Deployment and Altered Climates

Adapting to a

new environment, such as

extreme changes in climate

or altitude, imposes

considerable demands on

■

the body. This adaptation,

or acclimation, occurs

gradually, allowing the

individual to better tolerate and perform in that new

environment. Thus, acclimation is the gradual change

the body undergoes in order to function more efficiently

in a new environment.

Acclimating to New E n vir onments

Adapting to a new environment can take one to three weeks. During this time, endurance activities become more difficult and onset of fatigue occurs sooner. If environmental conditions permit, gradually increase the intensity of exercise until you reach your desired training intensity. Having a good aerobic fitness base will accelerate your acclimation to new environments. Factors that negatively affect acclimation include:

♦ Dehydration.

♦ Drinking alcohol.

♦ Cessation of physical activity.

♦ Electrolyte depletion.

♦ Inadequate energy intake.

♦ Illness.

♦ Infection.

♦ Injury.

♦ Loss of sleep.

General Nutrition Issues

Maintaining or improving health and fitness is more challenging in adverse conditions such as extreme heat, cold, or altitudes. Even highly, physically fit individuals can be quickly overcome by "environmental exposure" if proper preparation is overlooked or if symptoms of impending illness are ignored. The adaptation of the body to adverse environments increases energy expenditure and water losses. Furthermore, dehydration results in a loss of appetite. If energy and fluid needs are not met, then performance will be impaired. General suggestions for meeting increased energy and fluid requirements are provided below. Issues relevant to a particular environment are provided later.

Maintaining Energy Balance

♦ Eat a high-CHO diet to meet increased kcal needs,
as CHO are more readily absorbed and better
tolerated than fats or proteins.

♦ Avoid fatty foods which may not be well tolerated.

♦ Avoid high-protein intakes which will increase water loss and can
lead to dehydration. (See Chapter 2 page 9.)

♦ Eat small frequent meals.

♦ When eating field rations, eat the entrees as well as the other
food and beverage items provided in the pack.

♦ Drink a high-CHO beverage to increase your kcal intake if you
are having difficulty eating enough solid foods to meet your
energy needs.

Maintaining Fluid Balance q

Maintaining fluid balance is crucial to avoid dehydration, as stated ^^=' in Chapter 2 on page 17. Dehydration can limit performance and severe dehydration can be life-threatening. Tips for maintaining fluid balance include:

♦ Monitor hydration status by the frequency and color of your
urine. Infrequent and dark yellow urine suggests dehydration.

♦ When possible, monitor fluid status by weighing yourself prior to
and after prolonged physical activities. For every pound of weight
lost due to water losses, drink 2 cups (0.45 L or 16 oz.) of water.

♦ Thirst is not a good indicator of fluid status. Drink fluids
regularly throughout the day. When working in the heat, do not
drink more than 6 cups of fluid an hour.

♦ Avoid alcoholic beverages as alcohol increases fluid losses.

♦ Reduce caffeine consumption as caffeine increases fluid losses.

♦ Avoid salty foods as salt increases fluid needs.

♦ Drink CHO/electrolytes beverages during prolonged physical
activity or on extended missions (Chapter 11, page 90).