If you have teenagers or were once a teenager yourself, you’ve probably experienced this. Your child’s jeans may have fit perfectly in September, but by December they’re showing their ankles. Growth during adolescence can seem surprisingly rapid, with some teens growing 4 to 5 inches (10 to 13 centimeters) per year. But is this really humanity’s most rapid period of growth?
Surprisingly, that’s not the case. The teenage growth spurt is only the second-fastest a human can grow.
you may like
Your baby’s height increases by nearly 1 foot (25 to 30 centimeters) per year. This is more than twice the rate of the most dramatic growth spurts during the teenage years.
In fact, Adam Baxter-Jones, a professor in the Department of Kinesiology at the University of Saskatchewan in Canada, told Live Science that in girls, “they reach 50 per cent of their adult size in 18 months.” Boys reach 50% of their adult size by 24 months.
After that, things slow down. “As we move into late infancy and childhood, physical growth takes a backseat,” Cumming says.
From the age of 4 until adolescence, height growth slows to about 2 to 2.5 inches (5 to 6 centimeters) per year, Baxter-Jones said. At this time, humans reach their second fastest growth phase.
At the peak of puberty, girls grow an average of 3.5 inches (9 centimeters) a year, and boys grow an average of 4 inches (10 centimeters) a year, according to a study published in the Journal of Adolescent Health.
However, these average peak growth rates are just averages.
“If you measure it regularly enough, you’ll see a period of very intense growth, and then your body will adapt,” Cumming said. “You can check the speed up to a maximum of about 20 centimeters.” [nearly 8 inches per year] In some of the studies we looked at…of course, if you average over a period of time; [you get] 10-12cm [4 to almost 5 inches] Year by year. ”
you may like
Just like when you’re a baby, girls experience a growth spurt earlier (around age 11). Boys, on the other hand, typically enter puberty about two years later.
“Boys typically experience a slightly more intense growth spurt,” Cumming says. “That’s because they not only produce more growth hormone, but also testosterone, which contributes to bone length.”
The adolescent growth spurt stops around age 16 for girls and 18 for boys. Both boys grow faster and have about two years longer growth period, which makes them taller on average.
The age at which a growth spurt is reached has no effect on final height. People who mature early stop growing sooner than people who mature later, so those who mature later have more time to grow, Baxter-Jones said.
Growth spurt and body shape
Growth spurts occur from the outside in. “First the feet and hands, then long legs and long arms. So when you look at kids at the beginning of puberty, they look like baby giraffes. They have these big clown feet, legs that last forever,” Cumming said.
The torso grows last. When children grow slowly, their torso may not fully catch up with the rest of their body. As a result, in sports like ballet and gymnastics, teams choose late-starters with more straight physiques and long legs, Cumming says. However, early developers have their own athletic advantage.
“The earlier they go through their adolescent growth spurt, the bigger and stronger they become. Those kids are the ones who get selected for all the top positions and get into the top academies,” Cumming said. “At Scottish Academy, we surveyed over 1,000 children aged 14 and over and found no late developers.”
But that rapid growth comes at a price. Rapid growth causes bones to become weaker and more susceptible to damage.
“The bone grows and then it becomes mineralized, with a gap of about nine months,” says Baxter-Jones. “The peak fracture rate occurs during the adolescent growth spurt.”
It also takes up to nine months for muscles and tendons to catch up with bone growth, which can lead to growth-related injuries, especially around the heels, knees, and hips.
However, carefully monitoring growth spikes can help prevent more serious problems. “If we do this in Premier League academies, we can reduce non-contact injuries by around 70%,” Cumming said.
For parents wondering whether their child’s growth pattern is normal, both experts emphasized that wide variation is to be expected.
“It’s normal to grow quickly, but it’s also normal to grow slowly,” Baxter-Jones says. The final height of an adult is determined by genetics. Rarely, there are also childhood disorders, such as pituitary gigantism, that lead to overproduction of growth hormone. Children with the disease can grow up to 6 inches (15 cm) per year, with one report stating that a 13-year-old boy grew 7.5 inches (19 cm) per year. But even this rapid growth is slower than a baby’s growth rate.
So what is the fastest rate a human can grow? The answer is not when you’re a teenager and growing out of your jeans, but when you’re too young to remember it ever happening.
Source link
