Should I Promote My Gym or My Supplement Store Online? Need Advice

[Amara Kazaame]

Hi everyone,
I would like to ask that I already have my own gym, and I thought to start my supplements online store through digital marketing and sell my supplements online. But my friend suggested me to promote my gym online either than supplements as like on social media platforms like Youtube, Instagram, Tik tok etc.. So what should I do now? I'm confused. Kindly suggest to me what should be good to promote online.

Thanks in advance.