This chapter aims to tackle the topic of physiological balance for sport and exercise through the lens of the neuroendocrine (nervous and hormonal) systems. All of the body systems reviewed in Section 1 of this textbook are subject to imbalance during prolonged periods of training load and stress, but the neuroendocrine systems represent quite an obvious barometer of change, that can be clearly addressed via dietary, mental-emotional, lifestyle and exercise interventions. Physiologically, a lot of insight into these systems can be gained by understanding and assessing the hypothalamus-pituitary (HP) axes and their target glands, including the adrenals, thyroid, and gonads, plus associated nervous system functioning. Additionally, research interests into allostasis and hormesis provide us with an extra layer of awareness of how an athlete’s life, or ‘ecosystem’, can impact on these physiological systems, both positively and negatively. Nourishing and restoring imbalances that may have occurred are vitally important to enable an athlete to achieve optimal health alongside sporting fulfilment. Interventions can include recuperative activities between training sessions, adjustment of training load, and the employment of nutritional strategies that are replete with macro and micronutrient density, including carefully targeted supplementation.