I think the concepts behind the diagram below are largely self-evident, but the primary message is that by adopting a confident, relaxed and comfortable posture and attitude you enhance your ability to deal with pressure. On the other hand, passively holding an unconfident, tense and awkward posture can lead to less than optimal results.
These postures or attitudes are affected by external stimuli such as praise or criticism of performance, and so performance management in organisations is highly relevant. However, self-awareness of your own posture/attitude can help you adopt a posture that is more positive and resilient regardless of external input.
Testosterone and cortisone are the chemical-biological intermediaries which are generated in response to pressure, converting pressure into either increased performance via the confident-relaxed-comfortable posture or into increased stress via the unconfident-tense-awkward posture.