Workout routine for beginner

Hey guys,

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I'm an 18-year-old male, 5'9", and naturally skinny. I have a pretty fast metabolism, so gaining weight has always been difficult for me.

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I started going to the gym about 2 months ago with my cousin. My cousin and the trainer usually tell me what exercises to do, and I've been following their routine. So far, I haven't noticed many results except that my biceps look a little bigger.

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Recently, I asked an online friend who has a really good physique for advice. He told me that since I'm a beginner, I shouldn't be following the routine my cousin and trainer gave me. Instead, he suggested a different plan where I train 2 muscle groups per day, doing 3 exercises for each muscle group.

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The routine my cousin and trainer have me doing is completely different. They make me train only 1 muscle group per day, but with 6–7 exercises and a much heavier workout overall.

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So now I'm confused. As a beginner, which approach should I follow? The 2-muscle-groups-per-day routine from my friend, or the 1-muscle-group-per-day routine from my cousin and trainer?

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Any advice would be appreciated.

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