Trent is a 20-year-old college student and intercollegiate football player who works outs daily and wants that extra competitive edge. Trent tells his trainer he’s been experiencing headaches, insomnia, rapid heart rate, irritability, upset stomach and facial flushing. He wonders if energy drinks are causing his misery. The team trainer sends Trent to the dietitian, who asks him to complete a food record and to return the next day with a can of energy drink, all of his supplements and the completed food record.

Trent is drinking three 16-ounce cans of SuperXX energy drink daily. Each can contains 160 mg of caffeine and 200% of the Daily Value (DV) for niacin and B6, plus guarana, taurine, carnitine and 100 mg of ginseng. He takes two mega-multivitamins every day and uses a protein powder. His total niacin intake from supplements is 153 mg. Trent’s caffeine from energy drinks is 480 mg, but he buys a 16-ounce breakfast-blend coffee every morning; he doesn’t drink much water.

The dietitian surmises that Trent’s headaches, irritability and rapid heart rate are likely due to excessive caffeine intake from a combination of energy drinks and coffee. Guarana, ginseng and/or dehydration are probably contributing too. His excessive niacin intake is likely causing the facial flushing. High sugar content in the energy drinks and lack of water explain the stomach trouble.

The dietitian recommends an immediate appointment with the team doctor and suggests that Trent do the following:

  • Drink at least 8 glasses of water every day.
  • Take one multivitamin.
  • Find a protein powder with lower B vitamin levels.
  • Decrease his intake of energy drinks—gradually, to avoid caffeine withdrawal. The dietitian suggests decreasing consumption by one can a day every 2–3 days so that after a week, Trent is drinking just one can per day. Then he should switch to a smaller serving size.
  • Drink the energy drink within an hour before playing a sport and avoid consuming it close to bedtime.
  • Decrease morning coffee intake by buying a smaller size or by switching to a 16-ounce half-caf.

After 10 days, Trent reports that his headaches are gone, he’s sleeping better and his mood has improved. He still drinks one energy drink a day but does so within the hour before playing football. Trent sticks with water or a low-sugar sports drink most of the time.

It’s Not Just the Caffeine

Many are quick to blame caffeine for adverse reactions, but energy drinks are loaded with other ingredients that may trigger rapid heart rate, high blood pressure or heart palpitations when taken in excess (Higgins, Tuttle & Higgins 2010).

Guarana. The Brazilian cocoa seed contains guaranine, a caffeine equivalent that has not been evaluated by the FDA.

Sugar. Energy drinks contain 10%–12% sugar from glucose, sucrose or fructose. The combo of sugar and caffeine may boost athletic and cognitive performance, but this much sugar can cause gastrointestinal upset if consumed before sporting events. Diabetics should avoid high sugar concentrations (Campbell et al. 2013).

Taurine. A conditionally essential amino acid, taurine is abundant in food. Limited evidence suggests it may improve postexercise muscle repair (Higgins, Tuttle & Higgins 2010).

B6 and B12. B vitamins help with digestion and energy utilization. Energy drinks contain >100% of the Daily Value. One 5-hour Energy® shot contains >8,000% of the DV for B12 and 40 mg of B6 (>2,000% DV). Over 100 mg of B6 can trigger a rapid heart rate.

Niacin. Required for energy production, niacin may cause facial flushing and heart palpitations in adults consuming >150 mg. Many energy drinks contain over 200% of the DV. Children drinking energy beverages will exceed their Recommended Dietary Allowance and may develop flushing and rapid heartbeat more quickly.

Ginseng. This herb is touted as a means of improving athletic performance, mood and immunity. Therapeutic doses, 100–200 mg per day, may cause insomnia, rapid heart rate and hypertension (Higgins, Tuttle & Higgins 2010).

L-carnitine. An amino acid that participates in fat metabolism, L-carnitine may stimulate recovery from exercise stress (Higgins, Tuttle & Higgins 2010).

To learn more about consuming energy drinks check out the original article from the June 2013 issue of the IDEA Fitness Journal.