The Steep Ramp Test for easy cardiorespiratory fitness assessment

To facilitate an easy assessment of cardiorespiratory fitness (CRF), the LIfelong Fitness Testing (LIFT) project aimed to develop a feasible toolkit for standardized Steep Ramp Test (SRT) assessment and interpretation in daily (clinical) practice and research. Partners in this public private partnership consisted of public partners with extensive experience in CRF assessment and a private partner with extensive expertise in marketing and development of medical devices. 

Although CRF is being recognized as an important marker of health and functioning, it is currently not routinely assessed in daily (clinical) practice. There is an urgent need for a simple and feasible exercise test that can validly and reliably estimate an individual’s CRF. The SRT is such a practical short-time exercise test on a cycle ergometer. Although the SRT is already frequently used in the Netherlands, norm values for adults and elderly were lacking, which limited interpretation of test results. Furthermore, health care professionals all developed their own routines in executing the SRT. 

The project objectives were therefore 1) collecting an adequate set of representative sex- and age-specific norm values for SRT performance in healthy adults, including elderly, 2) investigating the clinimetrics (criterion validity and test-retest reliability) of the SRT in this population, 3) examining the physiological responses during SRT performance, and 4) developing a feasible toolkit for standardized SRT assessment and interpretation. 

The development of age- and sex-specific Dutch norm values for SRT WRpeak in healthy adults aged 25-85 years is in the final phase, with over 600 participants included. The SRT demonstrated excellent test-retest reliability, as well as very high criterion validity and high construct validity for assessing CRF in healthy adults, including the elderly. Furthermore, SRT WRpeak showed a moderate-to-good positive correlation with maximal isometric quadriceps strength, and preliminary results suggest that the SRT is less cardiopulmonary demanding than CPET in this population. A practical toolkit has been developed to conduct the SRT in a standardized manner, enabling structured analysis and reporting of results, both at an individual level and relative to the norm values.