Field Notes

Immune Friendly Nutrients

In addition to adequate energy, a number of nutrients have been found to enhance the function of the human immune system. They include:

Vitamin C-(citrus fruits, broccoli, peppers) enhances immune response.

Vitamin E-(whole grains, wheat germ, vegetable oil) stimulates immune response.

Beta Carotene-(carrots, sweet potatoes) stimulates natural killer cells.

Vitamin B6-(potatoes, nuts, spinach) promotes white-cell proliferation.

Folate-(peas, salmon, romaine lettuce) increases white-cell activity.

Selenium-(tuna, eggs, whole grains) promotes antibacterial action.

Zinc-(eggs, whole grains, oysters) promotes wound healing.

Several of these nutrients (Vitamins C, E, and B-carotene) also serve as antioxidants. (From B. Sharkey, Fitness and Work Capacity, NFES 1596, 1997).

Note: For a comprehensive list of nutrients that influence the immune system see the complete text of Dr. Steve Woods' article in the MTDC publication Wildland Firefighter Health and Safety: Recommendations of the April 1999 Conference.

Pack Test

The pack test is used to determine a candidate's ability to carry out the arduous duties of a wildland firefighter. The test, which replicates part of the firefighters' job, requires the same energy expenditure firefighting tasks (7.5 kcal/min).

The pack test has been taken by thousands of individuals in Federal and State agencies in the United States, Canada, and Australia. Even though more than 90 percent of the candidates pass the test, it has been criticized as too difficult, the pack (45 lb) as too heavy, and the pace (4 mph) as too fast. Smokejumpers carry 110 lb for 3 miles to qualify for duty. Female Army recruits have been trained to carry 75 lb at 4.4 mph. Marines routinely carry 75 lb in awkward Alice packs, even on snowshoes. A recent article in the journal Military Medicine recommends a backpack run test, a 2-mile run with a 66-lb pack, as "a model for a fair and occupationally relevant military fitness test." According to the authors, the backpack run test uses standard-issue equipment, eliminates body size bias, and measures work- and health-related components of fitness.

Wildland firefighters are told not to run while taking the pack test. The pack test is a pass/fail test. Running is not necessary to pass: doing so increases the risk of injury.

Candidates for the pack test should be reminded of proper lifting techniques and the need to warm up and stretch before beginning the test. Candidates should follow all safety instructions, wear a comfortable pack, hike with an upright posture, and avoid extreme body positions (such as crouching or leaning). Finally, candidates should be told they are free to stop at any time for any reason. Candidates should train before taking the test.

Fitness for Firefighting

Like athletes, serious firefighters realize that physical activity and training are a year-round commitment. Job-specific training and work hardening should begin weeks before taking the pack test. Before training, candidates should complete the PAR Q or an equivalent health-screening questionnaire. They should consult a physician if they are over 45 years of age or if the questionnaire indicates that they should do so.

Begin specific training for the pack test at least 6 to 8 weeks before taking the test and reporting for duty. Train by hiking or power walking using the ankle-height footwear that will be worn during the test. Pack test candidates should:

• Hike a 3-mile flat course without a pack. When they can cover the course in less than 45 minutes, they should carry a 25-lb pack on training hikes.
• Increase the pack weight until they can hike 3 miles in 45 minutes with a 45-lb pack.

Candidates can also:

• Hike hills (with a pack) to build leg strength and endurance.
• Jog the flat course (without a pack) to build aerobic fitness.
• Cross-train (mountain bike, lift weights) to build stamina and strength.

(For more information about training, see B. Sharkey, Fitness and Work Capacity, NFES 1596, 1997.)

Technical Committee Meets

Members of the Wildland Firefighter Health and Safety Technical Committee met in Indianapolis during the June annual meeting of the American College of Sports Medicine. They discussed current research, recommended research priorities, and planned field studies. In addition, the committee will meet by teleconference and may hold a fall meeting to plan Fiscal Year 2001 field studies.