For females this would usually be finished in about 1 hour 15minutes. For males this would be finished in about 1 hour. Olympic distance triathlon (1500m / 40m bike / 10km run) For females this would take about 2 hours 25mins. For males this would take about 2 hours. Half Ironman (1.9km swim / 90km bike / 21km run) Females usually take about 5 hours 30mins.
Zinc. Night blindness may also be the result of a zinc deficiency which reduces the activity of an enzyme that helps the body produce vitamin A (retinol dehydrogenase). Research has shown that taking a zinc supplement is helpful. Healthcare providers often recommend 15 - 30 mg of zinc daily for vision.
Diet & Nutrition. 1  Vitamin A is the most clearly researched deficiency associated with night blindness. 2  Zinc if you have a zinc deficiency, then zinc combined with vitamin A is more helpful than vitamin A alone.1. 3  See our recommendations for diet / lifestyle.  Vegetables.