The core drivers of muscle strength are resistance training + adequate protein + sleep. Nutritionally, the key is sufficient protein distributed across the day—not just a single large serving. Include quality protein at each meal (eggs, yogurt, fish, legumes, etc.) to support repair and adaptation. Severe energy restriction can impair muscle gain. Micronutrients like vitamin D and magnesium support function, but the primary stimulus is exercise. Resistance training (weights, bands, push-ups, squats) triggers muscle adaptation; 2–3 structured sessions per week is a strong baseline. Hydration and electrolyte balance influence cramps and performance. Muscle strength also protects bone health by reducing falls. If weakness is new, accompanied by major weight loss, or includes neurological signs, seek clinical evaluation.