Spot Reduction for Abs: A New Study Suggests It May Be Real

Spot Reduction for Abs: A New Study Suggests It May Be Real Summary

• The study investigates the concept of spot reduction, which refers to the local reduction of subcutaneous fat due to the exercise of specific muscles. The study involved 16 overweight men divided into two groups: one performing a combination of abdominal endurance exercises and treadmill running and the other performing only treadmill running, with both groups matched for calorie expenditure over 10 weeks​.
• Participants in the abdominal exercise group experienced a significant decrease in trunk fat mass by 697 grams (3%), compared to no change in the control group, demonstrating that spot reduction may occur under specific exercise conditions​.
• The abdominal and control exercise groups showed similar reductions in total body fat mass and body weight, indicating that targeted exercises can achieve localized fat reduction without compromising overall fat loss.

Is Spot Reduction Real?

For many years, the concept of spot reduction, or the idea that one can selectively lose fat from targeted areas of the body through specific exercises, has been widely regarded as a myth in the fitness community. The prevailing belief, supported by numerous studies, has been that fat loss occurs uniformly across the entire body, regardless of the type of exercise performed.(Kostek et al., 2007; Krotkiewski et al., 1979) This belief has led many to dismiss exercises like sit-ups or leg lifts as ineffective for specifically targeting belly or thigh fat. However, a recent study by Brobakken et al. has challenged this long-held notion, providing new evidence that spot reduction might be possible through targeted aerobic endurance exercises.(Brobakken et al., 2023)

Review of the Literature on Spot Reduction

Early research predominantly supported the idea that spot reduction is a myth. Through targeted exercises, spot reduction protocols aim to decrease subcutaneous fat in specific body regions. Studies by McArdle et al. (2008a) and Kostek et al. (2007) concluded that localized exercises do not significantly alter fat deposits in targeted areas. Instead, fat loss is a systemic process (i.e., whole-body fat loss) driven by overall energy expenditure rather than specific muscle engagement (Krotkiewski et al., 1979).

These studies often utilized skinfold calipers and DEXA scans to measure body composition changes, consistently finding that targeted exercises did not lead to localized fat loss. More recent studies began to question these findings. A 2013 study failed to observe a change in DEXA-measured local fat mass in 11 men and women following 12 weeks of one-legged endurance training, performed at 10%–30% of 1RM for 80 min per session, with the untrained leg serving as the control condition, following their 12-week training intervention. (Ramírez-Campillo et al., 2013) However, these studies had limitations, such as small sample sizes and varying exercise intensities, which may have affected their outcomes.

Overview of the Study Protocol

The study by Brobakken et al. aimed to provide a more definitive answer by closely matching aerobic endurance training interventions for total energy expenditure in a randomized controlled trial. Sixteen overweight male subjects were recruited and randomly assigned to either an abdominal endurance exercise group or a control group.

The abdominal endurance exercise performed a combination of treadmill running at 70% HRmax for 27 minutes, followed by 4 × 4-minute intervals of torso rotation and abdominal crunches at 30%–40% of maximal strength. Conversely, the control group performed only treadmill running at 70% HRmax for 45 minutes. Both groups trained four days per week for 10 weeks. Participants were instructed to maintain their usual diet and avoid additional exercise during the study period. Body composition changes were measured using DEXA scans, while muscle strength was assessed through 1RM tests. Pulmonary oxygen uptake (V̇O2max) was also measured to control energy expenditure during training.

Spot Reduction May Be Real: Sit-ups Resulted in a Greater Loss of Abdominal Bodyfat

The main finding from the current study was that after 10 weeks and 40 training sessions, fat mass in the trunk decreased more (697 g, 3%) in the abdominal endurance exercise than in the control, while total fat mass and body weight decreased similarly in both groups. This study is the first to document that aerobic endurance exercise combined with sit-ups resulted in body fat loss in the abs rather than generalized whole-body fat release.

Spot Reduction May Be a Real Thing!

The findings of this study provide compelling evidence that spot reduction might be possible through targeted abdominal aerobic endurance exercises.  This contrasts with earlier studies that dismissed the idea of spot reduction. One possible explanation for these results is that aerobic endurance exercises involving the abdominal muscles may enhance local adipose tissue utilization.

Previous research has shown that upper body fat depots are more readily mobilized during moderate-intensity exercise than lower body fat depots. (Horowitz, 2003) Additionally, this study’s relatively high intensity of abdominal exercises may have contributed to increased fat metabolism in the targeted area.

Practical Applications on Spot Reduction Exercises

The results of this study have important implications for fitness enthusiasts and professionals. Incorporating targeted abdominal aerobic endurance exercises into regular workout routines may enhance local fat loss, particularly in the ab region. While spot reduction has been widely debated, this study provides new insights that could help shape more effective training protocols.

References

Brobakken, M. F., Krogsæter, I., Helgerud, J., Wang, E., & Hoff, J. (2023). Abdominal aerobic endurance exercise reveals spot reduction exists: A randomized controlled trial. Physiological Reports, 11(22), e15853. https://doi.org/https://doi.org/10.14814/phy2.15853

Horowitz, J. F. (2003). Fatty acid mobilization from adipose tissue during exercise. Trends Endocrinol Metab, 14(8), 386-392. https://doi.org/10.1016/s1043-2760(03)00143-7

Kostek, M. A., Pescatello, L. S., Seip, R. L., Angelopoulos, T. J., Clarkson, P. M., Gordon, P. M., Moyna, N. M., Visich, P. S., Zoeller, R. F., Thompson, P. D., Hoffman, E. P., & Price, T. B. (2007). Subcutaneous fat alterations resulting from an upper-body resistance training program. Med Sci Sports Exerc, 39(7), 1177-1185. https://doi.org/10.1249/mss.0b0138058a5cb

Krotkiewski, M., Aniansson, A., Grimby, G., Björntorp, P., & Sjöström, L. (1979). The effect of unilateral isokinetic strength training on local adipose and muscle tissue morphology, thickness, and enzymes. Eur J Appl Physiol Occup Physiol, 42(4), 271-281. https://doi.org/10.1007/bf00423297

Ramírez-Campillo, R., Andrade, D. C., Campos-Jara, C., Henríquez-Olguín, C., Alvarez-Lepín, C., & Izquierdo, M. (2013). Regional fat changes induced by localized muscle endurance resistance training. J Strength Cond Res, 27(8), 2219-2224. https://doi.org/10.1519/JSC.0b013e31827e8681