Does holding your breath make you stronger?
It won’t make you stronger in the sense
of building muscle in your heart or
diaphragm, but holding your breath while
training for certain sports has been shown
to improve the ability of your muscles to
cope with short, intense exertions. This
works by increasing the concentration of
bicarbonate in the blood, which helps to
neutralise the lactic acid produced during
anaerobic exercise. For this technique towork, you need to exhale normally and
hold your breath when your lungs are
empty, rather than taking a big breath in
and holding that. There are significant
risks, though.
A 2009 study found that free divers
who regularly held their breath for several
minutes had elevated levels of a protein
called S100B in their blood, which is an
indication of long-term brain damage. LVQA
&
Stars die because they exhaust their
nuclear fuel. The events at the end of a
star’s life depend on its mass. Really
massive stars use up their hydrogen
fuel quickly, but are hot enough to fuse
heavier elements such as helium and
carbon. Once there is no fuel left, the
star collapses and the outer layers
explode as a ‘supernova’. What’s left
over after a supernova explosion is a
‘neutron star’ – the collapsed core of
the star – or, if there’s sufficient mass,
a black hole.
Average-sized stars (up to about 1.4
times the mass of the Sun) will die less
dramatically. As their hydrogen is used
up, they swell to become red giants,
fusing helium in their cores, before
shedding their outer layers, often
forming a ‘planetary nebula’. The
star’s core remains as a ‘white dwarf’,
which cools off over billions of years.
The tiniest stars, known as ‘red
dwarfs’, burn their nuclear fuel so
slowly that they might live to be 100
billion years old – much older than the
current age of the Universe. AGuHow do
stars die?
PHOTOS: ESA/HUBBLE/NASA, GETTY X3 ILLUSTRATIONS: RAJA LOCKEYWHAT’S IN...There are two ways that hand creams act to moisturise your skin. Occlusive
agents form a barrier that traps water, while humectants attract more water to
your skin. The problem is that the humectants are water soluble, while the
occlusive agents dissolve in oil. So to get them to mix in an easy-to-use
formulation, the creams also need an emulsification system. ML...Hand Cream
PRESERVATIVES
AND FRAGRANCE
2.5 per cent
These improve the product’s shelf
life and make it smell nice.THICKENERS
5 per cent
PEG or polyacrylic acid (which may
appear as carbomer on the label) are
long polymer molecules that
increase the viscosity of the cream,
making it easier to apply.EMUSIFIER
2.5 per cent
Glyceryl stearate and stearic acid
help to stabilise the oil/water
mixture.GLYCERINE
3 per cent
Is a typical humectant used to draw
water in from the atmosphere.FATS AND OILS
7 per cent
Coconut oil, petroleum jelly or lanolin (a
waxy substance secreted by woolly
animals such as sheep) might be used
as occlusive agents that form a barrier
to block escaping water.WATER
80 per cent
Gives the cream volume and
dissolves some ingredients.