Cycling Weekly — February 08, 2018

(Jacob Rumans) #1

Fitness


Supplements: do you really need them?


Sports nutritionist Anita Bean dispels the snake-oil and hype, and lists the few
genuinely effective dietary supplements that might actually help you

The vast majority of sports supplements have no evidence backing their claims. They are
at best unnecessary, at worst harmful or illegal. That said, there are a few products that
are supported by a peer-reviewed body of research. If you are subject to anti-doping rules,
then make sure that your supplements come from a reputable company that provides a
certificate to prove it has been batch-tested for banned contaminants by a recognised
sports anti-doping lab. Look for the Informed Sport logo on the label and check the batch
number on the Informed Sport website.

VITAMIN D


Low levels can result in impaired muscle function, weak bones and depressed
immunity. Your GP should be able to test your vitamin D level; if it’s less than
50nmol/l, then you will benefit from a supplement (100 micrograms per day is the upper
limit). However, if testing is not available to you, Public Health England recommends taking
a daily 10-microgram supplement during autumn and winter.

IRON


If you have been diagnosed with iron deficiency, then you’ll benefit from iron
supplements. Symptoms include persistent tiredness, fatigue, abnormal breathlessness
during exercise and loss of endurance and power. Your doctor can carry out a simple blood
test and will prescribe supplements if you need them.

BETA-ALANINE


Beta-alanine may enhance sprint performance and benefit efforts of one
to four minutes duration, and those involving repeated sprints. It increases
carnosine concentration in the muscle, which increases buffering capacity and helps offset
the build-up of metabolic by-products.

NITRATE AND BEETROOT JUICE


Research shows that beetroot juice can improve endurance performance and
reduce the oxygen cost of submaximal exercise, as well as enhancing repeated
sprint performance. Studies suggest 300–600mg nitrate, equivalent to one or
two 70ml beetroot ‘shots’, taken two to three hours before exercise, is the optimal amount.
Results have been more compelling in untrained subjects, so if you’re fit already, don’t
count on huge gains.

CAFFEINE


Low to moderate (1–3mg/kg bodyweight) caffeine doses improve alertness,
concentration and reaction time. There’s good evidence it enhances
performance in both high- and low-intensity exercise and reduces the perception of effort
during endurance exercise. Levels peak at around 30–45 minutes after consumption.

WHEY PROTEIN


Whey contains a high concentration of essential amino acids, which support
muscle recovery, including the amino acid leucine, an important trigger for
stimulating muscle building after exercise. Choose whey supplements if you aren’t getting
enough protein from your diet (in most cases unlikely) or as a convenient post-workout
alternative to food.

FE


44 | February 8, 2018 | Cycling Weekly

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