Supplements can influence fitness and health by helping individuals meet their nutritional needs, particularly when dietary intake may be insufficient. Common supplements include protein powders, vitamins, and minerals that support recovery, energy levels, and overall well-being. While they can be beneficial, it's essential to approach supplementation carefully, as excessive use can lead to adverse effects. Ideally, whole foods should serve as the primary source of nutrients, and supplements should complement a balanced diet. Consulting a healthcare professional before starting any supplementation regimen is advisable.