We report here the case of a 17-year-old boy who suffered acute renal failure after consuming 3 L of energy drink (ED) in combination with 1 L of vodka amounting to 4600 mg of taurine and 780 mg of caffeine mixed with 380 g of alcohol. The consumption of this mixture is extremely popular in adolescents, because the joint effects of caffeine and taurine reduce the effect of alcohol. Although there have been case reports of deaths linked to the consumption of EDs with and without alcohol, awareness of the possible dangers is still low. The fact that athletes and major sports events are sponsored by ED manufacturers implies that they may even be healthy and performance-enhancing.

Based on the wide range of problems to effectively perform cardiopulmonary testing in young children, this study strives to develop a new cardiopulmonary exercise test for children using a mobile testing device worn in a backpack in order to test children during their natural movement habits, namely, running outdoors. A standard cardiopulmonary exercise ramp test on a cycle ergometer was performed by a group of twenty 7–10-year-old children. The results were compared with a self-paced incremental running test performed using a mobile cardiopulmonary exercise measuring device in an outdoor park. The children were able to reach significantly higher values for most of the cardiopulmonary exercise variables during the outdoor test and higher. Whereas a plateau in $${\dot{\text{V}}\text{O}}_{{2}}$$V˙O2 was reached by 25% of the children during the outdoor test, only 75% were able to reach a reasonable VT2, let alone $${\dot{\text{V}}\text{O}}_{{{\text{2peak}}}}$$V˙O2peak , during the bicycle test. The heart rate at VT1, the O₂-pulse, and the OUES were comparable between both tests. OUES was also positively correlated with $${\dot{\text{V}}\text{O}}_{{{\text{2peak}}}}$$V˙O2peak in both tests. Testing children outdoors using a mobile cardiopulmonary exercise unit represents an alternative to standard exercise testing, but without the added problems of exercise equipment like treadmills or bicycles. It allows for individualized exercise testing with the aim of standardized testing durations instead of standardized testing protocols. The running speeds determined during the outdoor tests may then be used to develop age-adapted testing protocols for treadmill testing.

Purpose: Cardiopulmonary exercise testing (CPET) in preschoolers (4–6 years) represents a challenge. Most studies investigating CPET have been limited to older children (> 8 year). However, knowledge of the performance of small children is essential for evaluating their cardiorespiratory fitness. This study strives to compare a modified Bruce protocol with a new age-appropriate incremental CPET during natural movement running outdoors, using a mobile device. Methods: A group of 22 4–6-year-old healthy children was tested indoor on a treadmill (TM) using the modified Bruce protocol. The results were compared with a self-paced incremental running test, using a mobile CPET device in an outdoor park. The speeds were described as (1) slow walking, (2) slow running, (3) regular running, and (4) running with full speed as long as possible. Results: Mean exercise time outdoors (6,57 min) was significantly shorter than on the treadmill (11,20 min), $$\dot{V}{O}_{2peak}$$V ˙ O 2 p e a k (51.1 ml/min/kg vs. 40.1 ml/min/kg), RER (1.1 vs. 0.98) and important CPET parameters such as $$\dot{V}E$$V ˙ E _max, O₂pulse, heart rate and breath rate were significantly higher outdoors. The submaximal parameter OUES was comparable between both the tests. Conclusions: Testing very young children with a mobile device is a new alternative to treadmill testing. With a significantly shorter test duration, significantly higher values for almost all cardiopulmonary variables can be achieved without losing the ability to determine VT1 and VT2. It avoids common treadmill problems and allows for individualized exercise testing. The aim is to standardize exercise times with individual protocols instead of standardizing protocols with individual exercise times, allowing for better comparability.