It's that time of year again and it's a harsh test of fitness...
This week we are on air at the later time of 2pm - we follow the London Marathon, and as a keen - but not that keen - runner, I salute those doughty souls (or should that be soles?) who are tackling the 26 mile course.
And because they're keeping fit, they're doing us all a favour.
We, as a nation, are in a weighty crisis, according to the government.
Even seeing the scales is a problem for so many
The figures are frightening.
In England alone, nearly a quarter of men and women are now obese, and the statistics for children are even more worrying.
And it costs money, both in direct terms to the NHS, and to the broader economy in terms of days taken off sick - around £16bn, according to a government report.
In times of crisis, people tend to turn to the government for action, but should they?
Should the government be taking radical steps for our own good?
Perhaps putting cigarette style warnings on packets of butter, or VAT on unhealthy food?
Alan Johnson - an eye on government obesity policy
Or should they - pardon the pun - butt out, leaving it up to the individual to take responsibility for their weight?
This week, we've taken the unusual step of unleashing two reporters on the same subject.
Gillian Hargreaves will be making the case for fighting fat, Max Cotton will be flying the flag for individual responsibility.
Who knows who'll come out on top?
I'll be chewing the fat live with the Health Secretary, Alan Johnson.
Biofuels - transport panacea?
The RSPB is against the principle of biofuels...
And for a while, biofuels looked like the silver bullet in the climate change debate- a way of powering cars without burning fossil fuels.
From 15 April, 2.5% of everything we put in our petrol tanks will be biofuel - that's essentially fuel sourced from animal or vegetable material - but is it a good solution?
A growing number of voices say it isn't, and that at a time of rising food prices, land shouldn't be given over to crops for fuel.
Paola Buonadonna will be separating the wheat from the chaff, and I'll talk live to the Green Party's Adrian Ramsay.
That's all at 2pm on Sunday. Keep on running.
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