2019-10-01 Australian Men\'s Fitness

OCTOBER 2019 MEN’S FITNESS 65

n Here’s the
conundrum: sun
exposure causes
about 99 percent
of non-melanoma
skin cancers
and 95 percent
of melanomas
in Australia, but
90 percent of
our vitamin D is
absorbed through
UVB radiation
from sunlight. We
get very little from
food (oily fish, sun-
dried mushrooms,
egg yolks).
In recent years,
a startling rise
in vitamin D
deficiency caused
experts to ask if
our “sun phobia”
has gone too
far.Clothesand
glassblockUVB
radiation,and
sunscreenscut
95 percentof
UVB.Soyoucan’t
getvitaminD
sittinginfrontof
a closedwindow
ona sunnyday,
butyoucanstill
getdamagefrom
UVAradiation,
whichcanlead
toskincancer.
Carwindscreens

block 98 percent of

UVA, but car side

windows and most

building glass

can let in up to 79

percent of UVA.

“Sensible” sun

exposure and a

check of the UV

index on weather

reports can help

to protect you.

You can maintain

vitamin D levels by

exposing one large

area of the body

(belly, back or legs)

to direct midday

sunshine in winter

(or mid-morning or

mid-afternoon sun

in summer) for 10

to 15 minutes – that

is, when the UV

index is about 3 or

less.It’ssafetobe

withoutprotection

atthisUVlevel

unlessyou’re

outinthesunfor

hours.Peoplewho

havedarkskin,

areobese,have

osteoporosisoreat

low-fatdietsare

moresusceptible

toD deficiency,so

theyneedlonger

inthesun,asdo

peopleinthefar

southofAustralia.

Smart devices

Problematic mobile use can hurt mental

health in similar ways to substance

abuse and gambling addiction.

nThere’snodoubt

verylow-carbdiets

(max 10 percent

energyintake

fromcarbs),work

forweightloss...in

theshortterm.But

mediumandlong

term,thesediets

don’tseemtoresultin

fasterweightlossor

better maintenance

than regular energy-

restricted diets.

Not everything that

causes weight loss or

apparent metabolic

improvement in

the short term is

a good idea. Take

cholera, for instance.

Limiting intake of

wholegrains, fruit

andstarchy veg can

alsocut out many

sources of fibre and

essential vitamins

andminerals.

Carbsare the

mostconvenient

sourceof energy

forthebody, which

meansan active guy

has a greater need

for them than an

inactive guy. At low

intensities, exercise

performance may

not decline severely,

but a diet lacking

carbs can hit you

with headaches,

nausea, fatigue,

poor concentration,

constipation and

bad breath if you’re

doing moderate

to high-intensity

activity. It also hurts

your immunity and

recovery, especially

if time between

training sessions is

less than 8-12 hours.

Bottom line: your

carb intake should

be matched to your

training intensity

and duration. Daily

recommendations

for athletes is 5-7g/

kg for moderate

intensity (1 hour/

day), increasing up to

8-12g/kg for extreme

endurance exercise.

Sun exposure

Low-carb diets

Aim for 5-7g carbs

per kilo of body

weight when

doing moderate-

intensity exercise.

5-7

n The good news – the US National

Cancer Institute says there’s no

consistent evidence that non-ionising

radiation from modern mobile phones

and tablets increases cancer risk.

Even better, a study reported this year

that suggested teens were developing

horn-like bone spurs on their neck from

looking down at screens was ridiculed

around the world. The bad news is

that “text neck”– a painful condition

from looking down at screens – is real.

Mobiles also increase illness due to

germs (one source claims 1 in 6 phones

has poop on it) and research indicates

that texting and driving can be just as

dangerous as drinking and driving.

The greater risk is that problematic

mobile use can hurt mental health

in similar ways to substance abuse

and gambling addiction. The average

person spends over four hours a day

on their device. For some, that might

be essential. For others, it’s a problem.

Maybe you’re not an addict, but your

habit is hurting your relationships

or making people think you’re a dick

(there’s a study on this, for real).

The surest signs of addiction are the

reactions when your phone or network

is unreachable – anger, tension,

depression, irritability, restlessness.

If you turn to your phone when you have

unwanted feelings such as anxiety or

depression, that’s a dependence issue.

If you completely lose track of time

when you use and you put a relationship

or job at risk due to excessive phone

use, that’s over the line of “moderation”.