Cardiorespiratory Conditioning

The American College of Sports Medicine(ACSM) and the
Centers for Disease Control and Prevention recently formulated new guidelines for the
American public with respect to exercise. The new recommendations state that “Every US
adult should accumulate 30 minutes or more of moderate intensity physical activity on
most, preferably all, days of the week”. They defined moderate intensity physical activity
as “activity performed at an intensity of 3 to 6 METS, or the equivalent of brisk walking at
3 to 4 m.p.h. for most healthy adults”. Whereas the previous recommendations for the US
population emphasized the importance of extended periods of strenuous exercise, these
new guidelines state that short, intermittent bouts of moderate exercise are important and
sufficient for health benefits. The overall goal of these organizations is to promote
cardiorespiratory conditioning, an important aspect of overall fitness, health, and disease
prevention. However, activity above and beyond the recommendations for the public is
necessary for SEALs and other highly competitive athletes. In this chapter we will discuss:

• Basic concepts of cardiorespiratory conditioning.
•  How to estimate your maximal aerobic capacity.
• Types of aerobic activities and basic workouts.

Many of the definitions and terminology associated with cardiorespiratory
conditioning have been presented in Chapter 1. However, other terms are used
interchangeably to reflect cardiorespiratory conditioning; these include cardiovascular,
cardiopulmonary, and aerobic conditioning. The important point is that this form of
conditioning improves health and work capacity by enhancing the circulation and overall
functioning of the heart and lungs.

Conditioning and Deconditioning

Conditioning and deconditioning, also known as training and detraining, are

responsible for gains and losses, respectively, in fitness levels. Whereas conditioning is a

gradual process and may take six or more weeks to see specific effects, deconditioning

occurs relatively quickly. Some of the various metabolic and cardiorespiratory effects of

conditioning are presented in Table 1-4.

 

 

Effects of deconditioning will be noticed within one to four weeks. Deconditioning

reverses the positive metabolic, cardiac, respiratory and muscle enzyme effects that result

from conditioning. Some major effects of deconditioning include:

• Decrease in maximal aerobic capacity - Heart rate for a given exercise workload

              is higher and the amount of blood pumped by the heart with each beat is reduced.

• More rapid build up of lactic acid during exercise which leads to earlier fatigue.

• Reduction in levels of key muscle enzymes which regulate the muscle’s ability

              to generate energy from various sources.

• Reduced ability to store glycogen in muscle between workouts.

• Reduced breathing volume which will decrease the amount of oxygen being

            taken to the exercising muscle.

• Decreased endurance capacity - time to fatigue is shortened.

• Decreased ability to dissipate body heat during exercise: the ability to exercise

in adverse environments, such as in the heat, is reduced due to all factors

mentioned above.

Retraining is necessary to reverse the performance reducing effects of

deconditioning. However, deconditioning can be prevented or minimized by

maintaining usual exercise intensity during endurance and strength workouts, when

 

the number or length of work outs is decreased. Aerobic capacity and decreased lactic

acid accumulation during exercise can be maintained by training at least two to three times

per week at your usual training intensity. Strength gains can be maintained by including one

to two strength training workouts sessions per week. Specific training methods for

maintaining fitness under deployed conditions and while overcoming an injury will be

discussed in other chapters (see the next).

 

Active Recovery

This type of recovery means that you continue to exercise at a low to moderate

(30% to 50% of your maximal heart rate) intensity for several minutes after your regular

workout. For example, walk for 5 to 10 minutes after completing a run. The benefits of

active recovery and additional information about this type of recovery are provided in

the next: Cardiorespiratory Conditioning.