Background The theory of challenge and threat states in athletes (TCTSA) proposes psychological antecedents will predict psychological and cardiovascular responses to stress. The present study investigated this theory in two contextually different stress tasks. Method 78 males completed a computerised competition and a public speaking task. Cardiovascular activity was measured with impedance cardiography and a blood pressure monitor. Challenge and threat antecedents, indicators of challenge and threat and emotions were assessed pre- and post-tasks. Results Both tasks induced significant perturbations in cardiovascular activity and were perceived as highly challenging. Reported perceived threat was higher in the public speaking task compared to the competition task. Associations between the proposed antecedents, self-report and cardiovascular indices of challenge and threat and emotions support the TCTSA for the competition task, but less so for the public speaking task. Conclusion The TCTSA is supported during competitive stress, however during social stress there is dissociation between self-report appraisals and cardiovascular reactivity.