Most growth plates close by the early 20s, but standing tall is more than inches: posture, strength and strong bones are yours to build at any age. People often link certain ages with certain milestones, so it's no surprise that one of the most common questions we hear is, "Can I still grow at 25?"

The honest answer for most adults is no: once growth plates have fused, bones can't grow longer. What can still change is how tall you stand and measure, through posture, spinal health and even the time of day (most people measure a little more in the morning than in the evening). Let's look at why growth stops, which factors shape height, and what is still in your hands.

Why Do We Stop Growing?

See, height in humans is a direct link to how long our bones get. Bones (long bones to be specific) have what are called the "epiphyses or growth plates." These growth plates respond to hormones like the growth hormone, thyroid-stimulating hormone, and sex hormones by increasing in length.

After the growth spurt associated with puberty, the production of the aforementioned hormones reduces, and the growth plates of long bones fuse. This typically occurs around the age of 16 for women and somewhere between 14 and 19 for men.

So after growth plates fuse, bones no longer grow in length. That is a normal part of development, and it is when the focus naturally shifts from growing to keeping bones strong.

Factor 1: Genetics

Genetics is the single biggest factor in a person's height. Twin studies estimate that it accounts for roughly 80% of the differences in height between people. Genes are not something we choose, which frees us to focus on the habits we can shape.

There is a rough calculation that parents can do to determine a child’s height. It is called the “mid-parental height”

• Step 1: add the height of the mother and the father.
• Step 2: divide the total by 2
• Step 3: for a boy, add 2.5”; for a girl subtract 2.5”

It is important to note that this is only a rough estimate, not a prediction set in stone. Many other factors play a part, as the sections below show.

Factor 2: Nutrition

After genetics, nutrition is the next big influence on height across whole populations. Good nutrition in childhood and adolescence supports normal growth.

Protein is a key building block, along with minerals like calcium, phosphorus and potassium, and vitamins like vitamin D.

For adults, these same nutrients help maintain bone density and strength, which supports good posture and healthy bones for years to come.

Factor 3: Sleep

Sleep plays a real role in healthy development. While many bodily functions slow down during sleep, the body releases much of its daily growth hormone during deep sleep.

Research on sleep and growth in children shows that regular, sufficient sleep supports healthy development. Different age groups have different sleep needs.

So before you go sleeping the whole day, here is a table that contains the CDC's recommended sleep requirements per day for the different age groups. For the sake of this article though, teens are recommended to have about 8-10 hours of sleep every 24 hours and 20 – 30-year-olds need 7 hours or more per night.

Factor 4: Exercise

Regular exercise supports healthy development in young people and keeps bones and muscles strong at every age. Exercises that involve stretching and core strength also improve posture, which can help you stand at your full natural height.

Stretching, yoga and strength training work the elasticity of muscles and tendons and help you hold your spine upright. Poses like Surya Namaskar and the Cobra are popular ways to build flexibility and posture.

Much of your height depends on factors you cannot control, like your genes. Many other factors, such as food, sleep, activity and posture, are within your control.

After 25, the goal shifts from growing longer bones to keeping the ones you have strong. With balanced nutrition, enough sleep, regular exercise and good posture, you can stand at your full height and build bones that support you for decades.

References

1. Elham Karimian, Andrei S. Chagin, Lars Sävendahl. Front Endocrinol (Lausanne) 2011; 2: 113. Prepublished online 2011 Oct 31. Published online 2012 Jan 9. doi: 3389/fendo.2011.00113
2. Crowder C, Austin D. Age ranges of epiphyseal fusion in the distal tibia and fibula of contemporary males and females. J Forensic Sci. 2005 Sep;50(5):1001-7. PMID: 16225203.
3. Is height determined by genetics? (2020). nlm.nih.gov/primer/traits/height
4. Perkins JM, et al. (2016). Adult height, nutrition, and population health. DOI: org/10.1093/nutrit/nuv105
5. Sleep and weight-height development, Jornal de Pediatria, Volume 95, Supplement 1, 2019, Pages 2-9, ISSN 0021-7557, https://doi.org/10.1016/j.jped.2018.10.009. (https://www.sciencedirect.com/science/article/pii/S0021755718310192)
6. Sleep and Sleep Disorders https://www.cdc.gov/sleep/about_sleep/how_much_sleep.html
7. Effect of Regular Yogic Training on Growth Hormone and Dehydroepiandrosterone Sulfate as an Endocrine Marker of Aging.            Sridip Chatterjee and Samiran Mondal
8. Borer KT. The effects of exercise on growth. Sports Med. 1995 Dec;20(6):375-97. doi: 10.2165/00007256-199520060-00004. https://pubmed.ncbi.nlm.nih.gov/8614759/

Sources

1. Silventoinen K, et al. Heritability of adult body height: a comparative study of twin cohorts in eight countries. Twin Res. 2003;6(5):399-408. doi:10.1375/136905203770326402. doi.org/10.1375/136905203770326402