Buttock sagging arises from three overlapping factors: loss of muscle volume · loss of skin elasticity · descent of the fat layer. If muscle is the main cause, exercise is the most reliable answer, but stretched skin and fat that has moved down do not return even with long-term exercise. If there is no change after more than 3 months of lower-body exercise 3 or more times a week, it is time to check for factors other than muscle.
Contents
How can you tell what kind of sagging you have at home?
There are three criteria you can check in front of a mirror. If two or more of the three apply, it is likely you are in the range where exercise alone will struggle to give the change you want.
| What to check | How to look | If it applies |
|---|---|---|
| Fold line | Whether the line where the buttock meets the thigh is deep and fixed as a single line | Fat and skin have been pushed downward |
| Peak of volume | Whether, from the side, the most projecting point is below the middle | A shape where the upper part looks empty |
| Change when you clench | Whether the line comes back when you clench, or stays the same | If it stays the same, skin and fat changes are large |
In a study that graded buttock sagging in stages, evaluating 87 patients showed that sagging was more severe the higher the weight, the older the age and the greater the weight loss.[1] In other words, the starting point is looking at what caused it to come down rather than "how much it has sagged."
What causes the buttocks to drop?
The causes fall into four broad groups, and in practice two or three most often occur together.
- Loss of gluteal volume: long hours of sitting leave the gluteus maximus and medius underused and thinner, so the skin and fat above lose their support.
- Loss of skin elasticity: collagen and elastic fibers in the dermis decrease with age, and long exposure to gravity sets the skin in a stretched state.
- Weight change: losing a lot of weight in a short time leaves only stretched skin where the fat was. This is when the rear view looks flat after childbirth or rapid weight loss.
- Posture: a habitual backward-tilted pelvis makes the buttocks look flatter than they are. In this case correcting posture comes before changing the shape.
In a study that measured the buttocks of 280 people aged 15 to 85, muscle atrophy and sagging with age were more pronounced in women than in men, and the researchers suggested considering fold refinement, volume replacement and correction of the side-line curve together.[2]
How does sagging that exercise can lift differ from sagging it can't?
If loss of muscle mass is the main cause, exercise clearly works. Consistently doing moves that work the glutes directly, such as hip bridges, lunges and hip thrusts, increases muscle volume and lifts the line. With this type there is no reason to rush to surgery.
In contrast, stretched skin or a shifted fat layer is a different matter. Even as the muscle grows, the tissue covering it stays low, and sometimes only the lower volume becomes more prominent. This is the background to comments like "I exercised for a long time, but the dip at the side got worse."
The practical criterion that separates the two is time. If you have kept up lower-body exercise 3 or more times a week for 3 months or more and photos taken from the same angle show almost no change, factors other than muscle need to be looked at.
For muscle-related sagging, the effect of exercise has actually been confirmed. When 34 untrained university students were split into a hip-thrust group and a squat group and trained for 9 weeks, MRI-measured gluteal cross-sectional area increased similarly in both groups.[3]
Related readingWhich areas typical moves such as hip bridges, squats and lunges each work is covered in "Can you get an apple-shaped lifted bottom with exercise alone?" (Korean).
How do the methods compare at a glance?
| Method | Approach | Usually suits | Recovery burden |
|---|---|---|---|
| Exercise | Builds gluteal volume to lift the line | Loss of muscle mass is the main cause | None |
| Radiofrequency tightening | Contracts the stretched dermis with heat energy | Loss of elasticity rather than volume is the main issue | Low |
| Fat grafting | Harvests fat from elsewhere and injects it in divided amounts into layers lacking volume | The upper part looks empty or the side line is hollow | Moderate |
| Implant | Creates the basic framework of volume with an implant suited to the body type | Slim body types without enough fat to graft | Relatively high |
| Combined (hybrid) | Volume with an implant, edges and line refined with fat | When you want both volume and a natural line | Relatively high |
When grafting fat, a large amount is not packed into one layer; instead small amounts are injected across several layers. For grafted fat to take, blood vessels have to grow in from the surroundings, and if it is concentrated in one spot that process cannot happen.
Radiofrequency, considered when loss of elasticity is the main issue, has a reasonable evidence base. A systematic review of 23 studies on radiofrequency devices found measurable improvement in skin laxity on both the face and body, and complications were mostly mild and temporary.[4]
Related readingFor more on how implants, fat grafting and hybrid differ and what complication studies show, see "Buttock augmentation methods: implant, fat grafting, hybrid or BiVOL — which is right?".
Common myths and facts — sagging buttocks
| What many people think… | What the evidence shows |
|---|---|
| "Doing enough squats will lift sagging buttocks too." | That is true when muscle is the cause, but stretched skin and fat that has moved down do not return to place even as the muscle grows. |
| "Exercising long enough will fill in the side line too." | A hollow at the side is strongly influenced by pelvic bone structure and fat distribution, so it can even look more pronounced as the glutes grow. |
| "If it sags, you must have surgery." | If muscle plays a large part, exercise comes first; if elasticity is the main issue, non-surgical tightening comes first. The order depends on the share of each cause. |
| "All the grafted fat stays." | Some is absorbed, and the amount that remains is settled over the first few months. The proportion that remains depends on the injection method and recovery conditions. |
If you are considering surgery, what should you check?
Buttock augmentation is usually performed under general anesthesia and takes about 3 hours; patients are discharged after a one-night stay, and stitches are removed after about 7 days. However, this varies with the method and extent, so it should be confirmed in consultation.
- Avoid pressure: for 1 to 3 months, avoid sitting for long periods on hard surfaces.
- Avoid injections: do not have injections in the area during recovery.
- Maintain your weight: grafted fat responds just like other fat in the body, so if you lose a lot of weight, the volume that has settled also decreases.
In the following cases, it is better to have it checked in a clinic than to judge on your own.
- The shape is unchanged after 3 months or more of lower-body exercise
- A difference in height or size between the left and right is noticeable
- The fold is deep enough that the line shows even through clothing
- Stretched skin remains after childbirth or rapid weight loss
- An area previously injected with filler or fat feels hard or pain persists
That not all grafted fat remains has also been confirmed by measurement. When 50 women who had fat grafted only into the subcutaneous layer of the buttocks were followed with ultrasound, the fat-layer thickness, which had increased by an average of 56.5% right after surgery, had decreased by an average of 18.2% after 12 months.[5]
In consultations about sagging buttocks, I say "the yardstick is not how much it has sagged, but what kind of cause it is." In practice most cases are a mix of muscle loss and skin and fat changes, so first securing what exercise can achieve and then dealing with what remains reduces the recovery burden. If you can't decide, bring photos taken from the same angle about 3 months apart. With a record, a much more specific plan can be made in consultation.
The answer to buttock sagging depends on which of muscle, skin or fat position is the cause. If muscle is the cause, exercise; if stretched skin and fat that has moved down are the cause, exercising longer will not solve it.
🔬 Supporting research
Peer-reviewed international journal articles that support this article. Click a title to open the PubMed abstract.
- Frontiers in Physiology 2023 — randomized trial, 34 participants · 9 weeks Hip thrust and back squat training elicit similar gluteus muscle hypertrophy and transfer similarly to the deadlift. Key finding: hip thrusts and squats both increased gluteal cross-sectional area on MRI — muscle-related sagging can improve with exercise In text [3] · PMID 37877099 · DOI
- Plastic and Reconstructive Surgery 2019 — prospective study, 50 patients · 12-month ultrasound Subcutaneous-Only Gluteal Fat Grafting: A Prospective Study of the Long-Term Results with Ultrasound Analysis. Key finding: +56.5% right after grafting → average 18.2% decrease after 12 months — only part of the grafted fat remains In text [5] · PMID 30688886 · DOI
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Frequently asked questions (FAQ)
I've exercised for a long time, but the side line looks even more indented. Why?
As the glutes grow, the hollow at the side can look relatively more pronounced. This area is influenced more by pelvic bone structure and fat distribution than by muscle, so it may not fill in with exercise alone. Whether structural factors are large has to be judged by examining the shape directly in the clinic.
Which looks more natural, fat grafting or an implant?
Fat grafting tends to have the advantage in natural feel and shape. However, for slim body types without enough fat to graft, it may be hard to fill the desired volume, so the choice depends on body type and the size of the change you want.
How much grafted fat remains?
Not all of the injected amount takes. Some is absorbed and the amount that remains is settled over the first few months; the proportion varies with the injection method and individual recovery conditions, so it is hard to give a single figure.
When can I sit after surgery?
Everyday sitting is possible relatively early depending on recovery, but it is best to avoid sitting for long periods on hard surfaces for 1 to 3 months. The exact timing depends on the extent of surgery, so follow your medical team's instructions.
How can I tell whether exercise is working?
Keep up lower-body exercise 3 or more times a week for 3 months or more, and take photos in the same lighting and from the same angle to compare. If the photos show almost no change, it is time to also check for factors other than muscle.
📖 References
Click a [number] in the text to jump to its source, and ↩ to return. Only papers whose title, journal and year were verified on PubMed are listed.
- ↩ Gonzalez R. Etiology, definition, and classification of gluteal ptosis. Aesthetic Plast Surg. 2006;30(3):320-6.PMID 16733776 · DOI— evaluation of 87 patients — the greater the weight, age and amount of weight lost, the more severe the buttock sagging
- ↩ Hoenig JF, Swetje K. Age-related ptosis of the buttock: an anthropometric gender-specific analysis. Aesthetic Plast Surg. 2013;37(6):1090-9.PMID 24114293 · DOI— measurement of 280 people aged 15–85 — atrophy and sagging more pronounced in women than men
- ↩ Plotkin DL, Rodas MA, Vigotsky AD, et al. Hip thrust and back squat training elicit similar gluteus muscle hypertrophy and transfer similarly to the deadlift. Front Physiol. 2023;14:1279170.PMID 37877099 · DOI— RCT, 34 participants · 9 weeks — hip thrusts and squats both increased gluteal cross-sectional area (MRI)
- ↩ Rohrich RJ, Schultz KP, Chamata ES, Bellamy JL, Alleyne B. Minimally Invasive Approach to Skin Tightening of the Face and Body: Systematic Review of Monopolar and Bipolar Radiofrequency Devices. Plast Reconstr Surg. 2022;150(4):771-780.PMID 35877937 · DOI— systematic review of radiofrequency devices — measurable improvement in skin laxity on face and body
- ↩ Cansancao AL, Condé-Green A, David JA, Vidigal RA. Subcutaneous-Only Gluteal Fat Grafting: A Prospective Study of the Long-Term Results with Ultrasound Analysis. Plast Reconstr Surg. 2019;143(2):447-451.PMID 30688886 · DOI— ultrasound of 50 patients with subcutaneous fat grafting — average 18% decrease in fat-layer thickness after 12 months
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