What does Warwick Schiller mean by emotional fitness in horses?

Emotional fitness is the concept that Warwick Schiller has developed as a primary framework for understanding what horses need from their training and human relationships — the idea that a horse's ability to regulate its own emotional state, to return to calm after stress, and to remain in a learning-capable state rather than a survival-reactive state is the foundation on which all effective training rests. A horse that is emotionally fit, in Schiller's framework, has developed the nervous system resilience to experience mild stress without tipping into a full arousal response, to recover from arousal quickly and completely when the stressor passes, and to remain in the present-moment engaged state where learning is possible rather than being chronically activated by anxiety, hypervigilance, or shutdown. The concept differs from the conventional natural horsemanship emphasis on desensitization in an important way: desensitization focuses on reducing the horse's response to specific stimuli through habituation, while emotional fitness development focuses on building the horse's overall nervous system resilience so that its capacity to regulate itself in response to any stressor is improved. Schiller's approach to developing emotional fitness includes specific practices — allowing the horse to process experiences at its own pace rather than pushing through resistance, recognizing and respecting shutdown as a genuine stress response rather than compliance, developing the horse's ability to seek and accept connection with the human as a source of safety — that differ significantly from the exercise-based desensitization approaches of more conventional natural horsemanship programs. The emotional fitness framework has resonated with many practitioners because it provides language for the quality of some horses that conventional natural horsemanship work seemed unable to reach — horses that were compliant under training but anxious, disconnected, or chronically reactive in ways that indicated unresolved emotional distress rather than training problems.