SPOT REDUCTION: SCIENCE PROVES YOU CAN’T SPOT REDUCE FAT!

IS SPOT REDUCING REAL?

Want to get rid of fat around your stomach? Do lots of crunches to burn belly fat! The idea that you can lose body fat by specifically targeting a certain muscle group has been around for decades. Back in 1986, a study looked at the dominant swinging arm (i.e., forearm) in tennis players compared to the non-dominant arm that was used and found that the dominant swinging arm had greater muscle and less fat.(1)  This suggested that consistent training of a specific bodypart can lead to greater increases in fat loss, and thus spot reduction may be possible. The theory is that exercising a specific muscle can increase blood flow and lipolysis (i.e, fat burning) to a localized region.

IS SPOT REDUCTION A MYTH?

A 2017 study had subjects train with either upper or lower body resistance exercises for 8-weeks. The upper body resistance exercises were followed by 30-minutes of cycling. The lower body resistance exercises were followed by 30 minutes on an arm-ergometer. At the end of the study, the group that performed upper body exercise first resulted in greater fat loss in the upper limbs compared to the lower limbs. Conversely, the group that performed lower body exercises first resulted in greater fat loss in the lower limbs compared to the upper limbs. This suggests that intense resistance exercise training in a targeted area first may contribute to a greater fat loss in that region. (6)

SPOT REDUCTION STUDIES-CONT.

Over the years, there has been much controversy around spot reduction and if it is possible to target a certain muscle group for specific fat loss. The differences in study results may be attributable to differences in body fat measurement. For example, a 7.5% reduction in fat was noted in the trained arm compared with the non-trained arm when subcutaneous fat was measured in the biceps with a skinfold caliper. In contrast, when MRI was used to measure arm subcutaneous fat volume, the reduction was nearly 3-fold lower (2.8%)(2).

A 1984 study determined whether increasing the number of sit-ups each day would reduce abdominal body fat. The 27-day study on Day 1 consisted of sit-ups with 10 sets of 7 reps with 10-second rest intervals. The number of sit-ups gradually progressed to 14 sets of 24 on Day 27. The total number of sit-ups through the 27 days was 5004. At the end of the study, there was no difference in fat loss from pre to post-study. Body weight, total body fat, skinfolds, and girths were unaffected by the sit-ups training program.(7) This proves you can’t spot reduce fat by just doing more exercise.

SPOT REDUCTION STUDIES

A 2011 study found similar results to the study above. Twenty-four healthy, sedentary participants (14 men and 10 women), between 18 and 40 years, were randomly assigned to 1 of the following 2 groups: a control group or an abdominal exercise group. Anthropometrics, body composition, and abdominal muscular endurance were tested before and after training. The Abdominal exercise group performed 7 abdominal exercises, for 2 sets of 10 repetitions, 5 days a week for 6 weeks. The control group received no intervention, and all participants maintained an isocaloric diet throughout the study. At the end of the six weeks, abdominal exercise training alone was not sufficient to reduce abdominal subcutaneous fat and other measures of body composition. Nevertheless, abdominal exercise training significantly improved muscular endurance to a greater extent than the control group.(8)

NEW STUDY FINDS SPOT REDUCING IS BOGUS

A new meta-analysis (i.e., collection of studies) examined 13 studies on the effects of unilateral limb training (i.e., targeting a specific muscle group), compared with the contralateral limb (i.e., non-exercising limb), on the localized adipose tissue stores in healthy participants. After analyzing the data, the systematic literature review determined that spot reduction had no effect, regardless of age, gender, or fitness level. The researchers stated, “Exercise effectively reduces fat, but our meta-analysis showed that localized muscle training doesn’t significantly impact localized adipose tissue depots; in other words, we observed no spot reduction.”

The authors reiterated the fact that an acute increase in lipolysis or fat burning does not translate into a long-term reduction in body fat.(3)  For example, submaximal aerobic exercise increases fat oxidation or fat burning without changes in body fat. (4, 5) If fat loss is your goal, one should emphasize a reduced-calorie diet and whole-body exercises that burn the most calories per session.

In conclusion, the study suggests that localized muscle training (i.e., spot reduction exercise) does not affect localized adipose tissue stores, regardless of the characteristics of the population and the exercise program. Before you purchase the latest exercise equipment for spot reduction exercise, this is more likely marketing hype than actual science.

 

REFERENCES

1.         Maughan RJ, Abel RW, Watson JS, Weir J. Forearm composition and muscle function in trained and untrained limbs. Clin Physiol. 1986;6(4):389-96.

2.         Kostek MA, Pescatello LS, Seip RL, Angelopoulos TJ, Clarkson PM, Gordon PM, et al. Subcutaneous fat alterations resulting from an upper-body resistance training program. Med Sci Sports Exerc. 2007;39(7):1177-85.

3.         Ramirez-Campillo R, Andrade D, Clemente F, Afonso J, Pérez-Castilla A, Gentil P. A proposed model to test the hypothesis of exercise-induced localized fat reduction (spot reduction), including a systematic review with meta-analysis. Human Movement. 2022;23(3):1-14.

4.         Achten J, Gleeson M, Jeukendrup AE. Determination of the exercise intensity that elicits maximal fat oxidation. Med Sci Sports Exerc. 2002;34(1):92-7.

5.         Venables MC, Jeukendrup AE. Endurance training and obesity: effect on substrate metabolism and insulin sensitivity. Med Sci Sports Exerc. 2008;40(3):495-502.

6. Paoli A, Casolo A, Saoncella M, Bertaggia C, Fantin M, Bianco A, Marcolin G, Moro T. Effect of an Endurance and Strength Mixed Circuit Training on Regional Fat Thickness: The Quest for the “Spot Reduction”. Int J Environ Res Public Health. 2021 Apr 6;18(7):3845.

7. Frank I. Katch, Priscilla M. Clarkson, Walter Kroll, Thomas McBride & Anthony Wilcox (1984) Effects of Sit up Exercise Training on Adipose Cell Size and Adiposity, Research Quarterly for Exercise and Sport, 55:3, 242-247.

8. Vispute, S. S., Smith, J. D., LeCheminant, J. D., & Hurley, K. S. (2011). The effect of abdominal exercise on abdominal fat. Journal of strength and conditioning research, 25(9), 2559–2564.

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