I have just been to a seminar on a Dunedin study: comparing parents and their offspring from the Dunedin Next Generation Study, there is a 10 kg (20 lb) difference in weight. The fitness among boys is unchanged from their fathers, but for 15 year old girls there is a decrease in fitness.
There are similar findings in a recent report from The US Army.
One of the comments was that the NZ study used a cycle ergometer not run time. Run time is influences by weight more than cycling, but the trend is there. This generation is less fit.
The correlation between this and child rearing is less certain. What, in NZ, is clear, is that now that only the minority live consistently in a stable nuclear family, and there is a large set of data saying not living in this situation is bad for you.
My sons are very cautious about love, in part because of seeing these transitions, for most of their friends. The suspicion men have about having kids seems to be appropriate. There are some cautions: this analysis is from an epidemiological study’s children, and these are the cohort who had their kids young.
And the trend towards greater bod mass may relate to something else. But family structure now has to be considered as a confounding or causal factor. If causal, then the progressive narrative has caused damage.
Notice that V02 max is about the same, but running times among boys are decidedly up. So it’s not just girls that are losing fitness–I’d be curious whether the V02 max is a measurement error (harder to fudge mile times!), or whether we’ve got a case where kids back then ran, but today they….bike or swim or whatever?
Either way, my trips to Wal-Mart and memories of youth suggest to me that our “new family structures” are a major problem.
Agree about the US data, but that is Army recruits: most of whom have worked to get ready for basic training. The NZ data is not published, and is kids whose parents were in a cohort study that has been running for 45 years.
With running weight matters: when I was competitive I weighted under 70 kg (150 lb) and I’m 6 foot 2 inches.
I’m thinking that teenage kids need both parents working as a team, and enough secuirty to walk to school and home, Current family structure leads to a low trust environment and parents micromanaging their kids for “safety”. And to keep social welfare from blowing up the quarter of families that have not imploded
Safety has a huge impact on kid health.
Agreed that running scales with weight–I actually figured out I was never going to get to the D1 level when I looked at the guy next to me with the same legs I had, but with 20 lbs less in the upper body–but so does V02 max. (me then: 6’/145 lbs and 34:20 on the track–you would have lapped me had we raced, I believe) It’s oxygen/kG of body weight, no? That’s why Ken Cooper used, pretty successfully, the 12 minute test as a proxy for V02 max.