Too much, too young? Parents of endurance-running sisters, aged ten and twelve, insist they are not put their health at risk

• Kaytlynn and Heather Welsch aren’t just competing in tough races, but are often winning
• Medical opinion is divided over whether or not the girls are doing permanent damage to their still developing bodies
• The girls says they've received nasty comments from older runners who complain that they shouldn't be competing
  
• They also admit they cry when someone overtakes them

By David Mccormack

PUBLISHED: 14:34 EST, 4 November 2012 | UPDATED: 16:05 EST, 4 November 2012

Two young sisters who have competed in more than 160 endurance races over the past two years have divided sports fans between those applauding their remarkable achievements and those who fear they are doing untold damage to their still developing bodies.

Kaytlynn, 12, and Heather Welsch, 10, from Alvin, Texas aren’t just competing in these tough races, but are often winning against athletes typically 20 years older than them.

The girls admit they’ve had nasty comments from other runners who’ve told them they shouldn’t be competing at their young age and that they will hurt themselves. The sisters also say they often cry when other runner's pass them.

Champion sisters: Heather Welsch, 10, and Kaytlynn, 12, are from Alvin, Texas

Tougher than the rest: Kaytlynn Welsch, far left, isn't just competing in endurance races, but is winning against athletes typically 20 years older than her

In August, Kaytlynn won the women’s division of a major 13-mile race through Cameron Park in Waco, Texas and Heather finished third.

After that win, Kaytlynn was triumphed as a ‘12-year-old trail running phenom’ by Outside magazine.

The story provoked much debate on Twitter. Many readers found the girls inspiring, while others questioned if perhaps their parents were pushing them to do too much too young.

The girls’ mother Niki Welsch, 42, says she and husband Rodney, also 42, have gotten used to people questioning their parenting skills.

‘These people don’t know us. They’re on the outside and can’t see the inside,” she told The New York Times.

Rodney Welsch is an analytical chemist for a plastics manufacturing company, while Niki works weekends as a registered nurse for hospice patients.

As parents, Niki and Rodney like to set high standards for their daughters. Kaytlynn, in seventh grade, and Heather, in fifth, are expected to keep at least a 93 average in each subject at school.

Some people have found the girls success to be inspiring, while others have questioned if their parents are pushing them to do too much too soon

Daddy's girls: Heather, left, and Kaytlynn are pictured with their father and coach Rodney Welsch

At home, television is banned and instead a large treadmill sits beside the sofa in the family room. The girls are however allowed their own smart devices, Kaytlynn has an iPhone and Heather an iPad.

Both parents are athletic and wanted their children to be active at sports too. The girls' puny size - both are small for their ages and each weighs about 60 pounds - was a disadvantage for most sports.

However four years ago their father heard about children’s triathlons where competitors could start as young as seven and the distances weren't very long. He started to take his daughters along and was pleasantly surprised by how well they did.

In 2010, he began entering his daughters in road races of up to 10K. The girls usually beat anyone their age and outran most women in their 20s and 30s.

Since then they’ve competed in more than 160 races. Some have been over modest distances specifically for kids, but most have covered mileage meant to challenge adults.

Kaytlynn had finished two marathons and both girls have also competed in triathlons, typically involving a 500 meter swim, 13 mile cycle and 3.1-mile run.

The sisters have competed in more than 160 endurance races over the past two years

Kaytlynn, left, shows off one of her trophies, while Heather, right, takes part in a road race

The girls' preference however is for 13-mile trail runs over rough terrain, which are much tougher than a half-marathon, the comparable distance run on road.

The conditions for trail runs typically favor seasoned athletes and the woman’s race is typically won by those in their 30s or even 40s.

In triathlons and trail runs, age requirements are often set by the race director. However, many leave the decision to parents as long as they sign a waiver of responsibility.

The family have become accustomed to people questioning if all this endurance running is healthy for growing girls. As concerned parents, the Welschs have researched the risks and taken their daughters to a series of doctors.

Experts offer differing views about what impact, if any, running so many endurance races can have on their young bodies.

Some have warned that distance running can put stress on their growth plates and also delay the onset of puberty.

Kaytlynn Welsch says other kids complain she isn¿t fun because she can't sleepover at weekends because of her race schedule

The Welschs remain cautious and when the girls have complained of plains, their doctor has treated them with anti-inflammatories and recommended strengthening exercises.

As well as impact on their young bodies, there is also the impact on their childhoods.

Kaytlynn says other kids complain she isn’t fun because she can't sleepover at weekends because of her race schedule. As a result she doesn't have many school friends.

The girl’s don’t train much on weekdays, but on a typical weekend they will compete in one endurance event, and often two. They may run a 10K on Saturday and follow that with a triathlon on Sunday.

Next month, Rodney who also coaches the girls will take them to Hawaii, where they compete against the very best, running along serpentine paths through steep mountainsides at the Xterra trail run world championship.