Background: Aerobic fitness is of great value for reducing risk of mortality and cardiovascular diseases. Objective: This study evaluated the performance in and correlations between a new test (five-minute pyramid test, 5MPT), the six-minute walk-test (6MWT) and maximal oxygen uptake (VO(2max)) among old and young adults. Methods: Forty-four habitually active adults (females and males), 23 old (64-79 years) and 21 young (20-32 years) participated. In the 5MPT, the participants moved back and forth along a short walkway (5.5 m) over boxes (height: 'old people' 0.42 m, 'young people' 0.62 m) arranged like an elongated step pyramid for 5 min. Power in the pyramid test (5MPT(power)) was calculated as the product of numbers of laps, body weight, gravity and highest box level divided by time. A 6MWT and a maximal cycle ergometer test for direct measurements of VO(2max) were also performed. In all tests heart rate, with on-line electrocardiography, and perceived exertion were recorded. Results: There was a strong correlation between the 5MPT(power) and VO(2max) for the entire group studied (r = 0.98), and each of the four subgroups old and young females and males separately (r = 0.78-0.98). Contrary to several earlier studies, especially involving people with various diseases, the present data showed that 6MWT cannot be used to predict VO(2max) among old females and young adults. The correlation with VO(2max) was weaker for the 6MWT than for the 5MPT(power). The relative performance values for the old compared to the young (ratio old/young × 100) were considerably lower in 5MPT(power) and VO(2max) (47-55%) than in distance and 'work' in the 6MWT (82-86%). Conclusions: The results, with age and gender variations, can be valuable information in health-fitness contexts, since measuring physical aerobic capacity is very significant in connection with risk evaluations of mortality and various diseases. The 5MPT is a rapid, functional, easy and inexpensive tool for predicting assessed maximal aerobic power.