British Olympians Becky and Ellie Downie say abusive behaviour in gymnastics training became "ingrained" and "completely normalised".
It comes after several gymnasts told BBC Sport about what they called a "culture of fear" within the "mentally and emotionally abusive" sport.
The Downies said they had previously been afraid to speak out.
"We certainly didn't realise how wrong it was at the time," they said.
The World Championship medallists, both current members of the GB squad, added in a statement on Twitter: "It's taken years and years to understand and come to terms with it.
"While exact experiences obviously vary, we both recognise the environment of fear and mental abuse those before us have described so bravely.
"For too long, the health and wellbeing of young girls has been of secondary importance to a dated, cruel, and - we'd argue - often ineffective culture within women's gymnastics training."
On Tuesday, British Gymnastics announced an independent review will take place following allegations of mistreatment from a number of athletes in recent days.
The governing body told BBC Sport on Thursday: "The behaviours we have heard about in recent days are completely contrary to our standards of safe coaching and have no place in our sport.
"It is clear that gymnasts did not feel they could raise their concerns to British Gymnastics and it is vital that an Independent Review helps us better understand why so we can remove any barriers as quickly as possible.
"This review will ensure that all those with concerns about safeguarding and abuse have the correct and proper channel to raise any issues."
'Deep scars which will never be healed'
Ellie Downie, 20, says she has been made to feel "ashamed" of her weight for almost all of her career, and to this day "still hides food".
"This never-ending focus on my weight has left deep scars which will never be healed, I suspect," she said.
"After a deep emotional battle, I've finally found a place to be happy with my body outside of the gym, but I'll always feel overweight whenever I'm in a gymnastics setting.
"We've seen too many girls descend into eating disorders and mental health problems because of this, and while this is changing, there is still a culture of less is best."
Her older sister Becky, 28, said it is only over the last few years that she has felt strong enough to "stand up for herself", adding that they are "no longer routinely weighed".
They say they have raised their concerns and shared their experiences with British Gymnastics.
"We're speaking out now, just a year before the peak of our sport, the Olympic Games, because we have a duty to the wellbeing of the young children coming into gymnastics, and their safety is more important than any Olympic medal."
They added: "We hope by speaking up today, we'll not only support those who have already done so, but also encourage others who may want to, but have so far felt unable to do so.
"We'll do everything in our power to see the sport showcase itself for what it should be: a place for boys and girls to have fun, be healthy and take it as far as they want to on their own terms."
UK Sport 'knew of abuse allegations'
The BBC has learned that UK Sport knew of allegations of abuse in gymnastics as recently as summer 2019.
After several gymnasts spoke out earlier this week, UK Sport, which funds Olympic sports in the UK, responded saying the allegations were "shocking and upsetting".
But the BBC has seen emails from last year in which two different parents separately emailed UK Sport's Head of Integrity in June and July 2019 regarding different allegations around safeguarding and alleged abuse.
A face-to-face meeting was due to take place between the head of integrity and one parent - but was later cancelled by UK Sport.
That parent said in an email: "I still hope that one day someone will finally listen and prioritise the welfare of children over medals. Perhaps you will be that person?"
A spokesperson for UK Sport told the BBC: "There is absolutely no place in sport for abuse or bullying of any description.
"It is important to note that UK Sport doesn't have the authority to intervene in employment matters within a sport, but we are absolutely committed to draw on all available measures to ensure that the high performance system is a safe environment for all athletes."