There are lots of drinking beet juice benefits before workout:

Numerous studies suggest improved exercise stamina and that naturally occurring nitrates present in beetroot can enhance physical performance during high-intensity endurance exercise. Also, dietary nitrates have been shown to reduce oxygen use during physical activity. Thus, it may improve cycling and running performance, boost oxygen use, and improve overall exercise performance.

Improves muscle power in people with heart failure: sending signals to the tiny muscle cells around your arteries and telling them to relax, which is excellent after exercise.

It helps you maintain a healthy weight: since they are high in water and low in calories. Beets also contain moderate amounts of protein and fiber. These are both critical nutrients for achieving and maintaining a healthy weight.

May slow the progression of dementia: beet improves blood flow to the brain's frontal lobe, which is associated with higher-level thinking, such as decision-making and working memory.

It may reduce cancer risk: The antioxidant content and anti-inflammatory nature of raw beets have led to an interest in their ability to prevent cancer. Evidence suggests that chronic inflammation is a precursor of cancer; thus, we should always aim to reduce inflammation in our bodies. Beets fight inflammation in our bodies.
Aids reduce cholesterol. By breaking down the bile acid in your liver, beet juice can help regulate cholesterol levels.

Help reduce cardiovascular risk. Beet juice contains a unique blend of phytochemicals and antioxidants that may benefit overall heart health by reducing blood pressure and protecting LDL from oxidation.
Supports your liver: the antioxidant betaine potentially helps prevent or reduce fatty deposits in the liver produced by a condition called nonalcoholic fatty liver disease.

Excellent source of other essential minerals: manganese, potassium, and the super important iron, to prevent anemia.
Drinking beet juice may represent a good source of folate important for normal cell function and tissue growth.

Lower Blood Pressure: High blood pressure can damage your blood vessels and heart. What's more, it is among the most decisive risk factors for heart disease, stroke, and premature death worldwide. Drinking beet juice may help lower blood pressure levels, as it relaxes blood vessels, improves blood flow, and aid in cardiovascular disease.