More than 1.7 million New Zealanders have contracted Covid-19 since the pandemic began, and according to research from the World Health Organisation around 10 percent will develop Long Covid.

Researchers are calling for funding to directly support investigations into the impact of Long Covid on young Kiwis.

The last four months have been a rollercoaster for 14-year-old Jaime Warrington and her family.

After a school trip in April she got Covid-19. Weeks later the extreme fatigue was still lingering.

"I was just getting tired from doing everyday things, on Saturdays we play netball and after every game I came home and then I'd just be in bed and after every day of school I came home and I'd be straight in bed."

Then things deteriorated even further.

"I had cross-country training and my heart rate went up to 206 and I was hallucinating, I was on the verge of passing out, I couldn't see anything, it was quite scary."

They booked a doctor's appointment to try and find some answers. Finally they had confirmation - she was battling Long Covid.

Jaime's mother Jane says after seeing multiple doctors they were given the same advice around exercise - to build things back up over six weeks.

But that made things worse.

"She was just coming back exhausted, having breathing problems, her heart rate had really escalated."

Immunologist Dr Anna Brooks says while Long Covid is less common in children, they should not be pushed back into exercise, no matter how sporty they are.

"We don't know how long it will take to get through, but we do know that pushing could make your symptoms worse and your recovery slower."

She is researching Long Covid in adults with a crowdfunded study to try and fast-track some answers.

Meanwhile, there is no treatment, but Dr Brooks says parents and teachers should look out for symptoms in children.

"It might be a child that comes home from school and is very exhausted, or they might be, you know, grumpier than normal, they might be rashy, they might have complaints of a sore tummy, the symptoms spectrum can be quite vast."

She says urgent research into Long Covid in children needs to be prioritised.

In a statement, a spokesperson from the Ministry of Health says: "The ministry's currently working to assess the longer term impact of Covid-19 on people in Aotearoa".

"Part of this work also includes a study with Victoria University to understand the experiences of people who have had Covid-19, although this work is not specifically focused on children, an aspect of the study also focuses on the impact on families and whānau, which may include our tamariki."

Earlier this year, the ministry launched a Covid-19 research fund, the results of which will be made public later this year.

A key priority theme for the fund was Long Covid in adults and children.

Now, life has slowed down completely for Jaime. Weeks once jam-packed with sports, school and socialising are no longer.

She spends most of her time in her room at their family home in Maungaturoto, with only about an hour of school work manageable each day.

"[You] just can't remember what you're reading and it's very foggy, sometimes when you're trying to form a sentence you like, can't find the word that you need."

That was on top of difficulty breathing and heart palpitations.

The change of pace was taking a toll.

"It's quite scary, honestly, it's definitely been a rollercoaster and there has been a lot of tears from everyone."

She's desperate to get back to school at Otamatea High for term four with crucial assessments piling up and to slip back into her role as captain of the netball team.

Until then, more rest was on the cards - and she has a message for other sporty teens: "Don't get back into things quickly, because it's really dangerous".

-RNZ/Lousie Ternouth.