Historically fitness testing has been identified as a common but controversial physical education (PE)-for-health practice across the globe. Despite this, little is known about the current prevalence and implementation of fitness testing. This paper therefore reports on findings from a survey which gathered both quantitative and qualitative data to explore the 'if?', 'why?' and 'how?' of fitness testing and provide new insights into teachers' learning intentions, pedagogical practices, and attitudes towards it. The survey was distributed to PE departments in secondary schools across the UK, and responses were analysed and reported descriptively and thematically. Responses from 260 schools highlighted that fitness testing remains a common practice in PE, with 80% of PE teachers reporting it to feature in their curriculum. There was less consensus surrounding the 'why?' and 'how?' of testing, with variation evident in teachers' stated learning intentions, pedagogical practices, and attitudes. Despite its prevalence, PE teachers expressed concerns over negative pupil outcomes potentially arising from fitness testing, and over 60% of teachers were uncertain or agreed that fitness testing can have a negative impact on pupils' psychological health. Given the findings and the reported widespread prevalence of fitness testing, further research should explore pupils' perspectives, responses, and outcomes of fitness testing, including their motivational and emotional responses to testing. Working with teachers and encouraging them to critically reflect on the 'if?', 'why?' and 'how?' of fitness testing is recommended and will hopefully help to bridge the gap between research and practice.