HIGH-INTENSITY TRAINING
In the area of strength training, there are as many workout routines as there
are body builders, weight lifters, power athletes, and strength coaches. Every
strength expert seems to possess the perfect training program for maximizing
muscle development.
Fortunately, several respected professional associations have come to consensus
on recommended training procedures for safe, sensible, and successful strength
exercise. These include the American College of Sports Medicine, the American
Council on Exercise, and the YMCA of the USA. The training guidelines, which
include the following, are designed for average adults who desire a higher level
of strength fitness.
1. Training Exercises: Eight to twelve strength exercises that address all of
the major muscle groups.
2. Training Frequency: Two to three nonconsecutive training sessions per week.
3. Training Sets: One or more sets of each exercise.
4. Training Resistance: Approximately 70 to 80 percent of maximum resistance.
5. Training Repetitions: Approximately eight to twelve controlled repetitions.
6. Training Progression: Approximately 5 percent increase resistance whenever 12
controlled repetitions are completed.
7. Training Speed: Slow to moderate movement speed--for example, two seconds
lifting and four seconds lowering.
8. Training Range: Whenever possible, full range of joint movement.
These basic exercise procedures have proven to be an effective and efficient
means for developing muscle strength and mass. Studies with youth, adults, and
seniors have shown significant increases in muscle strength (about 70 percent)
and muscle mass (about 3 pounds) after eight weeks of training in the
recommended manner. While these improvements continue for several months,
progress comes more slowly and eventually begins to plateau.
Strength Plateaus
Strength plateaus are an inevitable part of the muscle-building process. At some
point, the training effort that previously stimulated positive muscle
adaptations is no longer productive. This does not mean that further strength
development is impossible, but it does indicate a need for program changes.
Most people recognize that, to overcome a strength plateau, they must train a
little harder. However, many exercisers confuse working harder with working
longer. That is, they increase their exercise duration rather than their
exercise intensity. For example, instead of performing one set of each exercise,
they jump to two or three sets of each exercise. While this certainly increases
the work volume, it has little impact on the work intensity.
Let's say that John typically performs 10 leg extensions with 150 pounds, which
is 75 percent of his maximum resistance. As John's quadriceps muscles fatigue,
his momentary strength decreases on a repetition-by-repetition basis. By his
10th repetition John has reduced his starting strength by 25 percent, and he can
no longer lift 150 pounds. That is, when John's quadriceps muscles fatigue below
75 percent of maximum strength, he can no longer lift 75 percent of maximum
resistance.
If John chooses to perform a second set of leg extensions, he will clearly
perform a greater work volume. He is unlikely to achieve a greater work
intensity, however, by completing additional sets of leg extensions. This is due
to the fact that each set of 150-pound leg extensions fatigues the same 25
percent of John's quadriceps muscle fibers. Because the same muscle fibers are
activated in the same recruitment pattern, there is little response difference
between the first and last set of a given exercise.
High-Intensity Strength Training
The primary intent of high-intensity strength training is to fatigue additional
muscle fibers during a more demanding exercise set. One means of achieving this
objective is to reduce the exercise resistance at the point of muscle failure.
For example, when John can complete no more leg extensions with 150 pounds, he
may immediately reduce the resistance to 130 pounds and perform a few more
repetitions. By so doing, he may fatigue more muscle fibers and provide a
greater strength-building stimulus. With this technique, called breakdown
training, John experiences two levels of muscle failure and fatigues 35 percent
of his quadriceps muscle fibers.
Research on Breakdown Training
In a recent research study, we compared standard training with breakdown
training. Forty-five adults (men and women between 25 and 54 years of age) and
15 seniors (men and women between 55 and 84 years of age) participated in this
study.
During the first four weeks all 60 subjects trained in the standard manner (one
set of 8-12 repetitions per exercise). During the second four weeks half of the
subjects continued to perform one set of 8-12 repetitions per exercise. The
other half performed one set of 8-12 repetitions, then immediately reduced the
weightload by 10 pounds and completed as many additional repetitions as possible
(typically 2-4 breakdown reps with the lighter resistance).
The subjects who performed breakdown training experienced significantly greater
strength gains than the subjects who trained in the standard manner. The
high-intensity-trained adults gained 39 percent more strength and the
high-intensity-trained seniors gained 100 percent more strength.
Given these findings, it would appear that breakdown training is more effective
than standard training for developing muscle strength. It is assumed that the
breakdown repetitions produced a greater strength-building stimulus. It is also
likely, however, that the breakdown repetitions encouraged greater training
effort. That is, the subjects who performed breakdown repetitions probably
pushed themselves harder after realizing that the standard training set did not
fully fatigue their muscles. This learning effect may explain the large
difference in strength development between the two senior groups.
Assisted Training
Another means of increasing the training intensity is assisted training. Like
breakdown training, the resistance is reduced at the completion of a standard
exercise set to enable a few additional repetitions. Instead of changing the
weightload, however, a trainer gives just enough manual assistance to complete
another repetition.
Because we can lower more resistance (negative muscle contraction) than we can
lift (positive muscle contraction), the assistance is limited to the lifting
movements. The trainee handles the full resistance on the lowering movements.
Pre-Exhaustion Training
Pre-exhaustion training is also designed to fatigue more muscle fibers than
standard training. With this high-intensity technique, you complete two
successive exercise sets for the same muscle group. The first set is typically
performed with a rotary exercise that fatigues the target muscle group. The
second set is conducted with a linear exercise that involves both the fatigued
target muscle group and a fresh muscle group.
For example, you may do a set of chest flies to pre-exhaust the pectoralis major
muscles. At the point of failure, you may immediately perform a set of chest
presses using both the fatigued pectoralis major muscles and the fresh triceps
muscles.
By incorporating different movement patterns and fresh muscles, pre-exhaustion
training produces greater fatigue in the target muscle group. Other effective
pre-exhaustion combinations include lateral raises followed by overhead presses
for the deltoid muscles, pullovers followed by pulldowns for the latissimus
dorsi muscles, arm curls followed by chin-ups for the biceps muscles, arm
extensions followed by dips for the triceps muscles, and leg extensions followed
by leg presses for the quadriceps muscles.
Conclusion
Our study with adults and seniors demonstrated significantly more strength
development with breakdown training than with standard training. Although not
researched, experience indicates that assisted training and pre-exhaustion
training are also effective means of producing more muscle fiber involvement and
promoting greater strength gains. In addition to the physiological adaptations
associated with high-intensity strength exercise, there would appear to be
psychological changes as well. That is, people who practice high-intensity
techniques are likely to train harder than those who have not exercised in this
manner.
Because of the greater effort required by high-intensity strength exercise, it
should not be overdone. A single breakdown set, a few assisted repetitions, and
an occasional pre-exhaustion workout will be sufficient. Most important, be sure
to perform every repetition in standard and high-intensity exercise with proper
technique and controlled movement speed