The Exercise “Spot Reduction” Myth



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.