The “spot
reduction” hypothesis states that exercise concentrated on a specific area will
result in preferential reduction of the fat deposits in that specific area. For
example, abdominal exercises are
often promoted as an effective means to reduce abdominal fat and trim the
waistline.
However results in
scientific literature are mixed, especially old studies. Spot reduction is generally not considered
valid without creating a consistent energy deficit, and even in a caloric
deficit it is no guarantee you will burn fat at the exercised region.
In 1956 "spot" reducing was deemed possible (1) but it was only in
1960 that this question was addressed scientifically.
1960
In 1960 an experiment set out to test the hypothesis of spot reduction.
They investigated the relative value of generalized versus localized exercise
in the reduction of weight and in
changes in segmental volume. A control group was also used with no systematic
exercise and no diet regime.
A diet of from 2,000 to 2,200 calories with an average of 2,070 calories
was arbitrarily chosen as a
reasonable approximation of probable
energy needs. The diet was followed for six
weeks by the two experimental groups. Each meal was served in a special
dining room of the University Student Union. At the end of each week, each
subject signed a card indicating whether or not they ate all of the food served
and no food or liquid of caloric value other than that in the specified diet. Subjects
in the experimental groups lost some weight (around -2kg).
They measured weight, and determined volume of several segments of the boy using water displacement
method. The analysis of segment volumes for the two experimental groups
indicated no noticeable differential
effect attributable to spot exercise (2).
1962
In an old study back in 1962, researchers compared the
effect of two types of exercises, spot (hip and abdominal areas) and generalized (upper back, shoulder girdle, and the
extremities), on the physical contour of the overweight individual.
The experiment included a uniform diet
leading to a slight reduction in body weight. Since the diet was the same for all subjects (2,000 to 2,200 calories)
energy balance varied considerably within the group. Weigh reduction was achieved via a small deficit in the daily calorie intake an exercise energy cost, specifically
44 % of the mean predicted weight
loss was attributed to the energy cost of the very severe exercise program.
They measured the differences between pre- and
postexercise diameters of waist and
thigh and the area measurement of thigh and leg. Results indicated evidence of
reduction in body segments where fat accumulations had been most conspicuous,
regardless of the type of exercise administered (3).
1965
In 1965 subjects were put under a regime of six isometric abdominal contractions held
for 6 sec. each. The exercises were done daily for a period of four weeks, with no additional
abdominal or conditioning exercises, and no
appreciable change in weight. In order to rule out any possible influence of weight
gain or loss on girth and skinfold thickness, any subject whose final weight
deviated more than 3 percent from her initial weight was eliminated from the
study.
Significant reductions were obtained in girth and subcutaneous fat at the waistline
and the umbilical level of the abdomen (4). Authors claimed it could be considered a form of
"spot-reducing," however and these data differ from previous findings
(2,3).
1978
For this one 27 women were assigned to the localized
exercise regimen and performed calisthenic-type activities concentrated on the abdomen, hips, and thighs while the generalized exercise group (n =
29) participated in a variety of typical aerobic activities for 10 weeks.
Exercise sessions for both groups were conducted 3 days per week for 30
minutes.
A total of 12 skinfold,
girth, densitometric, and derived variables were assessed before and after
the experimental period. There was not a significant difference between groups.
The results indicate that although either
general aerobic or localized exercises are effective in altering the
anthropometric and densitometric characteristics of females, neither exercise
regimen was shown to be more effective (5).
1984
This study evaluated
the effects of a 27-day sit up exercise training program on adipose cell size
and adiposity. Fat biopsies were taken from the abdomen, subscapular, and
gluteal sites. Subjects were engaged in a progressive training regimen five
days/week. The total number of sit ups done was 5004.
Body weight, total body fat (underwater weighing), and fatfolds and
girths remained unaltered. But cell diameter decreased significantly. There
was no difference in the rate
of change in cell diameter among the three sites suggesting there was no
preferential influence of a possible lipolytic mobilizing factor or of enhanced
adrenergic responsiveness. Because cell diameter decreased significantly at the
three sites, authors suggested that the
sit up regimen had a more general than specific effect on the overall size
(diameter and volume) of the adipose cells.
They also
suggested that if only fatfold and girth measures are taken,
it is possible to mask cellular changes in adiposity when there are no
accompanying changes in gross body composition. Furthermore, to reduce the fat content at a given body
site, total body composition must be altered; a relatively selective exercise regimen of sit ups does
not solely affect the specific fat accumulation in the abdominal area, and does not preferentially
reduce adipose cell size or subcutaneous fat thickness in the abdominal region
to a greater extent compared to other adipose sites (6).
2007
The hypothesis of
spot reduction was reexamined this time for the arms. Subjects participated in 12 wk of supervised resistance training
of their nondominant arm. Magnetic
resonance imaging and skinfold calipers examined subcutaneous fat in the
nondominant (trained) and dominant (untrained) arms before and after resistance
training. While measurements by skinfold showed a decrease in subcutaneous fat
in the trained arm indicating spot reduction, MRI measurements showed no
significant differences in the total sample size and by gender indicating spot
reduction did not occur as a result of resistance training (7).
Authors indicated
that MRI, sensitive to changes along
the entire upper arm, detected greater variation
in resistance training responses, preventing significant differences between
trained and untrained arms, and that variation in upper-arm resistance training
response was not evident from a single skinfold measurement at the belly of the
muscle.
2011
A more recent (pilot) study investigated the
effect of abdominal exercises on abdominal fat in 24 participants. A control
group received no intervention and the abdominal exercise group performed 7
abdominal exercises, for 2 sets of 10 repetitions, on 5 d/wk for with an average
of 75 minutes of abdominal
exercise per week for 6 weeks. All participants maintained an isocaloric diet throughout the study.
There was no significant effect of abdominal
exercises on body weight, body fat percentage, android fat percentage, android
fat, abdominal circumference, abdominal skinfold and suprailiac skinfold
measurements. They concluded that six
weeks of abdominal exercise training alone was not sufficient to reduce
abdominal subcutaneous fat and other measures of body composition (8).
2013
Another more recent study examined
the effects of a localized muscle
endurance resistance training program on total body and regional tissue
composition. They trained their nondominant leg during 12 weeks, 3 sessions per week. Each session consisted of 1 set of
960-1,200 repetitions (leg press
exercise), at 10-30% 1 repetition maximum. Energy intakes were registered
using a food recall questionnaire.
Using DEXA, it was determined that
no significant changes in bone mass, lean mass, fat mass, or fat percentage
were observed in both the control and trained leg. A significant decrease in fat mass was observed in the
upper extremities and trunk (10.2 and 6.9%, respectively). The reduction of fat mass in the upper
extremities and trunk was significantly greater than the fat mass change observed in the trained leg but not in the
control leg.
Therefore, the training program was effective in
reducing fat mass, but this reduction was not achieved in the trained body
segment (9).
Discussion
Most of the studies
(2,3,4,5) on the effects of selective site exercise training have relied on gross measures of tissue
change (fatfolds, girths, and volume) as
opposed to cellular methods (6). Even MRI compared with skinfolds can give
different results with skinfolds suggesting spot reduction and MRI refuting it (7). DEXA can also give a more precise assessments than gross measures of tissue change and
show there is no preferential spot reduction (9).
The limitations of the skinfold technique
are well known, and the results tend to vary
according to age, sex, distribution of fat, and measurement technique (7,10).
Skinfold-thickness equations frequently used by
clinicians and practitioners underestimate %BF (11).
Skinfold thickness (SFT) and bioelectrical impedance
(BIA) are better suited for nonobese subjects due to an obvious lack of agreement between the DEXA-BIA and DEXA-SFT methods in
obese patients (12). In addition, FM can be underestimated by BIA and SFT
as compared to DEXA and better precision is obtained by DEXA method among the
others. DEXA should be considered as the
method of choice in obese patient monitoring, since reproducibility gains special importance, other than the accuracy
in the context (12).
However even such gross
measures can suggest spot reduction does not happen (2,3,5), like in and old
study (1971) comparing the fat deposition patterns in the active and nonactive
forearms of male and female tennis players with those of a group of
controls, failing to support the
spot-reduction hypothesis (13).
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References
1. Brobeck, J. R., Ancel Keys, and Jean Mayer 1956. Is spot reducing
possible? Vogue, May 15, 44.
2. CARNS, MARIE
L. Segmental volume reduction by
localized versus generalized exercise. Human Biol. 32: 336-76, 1960.
3. Schade, M,
Helledrandt, FA, Waterland, JC, and Carns, M. Spot reducing in overweight
college women: Its influence on fat distribution as determined by photography. Res Q 33: 461–471, 1962
4. Mohr, D. Changes in
waistline and abdominal girth and subcutaneous fat following isometric
exercise. Res Q 36: 168–173, 1965.
5. Noland, M and
Kearney, J. Anthropometric and densitometric responses of women to specific and
general exercise. Res
Q 49: 322–328, 1978.
6. Katch, FI, Clarkson,
PM, Kroll, W, and McBride, T. Effects of sit up exercise training on adipose
cell size and adiposity. Res Q 55: 242–247, 1984.
7. Kostek, MA,
Pescatello, LS, Seip, RL, Angelopoulos, TJ, Clarkson, PM, Gordan, PM, Moyna, NM,
Visch, PS, Zoeller, RF, Thompson, PD, Hoffman, EP, and Price, TB. Subcutaneous
fat alterations resulting from an upper body resistance training program. Med Sci Sports Exerc 39: 1177–1185, 2007.
8. Vispute SS, Smith JD, LeCheminant JD, Hurley KS. The
effect of abdominal exercise on abdominal fat. J Strength Cond Res. 2011 Sep;25(9):2559-64.
9. Ramírez-Campillo
R, Andrade DC, Campos-Jara C, Henríquez-Olguín C, Alvarez-Lepín C, Izquierdo M.
Regional fat changes induced by localized muscle endurance resistance training. J Strength Cond Res.
2013 Aug;27(8):2219-24.
10. Lohman, TG.
Skinfolds and body density and their relation to body fatness: A review. Hum Biol 53: 181–225, 1981.
11. Matthew J
Peterson, Stefan A
Czerwinski, Roger M Siervogel. Development and
validation of skinfold-thickness prediction equations with a 4-compartment model. Am J Clin Nutr May 2003. vol. 77 no. 5 1186-1191
12. Taner Erselcana Ferhan Candanb Sabriye Saruhanc Tulay Ayca. Comparison of
Body Composition
Analysis
Methods in Clinical Routine. Ann Nutr Metab 2000;44:243–248
13. Gwinup, G.,
Chelvam, R., & Steinberg, T. Thickness of
subcutaneous fat and activity of underlying muscles. Annals of Internal Medicine, 1971, 74, 408-41 1.
