The Navy SEAL Physical Fitness Guide 81
Target heart rate during warm-up should be
about 60% of maximal.
During your warm-up, work on efficient stroke “stealth” swimming! Warming-up
is an appropriate time to include stroke drills. This serves the purpose of providing stroke
patterning along with the warm-up.
Basic Principles of Interval Training
SEALs need to concentrate on swim training that will enhance endurance: interval
swim training will allow this to happen. Interval training sets (for both strength and
endurance) are generally comprised of repeated swims lasting 45 seconds to 4 minutes.
Basics of interval training include the following:
" Swim at a slow to moderate pace for five to ten minutes to warm-up muscles
and cardiorespiratory system." For anaerobic training, sets should be performed until repeat times can no
longer be held. There is no magical number of repetitions for a set, but the
distance is typically 50 to 100 meters, or a time of about 45 seconds." Swimming at a prescribed intensity pace for as long as possible is most
important. When desired pace can no longer be sustained, the set should be
terminated." Work:recovery ratios play an important part in the type of adaptation that
occurs. A 1:1 work:recovery ratio would be to swim 45 seconds and rest 45
seconds, whereas a 1:2 ratio would be to swim 45 seconds and rest 90 sec-
onds." To stimulate endurance adaptations, recovery intervals between repetitions
should be less than 30 seconds. For maximum benefit, it is best to keep the
interval less than 15 seconds." For anaerobic adaptations to occur, recovery intervals should be in excess of
one minute and up to at least twice the duration of the repetition swim. These
effects occur independent of the repetition distance or pace." The longer the rest interval, irrespective of the distance being repeated, the
greater the use of the anaerobic system. With long rests, it takes considerably
longer for the aerobic energy system to be reactivated. Short rest intervals
keep the aerobic system functioning, particularly during initial recovery.Interval training is the backbone
of a swimming workout.