Safety

Excessive caffeine intake has been linked with a number of health issues. Pure or highly concentrated caffeine can be potentially lethal and hence poses an acute risks to consumers. Death has been reported after a single dose of 3g of pure caffeine. As such, in 2019, the Therapeutic Goods Administration took steps to prevent the sale of pure-caffeine products within Australia. Other caffeine side-effects include increases in heart rate, impairments or alterations of fine motor control and technique, and anxiety or over-arousal.

In terms of caffeine within food products, various international health agencies consider caffeine to be a generally safe compound for to adults to consume, especially when low to moderate doses are ingested. These doses are commonly defined as

• ≤400 mg/day from all sources (except for pregnant individuals), and
• ≤200mg at any one time

The use of caffeine by children carries greater risk, and children <18 years are suggested to limit caffeine intake to <2.5 mg/kg/d.

We would advise that choosing caffeine from therapeutic sources such as No Doze is preferable over choosing caffeinated pre-workouts as these sports products can contain variable amounts of caffeine and also pose a risk of containing banned substances.

Sleep

Caffeine can affect sleep onset and quality, even at low levels of intake. This may interfere with the athlete’s ability to recover between training sessions, or multi-day competitions. Given the half-life of caffeine is ~5 hours (i.e. about half the drug remains in your blood after this period), consideration should be given to the timing of caffeine intake relative to the need for sleep.

Dehydration

Small to moderate doses of caffeine have minimal effects on urine losses or the overall hydration in people who are habitual caffeine users. In addition, caffeine-containing drinks such as tea, coffee and cola drinks provide a significant source of fluid in the everyday diets of many people.

Genetics

The effects of caffeine vary markedly between individuals. Each athlete should make decisions about caffeine use based on experience of their own responsiveness and reactions, including side-effects. It remains unclear whether genetic differences related to caffeine metabolism or adenosine receptor density explain the contrasting performance effects³.