## 2 Factors Affecting the IOP Response to Exercise
### Nutritional Ergogenic Aids  
Performance during sporting activities can be significantly influenced by well-chosen nutrition strategies. Adequate nutrition plays a vital role in supporting athletes' physical capacity, recovery, and overall performance. In recent years, dietary supplements have become increasingly popular as a convenient and practical alternative to help athletes meet their nutritional needs, especially when certain nutrients or compounds may be challenging to obtain through food alone [81; 82]. However, it is important to note that not all supplements are without risks. Some have been associated with harmful health effects, ranging from minor issues like gastrointestinal discomfort to more serious adverse events affecting various organ systems. These adverse effects can occur across all age groups,from amateur athletes to elite competitors, underscoring the need for careful consideration when incorporating supplements into an athlete's regimen [83]. For glaucoma patients, certain nutrients have demonstrated benefits, such as lowering IOP or improving optic nerve blood flow [9; 11]. In fact, nutritional supplementation can serve as a complementary strategy for managing glaucoma and other eye conditions; however, it is also essential to acknowledge that some supplements may have undesirable effects and should be prescribed by qualified professionals. Among the most popular and extensively studied dietary supplements is caffeine, widely recognized for its potential to enhance both physical and cognitive performance. Caffe is known to stimulate the central nervous system, leading to increased alertness, reduced fatigue, and improved focus, all of which are beneficial during exercise and competition [84]. Given these performance-enhancing effects, caffeine has been incorporated into various pre-exercise and during-exercise supplementation strategies. The effects of caffeine on IOP have been widely studied in non-sport contexts, with research focusing on its impact on IOP in both healthy individuals and those with conditions like glaucoma [8; 9; 85; 86]. In the context of exercise, however, there is a relative paucity of research exploring how caffeine influences IOP during physical activity. One study, for instance, examined the impact of caffeine intake (-4 mg/kg) on IOP responses during low-intensity endurance exercise, specifically 30 min of cycling. The study found that caffeine intake appeared to counteract the IOP-lowering effects typically observed during low-intensity exercise. While exercise can generally reduce IOP by enhancing ocular perfusion and reducing systemic vascular resistance, caffeine seems to reverse this effect in the short term, leading to an increase in IOP during physical activity [85]. This suggests that caffeine ingestion may disrupt the typical IOP reduction that is often seen with endurance exercise. In the short term, this indicates a potential negative effect on IOP stabilization, particularly for individuals who are susceptible to elevated IOP or those with glaucoma. Despite these short-term effects, the long-term impact of caffeine consumption on IOP is less clear. Evidence from studies on chronic caffeine consumption suggests that regular intake may lead to a modest increase in baseline IOP levels. However, this increase in IOP is generally not associated with an increased risk of developing glaucoma, especially in individuals without a predisposition to the disease [87]. Some studies suggest that, over time, the body may adapt to regular caffeine intake, potentially mitigating its acute impact on IOP [9]. Furthermore, animal models of glaucoma have provided some surprising insights into the potential neuroprotective effects of caffeine. Research has shown that caffeine may reduce neuroinflammation and protect retinal ganglion cells from degeneration, both of which are key factors in glaucoma progression [88].