points
Age	10-20	1
	21-30	2
	31-40	4
	41-50	6
	51-60	8
	Over 60	10
Heredity	No known history of heart disease	1
	1 relative over 60 with cardiovascular disease	2
	2 relatives over 60 with cardiovascular disease	4
	1 relative under 60 with cardiovascular disease	6
	2 relatives under 60 with cardiovascular disease	9
	3 relatives under 60 with cardiovascular disease	10
Weight	More than 5 pounds below standard weight	0
	5-pound deviation from standard weight	1
	6-20 pounds overweight	4
	21-35 pounds overweight	6
	36-50 pounds overweight	8
	51-65 pounds overweight	10
Smoking	Non-smoker	0
	Cigar and/or pipe	1
	10 cigarettes or less per day	4
	20 cigarettes per day	6
	30 cigarettes per day	8
	40 cigarettes per day or more	10
Exercise	Intensive occupational & recreational exertion	1
	Moderate occupational & recreational exertion	2
	Sedentary work & intense recreational exertion	4
	Sedentary occupational & moderate recreational exertion	6
	Sedentary work & light recreational exertion	8
	Complete lack of all exercise	10
Cholesterol & Dietary Fat	180mg or lower cholesterol; no animal or solid fats	1
	181-205mg cholesterol; 10% animal or solid fats	2
	206-230mg cholesterol; 20% animal or solid fats	5
	231-230mg cholesterol; 30% animal or solid fats	7
	256-280mg cholesterol; 40% animal or solid fats	8
	281-300mg cholesterol; 50% animal or solid fats	10
Blood Pressure	100 upper reading	1
	120 upper reading	2
	140 upper reading	5
	160 upper reading	7
	180 upper reading	9
	200 or higher upper reading	10
Gender	Female under 40	1
	Female 41 to 50	2
	Female over 50	3
	Male	5
	Stocky male	6
	Bald, stocky male	7
To use the Coronary Artery Disease Risk Index, add up the points that apply to you. Totals under 22 correlate to low risk; 23-26, mild risk; 27-32, moderate risk; 33 or higher, high risk.