Yes, early evidence suggests that you can drink milk before cycling (specifically low-fat or fat-free milk) without incurring GI distress during a ride, provided you do not have a milk protein allergy or lactose intolerance. Milk provides carbohydrates to fuel working muscles during a ride, protein to support muscle growth, and increased fluid intake to prevent dehydration, all of which can help support performance[1
Milk is also a good source of calcium and Vitamin D, both of which play an integral role in bone health (which is important for athletic performance) [3
]. Since your body needs vitamin D to absorb calcium and ultimately strengthen bones, it’s important to look for dairy products that are fortified with one (or both) of these nutrients. However, if you have a dairy intolerance or allergy, you should avoid milk. Instead, choose a milk alternative that is also fortified with vitamin D and calcium.