During the past several years we have learned a lot about the effects
of strength training and body composition. For example, a carefully controlled
study at Tufts University showed significant changes in body composition
from a basic program of strength exercise (Campbell et al. 1994).
The subjects added three pounds of lean weight, lost four pounds
of fat weight, increased their resting metabolic rate by seven percent and
increased their daily energy requirements by 15 percent after 12 weeks of
strength training.
Research with over 1100 previously sedentary adults revealed similar
body composition improvements from eight weeks of standard strength training
(Westcott and Guy 1996). The program participants increased their lean weight
by 2.4 pounds and decreased their fat weight by 4.6 pounds.
Of course, unfit individuals tend to improve their body composition
at faster rates than people who are presently doing strength exercise. Many
people want to know if strength training can further enhance body composition
in well-conditioned exercisers.
Previous studies have demonstrated that various high-intensity training
techniques are more effective than standard training protocols for increasing
muscle strength in both beginning and advanced participants (Westcott 1996,
1997a, 1997b; Westcott and La Rosa Loud 1997). As shown in Figures 1 and
2, slow training produced greater strength gains than standard training for
both beginning and advanced trainees. As illustrated in Figures 3 and 4,
breakdown training resulted in greater strength gains than standard training
for both beginning and advanced exercisers. Likewise, assisted training generated
greater strength gains than standard training for both beginning and advanced
subjects (see Figures 5 and 6).
We have recently examined the effects of combined high-intensity
training techniques on body composition changes in well-conditioned participants.
The six-week advanced exercise program included slow training, breakdown
training, assisted training, and pre-exhaustion training. The 48 subjects
added 2.5 pounds of lean weight and lost 3.3 pounds of fat weight as a result
of their training efforts, which represented more improvement than we expected
from regular strength exercisers.
We have been pleased with our participants' positive response to
the combined approach of high-intensity strength training techniques. Our
standard exercise protocol is outlined in Table I.
We observed that many program participants selected the pre-exhaustion
technique for their sixth week of high intensity training. Although we do
not have data that show this training method to be better than the others,
there may be some benefit in performing more pre-exhaustion sessions.
Psychologically, changing exercises at the point of muscle fatigue may be
more appealing than performing more repetitions of the same movement pattern
with less weight or with manual resistance. Physiologically, performing two
different exercises for the target muscle group recruits more muscle fibers
which may enhance the training stimulus. In addition to more exercises,
pre-exhaustion programs require more training time and may therefore be the
best high-intensity technique for burning calories.
Table I: Standard Exercise Protocol
| Week Days |
| Total Exercises |
|
| 1. M & F | Breakdown br> (10 reps to fatigue br> plus 3 reps with br> 10-20% less weight) |
|
|
| 2. M & F | Assisted br> (10 reps to fatigue br> plus 3 reps with br> manual assistance) |
|
|
| 3. M & F | Slow Positive br> (5 reps to fatigue br> with 10 seconds lifting br> and 4 seconds lowering) |
|
|
| 4. M & F | Slow Negative br> (5 reps to fatigue br> with 4 seconds lifting br> and 10 seconds lowering) |
|
|
| 5. M & F | Pre-Exhaustion br> (10 reps to fatigue with br> first exercise plus 5 reps br> with second exercise) |
|
|
| 6. M & F | Personal Preference br> (Trainee chooses the br> technique that seemed br> most productive) |
|
|
As many of our intermediate level strength trainees want to improve
their body composition, we presently provide high-intensity training programs
with more emphasis on pre-exhaustion techniques (Table II). The results are
encouraging, but we try to be cautious about overtraining. Our members seem
to respond well to six weeks of high-intensity training followed by six weeks
of standard training to maintain their new level of strength and
fitness.
Although we have not previously provided nutritional counseling to
our high-intensity training participants, this would undoubtedly be beneficial
for clients who want to lose fat as well as build muscle. A combination of
individualized high-intensity strength exercise and sound dietary guidelines
should produce significant improvements in body composition.
Table II: High Intensity Training Techniques
| |||
|
|
|
|
| Breakdown Training | Perform about 10 reps br> to fatigue with standard br> weightload. Immediately br> reduce resistance 10-20% br> and perform about 3 br> more reps to second br> level of fatigue. | Complete 10 leg br> extensions with 150 br> lbs., then 3 more reps br> with 120 lbs. | Change resistance br> as quickly as possible br> to maximize the br> training effect. |
| Assisted Training | Perform about 10 reps br> to fatigue with standard br> weightload. Trainer br> assists with 3 post br> fatigue reps on lifting br> phase only. | Complete 10 leg br> extensions with 150 br> lbs., then 3 more reps br> - with manual assistance br> from trainer. | Assistance is given br> only on the positive br> muscle action where br> it is necessary, but not br> on the stronger nega- br> tive muscle action br> when it's unnecessary. |
| Slow Positive Training | Perform about 5 reps br> to fatigue with 10% less br> than standard weight-load, br> taking 10 seconds for each br> positive muscle action and br> 4 seconds for each negative br> muscle action. | Complete 5 leg br> extensions with br> 135 lbs., counting br> 10 secs up and 4 secs br> down for each rep. | Be sure to breathe br> continuously br> throughout br> every repetition. |
| Slow Negative Training | Perform about 5 reps br> to fatigue with 5% less br> than standard weightload, br> taking 4 seconds for each br> positive muscle action br> 10 seconds for each br> negative muscle action. | Complete 5 leg br> extensions with br> 142.5 lbs., counting br> 4 secs up and 10 secs br> and down for each rep. | Use smooth and br> continuous move- br> ments, rather than br> choppy stop and br> go movements. |
| Pre-Exhaustion Training | Perform two successive br> exercises for target muscle br> groups, typically a rotary br> exercise followed immed- br> iately by a linear exercise. br> Use 10 reps to fatigue in br> the first exercise and 5 reps br> to fatigue in the second. | Complete 10 leg br> extensions with br> 150 lbs., then 5 leg br> presses with 300 lbs. | Take as little time br> as possible between br> the two successive br> exercises to maximize br> the |
Table III: Examples of Pre-Exhaustion Exercise Combinations
1. Leg extension followed by leg press. br>
2. Leg curl followed by leg press. br>
3. Dumbbell lunge followed by barbell squat. br>
4. Dumbbell fly followed by barbell bench press. br>
5. Dumbbell pullover followed by lat pulldown. br>
6. Dumbbell lateral raise followed by dumbbell press. br>
7. Dumbbell curl followed by chin up. br>
8. Dumbbell overhead extension followed by bar dip.
Wayne L. Westcott, Ph.D., is fitness research director at the South
Shore YMCA in Quincy, MA. Dr. Westcott has written the Muscular Strength
And Endurance chapter for the ACE Personal Trainer Manual and has authored
several textbooks on strength training.
References
Campbell, W., M. Crim, V. Young & W. Evans. (1994). Increased
energy requirements and changes in body composition with resistance training
in older adults. American Journal of Clinical Nutrition, 60:
167-175.
Westcott, W. (1996). Strength training for life: Make your method
count. Nautilus Magazine, Spring 5: 2, 3-5.
Westcott, W. and Guy, J. (1996) A physical evolution: Sedentary adults
see marked improvements in as little as two days a week. IDEA Today 14:
9, 58-65.
Westcott, W. (1997a). Research: Research on advanced strength training.
American Fitness Quarterly, 15: 4, 15-18.
Westcott, W. (1997b). Strength training 201. Fitness Management,
13:7, 33-35.
Westcott, W. and La Rosa Loud, R. (1997). A better way to beef up
strength workouts. Perspective, 23: 5, 32-34.