My daughter has recently joined a gym and a pilates class. No one is happier than I am. So much so that I am digging deep and paying for them: she's saddled with student debt. This is the daughter who tolerated PE at school and did no exercise at all out of school; my invitation to go for a bracing walk was met with, "But I don't have the right shoes."
With a staggering one in three girls and one in four boys classed as obese by the age of nineteen - and that's medically obese, not simply overweight – isn't it every parent's duty to try to get their child moving?
So how much did you get this week?
We're talking exercise: a good half hour every day – or none at all?
The recommended minimum amount is 30 minutes, five times a week. You should do enough to get sweaty and slightly breathless. Shockingly, nearly 70% of us do not do this.
For a lot of people, memories of PE at school put them off exercise forever. I remember only too well the twice-weekly torture: shivering on the hockey pitch with blotchy purple legs, then baring my pubescent body in the communal shower, all under the eye of the teacher in a warm track suit. Could anyone one think of a better way to turn young girls off sport?
Sophie's experience echoes this. "I hated PE at school! I was one of those kids who was always picked last when we played rounders and just wasn't very sporty. When I went up to secondary school I couldn't stand how seriously they took it."
Sophie hated PE so much that she managed to wriggle out of it - for four years. "I got my mum to write me a note to get me out of it and I didn't do PE again."
Not everyone is good at team sports, or competitive sport, but there is usually something that everyone can enjoy - even Sophie admits to this. "I love swimming and walking now. I never tell my step-children how much I hated PE and encourage them to be outside exercising whenever possible."
But the biggest influence on how much kids love sport is parental attitude. The couch potato syndrome really is catching. Kids love role models.
As Professor Neil Armstrong who established the Children's Health and Exercise Research Centre at Exeter University explains, "It's no good a mother saying when 'I was your age I used to play netball and hockey', she has to set a good example now, for instance using the stairs, rather than an escalator."
There is plenty of evidence to show that if mums exercise, the likelihood of their daughters doing the same increases. Both mums and dads are role models, but the amount of exercise girls do once they reach the age of nine drops dramatically. In the same way that nagging your child to eat healthily, whilst stuffing your face with doughnuts doesn't work, neither does nagging about exercise.
Maggie Ayre is the UK's only fitness coach who specialises in coaching teenage girls. Her own experience of PE at school was "I hated it." But Maggie confirms that if teenagers - and especially girls - can be introduced to a range of sports instead of traditional PE activities, they can change their "I don't do exercise" belief.
Maggie's sport is sailing and she eventually reached almost Olympic standard. Maggie adds, "There is also a growing body of evidence that active bodies lead to better concentration, increased participation and better grades for schools."
It's not a case of running the marathon. Every little helps. If you use the car for the school run when school is less than a mile away, what kind of message does that convey? Okay, you might have to get out of the house 15 minutes earlier and not be able to drive straight to work - but think of the health benefits: 15 minutes twice day and that's your exercise sorted. Just do it.