Introduction: Today's organizations are dynamic, requiring leaders to adapt to this environment. Executive coaching is one of the most popular interventions to support leaders' development, and yet gaps persist in understanding how structured coaching programs influence transformational leadership over time.
Purpose: The aim of the current study is to use a longitudinal and experimental study design to examine the effects of a coaching intervention on transformational leadership.
Methods: A longitudinal experimental design was used with 92 managers from Spanish organizations, who were randomly assigned to an experimental group (n=48) or a control group (n=44). The experimental group received weekly one-hour coaching sessions, while the control group received no coaching. Both groups completed the Multifactor Leadership Questionnaire (MLQ-5X) to assess their transformational leadership levels before and after the intervention. Repeated measured ANOVAs were used to measure the impact of the coaching intervention on managers' transformational leadership behaviour.
Results: The intervention increased Idealized Influence and Intellectual Stimulation levels, while the Inspirational Motivation and Individualized Consideration levels remained stable.
Conclusion: Short-term executive coaching enhances the cognitive dimensions of transformational leadership but is less effective in improving the emotional/relational dimensions. This study contributes to the literature supporting coaching as a leadership development tool and suggests combining it with other interventions for holistic improvement in transformational leadership.