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Old 05-10-2006, 06:53 AM
EricT EricT is offline
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A BRIEF ON BELTS
A B E LT MAY NOT BE AS “ S U P P O R T I V E ” A S Y O U T H I N K
By James Krieger

BELT PRIMER
Before we talk about belts, injury risk, and performance, we need to delve into how a belt supposed to work. During heavy lifting, the transverse abdominus, a hooplike muscle that surrounds your waist and lies deep in your abdomen, “squeezes” your torso. This increases the pressure in your stomach, which is known as intra-abdominal pressure IAP). This action provides support to your trunk by essentially making your torso stiffer, adding strength and support to your spine, and can even prevent your spine from buckling with a heavy load on your back.10 Now, wearing a belt creates even more IAP,4, 7, 8, 11 which, theoretically, would provide even more support to your spine.

NO BELTS ALLOWED
Though I dug deep, I couldn’t find any studies that directly examined if belts can decrease injury risk in athletes. However, that doesn’t mean we can’t put our brains to use and derive some logical conclusions. If a weight belt truly adds extra spinal support, then it makes sense that the erectors, the primary muscles involved in extending your back and keeping you upright, would be relieved of some of their duty. Since a muscle’s degree of work can be measured via electrical activity, it would also follow that such activity would decrease with the use of a belt, since the muscles wouldn’t need to work as hard.

However, in five out of six studies that looked at the electrical activity of the erectors with belt use, there was no decrease in erector activity.1, 7, 8, 11-13 And the lone study that did show a decrease has been criticized for its statistical analysis.3 So the next deduction is that a belt doesn’t add extra spinal support and that therefore the concept of injury prevention may be flawed.

Actually, if you dig deep enough, you would learn that a belt might actually cause problems, rather than prevent them. You see, your spine comprises 24 little joints that are constructed to allow for a certain range of motion. By wearing a belt, you might immobilize certain portions of your back when they’re supposed to be moving, thereby increasing stress to other parts of the spine and making those parts more vulnerable.5

Wearing a belt can also increase blood pressure and cardiovascular strain.6 Finally, although there’s no decrease in surface abdominal muscle activity when a belt is used,11, 12 it’s possible that a belt might decrease the activity of the deep abdominal muscles. This is because the belt may relieve some of the need of the deep abdominals to supply IAP.

This, in turn, would reduce the training stimulus to these muscles. Eric Burkhardt, MA, CSCS, the strength and conditioning coach for the University of California, Irvine, agrees. “I have not worn a belt during any exercise for about 15 years of relatively heavy training,” says Burkhardt. “In doing so, I feel that I have developed my abdominals’ ability to create sufficient IAP, eliminating the need for a belt. I’m quite certain that had I used a belt on a regular basis, my trunk musculature wouldn’t be as strong as it is today.”

A BELT, PLEASE
The value of using a belt is clearly in question, at this point. But let’s shift gears and take a look at a study that favors the belt.2 Eight males performed six weight-training xercises for 3 sets of 10: a deadlift, high pull, squat, clean, bent-over row, and bicep curl. Four subjects wore a belt, while four didn’t. After the training session, the subjects who wore a belt reported less discomfort while lifting.

Their height decreased by an average of 2.87 mm, while for the subjects who didn’t wear a belt height decreased by 3.59 mm. This indicates less “spinal shrinkage” in the subjects who wore a belt, implying that the spine experienced less compression. This might be important to injury prevention. Why? In yourspine there are soft disks made out of cartilage, called intervertebral disks, which act as cushions. More compression on your spine means more compression on these disks. Relieving some of the compression might be beneficial, since these disks can be relatively easily injured.

While this looks like evidence in favor of the belt, you need to be cautious in interpreting the results. The difference in spinal shrinkage between the groups was not statistically significant, meaning it might have been due to random chance. Also, the subjects were experienced weightlifters who may have been accustomed to wearing a belt. This might explain why they felt discomfort when they didn’t wear one.

With all this talk of injury prevention, we still haven’t addressed the effect of a belt on performance. Probably the one type of athlete that would derive the greatest performance boost from a belt is the powerlifter. Most powerlifters that we talked to agreed that they could add at least 30 pounds to their squat and deadlift by wearing a belt. Also, two studies found that the subjects could squat faster with a belt,7, 13 indicating that they’re generating more power. This in and of itself could contribute to why powerlifters feel that they can lift more with a belt, though you can’t dismiss the fact that feeling more secure with a belt also has a positive effect.7

SOMETIMES

So after yanking you back and forth, how can we make sense of the data? Here are some major pointers to bear in mind:

Constant reliance on a belt for every lift, even max attempts, probably isn’t a good idea and could result in belt dependence. While there’s no solid evidence for belt use, there’s also no indication that occasional use is harmful. If you decide to use a belt, make sure you get a fair amount of beltless training also. Limit your belt use to some of your maxes and definitely consider using one in competition for some added power.If you’ve been consistently wearing a belt in training, it’s probably time to get your body accustomed to lifting without one. Start at around 60% of your max and slowly progress by 2 to 5% per week or as tolerated.

Proper lifting technique and appropriate progression are probably much more important to injury prevention than wearing a belt. “The athletes I train aren’t using lifting belts and never have,” says Burkhardt. “I haven’t had any serious back injuries in my weight room and strongly feel that this is due to being a stickler about proper technique.” Maintaining neutral spine is an important part of proper technique. Neutral spine means keeping the natural curvature of your back when you lift. Don’t round it, and don’t hyperextend it either. This keeps the pressure on those intervertebral disks even on all sides, reducing the risk of injury.

Belt or no belt, a brief Valsalva maneuver (holding your breath) may help protect your back. This increases IAP and tends to reduce erector activity, suggesting a reduced spinal load.11 However, avoid excessive breath holding because it can result in a dramatic ncrease in blood pressure and, if prolonged, could cause blackouts.9 The best way to avoid these problems is to start breathing out once you’ve passed the sticking region of a lift.

REFERENCES
1. Bauer, J.A., A. Fry, and C. Carter. The use of lumbar-supporting weight belts while
performing squats: Erector spinae electromyographic activity. Journal of Strength and
Conditioning Research 13:384-388, 1999.
2. Bourne, N.D., and T. Reilly. Effect of a weightlifting belt on spinal shrinkage. British Journal
of Sports Medicine 25:209-212, 1991.
3. Group, National Institute for Occupational Safety and Health Back Belt Working. Workplace
Use of Back Belts: Review and Recommendations. Cincinnati: National Institute for
Occupational Safety and Health, 1994.
4. Harman, E.A., R.M. Rosenstein, P.N. Frykman, and G.A. Nigro. Effects of a belt on intraabdominal
pressure during weight lifting. Medicine and Science in Sports and Exercise
21:186-190, 1989.
5. Howard, R.L. Back pain, intra-abdominal pressure, and belt use. Strength and Conditioning
Journal 21:42-43, 1999.
6. Hunter, G.R., J. McGuirk, N. Mitrano, P. Pearman, B. Thomas, and R. Arrington. The effects
of a weight training belt on blood pressure during exercise. Journal of Applied Sport
Science Research 3:13-18, 1989.
7. Lander, J.E., J.R. Hundley, and R.L. Simonton. The effectiveness of weight-belts during
multiple repetitions of the squat exercise. Medicine and Science in Sports and Exercise
24:603-609, 1992.
8. Lander, J.E., R.L. Simonton, and J.K.F. Giacobbe. The effectiveness of weight-belts during
the squat exercise. Medicine and Science in Sports and Exercise 22:117-126, 1990.
9. MacDougall, J.D., D. Tuxen, D.G. Sale, J.R. Moroz, and J.R. Sutton. Arterial blood pressure
response to heavy resistance exercise. Journal of Applied Physiology 58:785-790, 1985.
10. McGill, S.M., and R.W. Norman. Low back biomechanics in industry: The prevention of
injury through safer lifting. In: Current Issues in Biomechanics. M. Grabiner (Ed.).
Champaign, IL: Human Kinetics, 1992, pp. 69-120.
11. McGill, S.M., R.W. Norman, and M.T. Sharratt. The effect of an abdominal belt on trunk
muscle activity and intra-abdominal pressure during squat lifts. Ergonomics 33:147-160,
1990.
12. Miyamoto, K., N. Iinuma, M. Maeda, E. Wada, and K. Shimizu. Effects of abdominal belts
on intra-abdominal pressure, intra-muscular pressure in the erector spinae muscles and
myoelectrical activities of trunk muscles. Clinical Biomechanics 14:79-87, 1999.
13. Zink, A.J., W.C. Whiting, W.J. Vincent, and A.J. Mclaine. The effects of a weight belt on
trunk and leg muscle activity and joint kinematics during the squat exercise. Journal of
Strength and Conditioning Research 15:235-240, 2001.
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If you act sanctimonious I will just list out your logical fallacies until you get pissed off and spew blasphemous remarks.
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