Runner\'s World UK - 09.2019

THIRST THINGS FIRST

FLUID THINKING

SAUCONY HYDRALITE

SHORT-SLEEVE SHIRT

£25, saucony.com

Saucony’s clever ‘Grid’

construction increases

the shirt’s surface area

to boost its sweat-wicking

properties. It’s light,

hangs nicely and, as an

environmental bonus, is

50 per cent constructed

from recycled polyester.

BUFF REFLECTIVE

COOLNET UV+ TUBULAR

R-GRACE MULTI

£19.66, buff.com

A versatile protective

layer. The microfibre

fabric has superb

sweat-wicking and

cooling properties, plus

UPF 50+ protection

CAMELBAK

OCTANE 16X

£125, camelbak.co.uk

Super-lightweight

rucksack that’ll

accommodate 16 litres

of cargo. Comes with

Camelbak’s Crux

reservoir system. Mesh

straps boost breathability.

UNDER ARMOUR

SPEED STRIDE

SINGLET

£26, underarmour.co.uk

Minimal and ultra-

lightweight fabric. The

generous armholes offer

plenty of ventilation

and a greater range of

motion, while a mildly

dropped hem protects

your rear modesty.

NEW BALANCE 5 PANEL

PERFORMANCE HAT

£15, newbalance.com

NB’s ‘Dry’ fabric wicks

moisture from your

head to the outside,

complemented by the

interior sweatband and

ventilating mesh panels.

Reflective features will

ensure you stay visible

on any late-night runs.

EFFICIENT hydration is key to combating hot

race weather. First, get a more precise measure

of how much to drink via a sweat test: run for

40 minutes, ideally in similarly hot conditions.

Drink nothing from start to finish. Weigh

yourself before and after to see how much

weight you’ve lost. That weight loss in grams

equates to your fluid loss in millilitres; that’s

what you need to replace next time out.

What you drink is also important. Sweat

contains the electrolyte sodium, and the

more sodium you lose, the slower you run.

How much sodium you lose in your sweat,

however, is highly individual. ‘We’ve tested

WHILE STAYING HYDRATED

is key to maximising your

performance, a school of

scientific thinking has recently

emerged that suggests

dehydration – if managed

correctly – could actually

accelerate heat adaptation.

‘Interesting research from

New Zealand found that the

combination of heat stress and

mild dehydration helps runners

adapt to heat quicker,’ says

Cheung. In the study, nine

fit athletes cycled for 90

minutes a day for five days in

succession with elevated body

temperatures, either in a state

of euhydration (maintaining

normal body-water content) or

a dehydrated state of 1.8 per

cent water loss.

The dehydrated group

acclimatised in just five days

due to ‘a greater expansion

of plasma volume’ compared

with 10 days for the hydrated

group. Managed dehydration

may be effective but it could

be a risky strategy, so if you

do try it, keep an eye on

your urine colour to judge

dehydration levels, with

dark orange/brown being

a warning flag that you

have gone too far. And if

at any point you feel

uncomfortable, stop.

athletes with as low as 200mg of sodium per litre of sweat,

and as high as 2,000mg,’ explains Andy Blow of sweat-

testing specialists Precision Hydration. Blow says a normal

range is between 500mg to 1,700mg. ‘Your sodium level

is predominantly dictated by genetics, though it’s also

affected by heat acclimation and, to a degree, fitness level.’

You can measure yours via a medical-grade test with

Precision Hydration (precisionhydration.com) or, for a

rough guide, look for white patches on your kit after

sweaty runs. The white is sodium, so the patches are a

sign that you have a high sodium content in your sweat.

Precision Hydration (along with brands such as Nuun and

High5) offer electrolyte tablets containing a range of

sodium levels catering for ‘salty sweaters’.

COOL KIT

WORDS: JAMES WITTS. PHOTOGRAPHS: GETTY

SUMMER RUNNIN’

SEPTEMBER 2019 RUNNERSWORLD.COM/UK 043

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