UPDATE: Spot Reduction: Probably Possible, But With Constraints

For years, we as an industry told clients that spot reducing fat wasn't possible. Based on the evidence at the time, we were correct. However, now with updated research, there might be an asterisk on that sentence - a potential set of criteria that MIGHT allow us to preferentially lose body fat from a target area.

Local exercise does appear capable of increasing local lipolysis, and a small number of intervention studies now suggest that under the right conditions this can translate into measurably greater fat loss from the region being trained. The important distinction is that this is not an alternative to overall fat loss. At best, it appears to be a way of slightly influencing where some of that fat loss occurs while the individual is already losing body fat systemically.

1. Mechanistically, why could spot reduction work?

Contracting skeletal muscle changes the local environment around it. In the classic Stallknecht study, one leg performed knee extension while the other remained inactive. Blood flow and lipolytic activity in subcutaneous fat adjacent to the contracting muscle were generally greater than in fat adjacent to the resting leg. In other words, spot lipolysis is real, even if spot fat loss over weeks is a separate question.

The proposed mechanism is fairly straightforward. Training a muscle increases local temperature and blood flow and exposes nearby adipose tissue to a more lipolytic environment. Catecholamines and potentially muscle derived signaling molecules may contribute to greater liberation of fatty acids from nearby adipocytes.

However, mobilizing fat is not the same as losing fat. Once fatty acids leave the adipocyte, they still have to be oxidized. If energy demand is insufficient, those fatty acids can simply be re esterified and stored again. That is one reason concurrent training models, where localized resistance or endurance work is followed by aerobic exercise, are particularly interesting.

So the hypothetical sequence is:

Targeted muscle contraction → increased local blood flow/lipolysis → fatty acid mobilization → subsequent energy expenditure → oxidation rather than re storage.

2. The Research

Scotto di Palumbo et al., 2017

Sixteen inactive women completed eight weeks of training. One group performed upper body resistance training followed by 30 minutes of cycling, while the other performed lower body resistance training followed by 30 minutes of arm ergometry. Train one region first to potentially mobilize fatty acids locally, then perform aerobic exercise using a different region to increase systemic oxidation without continuing to preferentially stress the targeted muscles.

The results followed the predicted regional pattern. The upper body resistance group lost considerably more fat from the upper limbs than lower limbs, while the lower body resistance group lost considerably more fat from the legs than arms. Importantly, overall fat loss was similar between groups. That is exactly what we would expect if spot reduction does not create extra fat loss out of nowhere, but instead changes the distribution of a similar amount of total fat loss.

Paoli et al., 2021

Fourteen healthy adults completed either a spot reduction style mixed circuit or traditional resistance training. The spot reduction protocol alternated targeted resistance exercise with aerobic work.

The spot reduction group showed reductions in abdominal subcutaneous fat by ultrasound and skinfold measurements. However, the same effect was not seen consistently at the triceps. The authors also noted substantial variability, small sample size, and measurement limitations.

This suggests:

Regional fat loss may be influenced by training.
The effect is probably not equally reliable at every body site.

Abdomen, arms, thighs and gluteofemoral fat differ physiologically, hormonally and in receptor distribution, so assuming a universal response would be premature.

Brobakken et al., 2023

Sixteen overweight men were randomized to either treadmill running alone or treadmill running plus abdominal endurance exercise, with total training energy expenditure closely matched. The abdominal training group performed treadmill exercise plus torso rotation and abdominal crunch work four days per week for 10 weeks. Both groups lost similar amounts of total fat, but the abdominal exercise group lost about 697 g more trunk fat, representing approximately a 3% between group difference in regional fat loss.

That is important because it addresses one of the largest weaknesses of older spot reduction studies: often there was little meaningful total fat loss to begin with. Here, systemic fat loss occurred in both groups while regional trunk fat loss differed.

3. Why Earlier Research Often Found Nothing

The more recent positive studies tend to combine several features that the negative studies often lacked:

meaningful total energy expenditure,
repeated training over 8–10+ weeks,
an actual reduction in total body fat,
localized muscular work,
and aerobic activity to increase subsequent oxidation.

That combination may be the key.

I would currently describe spot reduction as biologically plausible and experimentally supported, but not established strongly enough to become a major fat loss strategy. You probably have some ability to bias fat loss toward a region, but the effect is secondary to overall fat loss and likely modest compared with genetics, sex, total body fat, energy balance and individual fat distribution.

You are not going to crunch your way from 20% body fat to visible abs while eating at maintenance.

But if you are already dieting successfully, there may be ways to marginally influence where some of that fat is mobilized.

Criteria for Spot Reduction to Have a Reasonable Chance of Working

I would want essentially all of the following conditions present before considering this worthwhile:

1. You are already losing body fat. Spot reduction appears to influence distribution, not circumvent energy balance. If body weight and total fat mass are not trending downward, I would not expect localized training to rescue the process.

2. The target area is trained immediately before or during meaningful energy expenditure

The strongest protocols either trained the target region before cardio or interspersed target work with aerobic exercise.

3. The localized work creates enough muscular activity to meaningfully alter local physiology. Light, token sets are probably not enough. The literature has used everything from relatively low load abdominal endurance work to more explosive resistance exercise, so I would not say heavy >70% 1RM work is proven necessary. What seems important is enough repeated contraction to meaningfully increase local demand, blood flow and metabolic activity.

4. There is enough subsequent aerobic work to oxidize mobilized fatty acids. Mobilization without oxidation gives those fatty acids an opportunity to simply be stored again.

5. The intervention lasts long enough to detect a difference. The positive longitudinal studies generally lasted around 8–10 weeks.

6. The protocol does not compromise the athlete's primary goal. If someone wants a smaller waist, aggressively hypertrophying the obliques to theoretically increase abdominal spot reduction may produce the opposite visual outcome. Likewise, adding substantial exercise volume simply to chase a small regional fat loss advantage could impair recovery or interfere with hypertrophy.

Proposed Practical Protocol:

3–4 sessions per week targeting the desired region.

Step 1: Localized training

Perform approximately 10–20 minutes of meaningful work for the musculature underlying or adjacent to the desired fat depot. The goal is repeated muscular contraction and local metabolic demand without creating excessive fatigue or compromising normal resistance training.

Step 2: Immediately follow with aerobic exercise

Perform 25–40 minutes of moderate intensity aerobic work.

A reasonable practical target would be approximately 60–70% HRmax or roughly RPE 4–6/10.

Where practical, I would favor cardio that does not heavily fatigue the same target musculature.

Step 3: Maintain the actual fat loss intervention

The athlete still needs:

a sustainable calorie deficit,
sufficient protein,
resistance training,
appropriate recovery,
and enough time for meaningful total body fat reduction.

For the average person trying to lose fat, I would probably not complicate the program with this. For an advanced physique athlete who is already doing everything else correctly and has a stubborn region that meaningfully affects stage appearance, I think the evidence is now strong enough that a well designed 8–10 week trial is reasonable. The cost is relatively low, the physiology is plausible, and several controlled studies now point in the same direction.

References:

Scotto di Palumbo A, Guerra E, Orlandi C, Bazzucchi I, Sacchetti M. Effect of combined resistance and endurance exercise training on regional fat loss. J Sports Med Phys Fitness. 2017;57:794–801. DOI: 10.23736/S0022-4707.16.06358-1. Minerva Medica

Paoli A, Casolo A, Saoncella M, et al. 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;18:3845. DOI: 10.3390/ijerph18073845. DOI.org

Brobakken MF, Krogsæter I, Helgerud J, et al. Abdominal aerobic endurance exercise reveals spot reduction exists: A randomized controlled trial. Physiological Reports. 2023;11:e15853. DOI: 10.14814/phy2.15853. PubMed Central (PMC)

Stallknecht B, Dela F, Helge JW. Are blood flow and lipolysis in subcutaneous adipose tissue influenced by contractions in adjacent muscles in humans? Am J Physiol Endocrinol Metab. 2007;292:E394–E399. DOI: 10.1152/ajpendo.00215.2006. Physiology Journals

Henselmans M. New science: spot reduction is not a myth. Interpretive review of the literature.

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UPDATE: Spot Reduction: Probably Possible, But With Constraints