Not true! There’s the indirect mechanism you might be referring to when you say “both can be used for energy”: adipose tissue releases triglycerides, liver extracts glucose from triglycerides, muscle tissue stores glucose as glycogen. And there is also a direct mechanism - adipose tissue releases triglycerides which are directly stored in muscle tissue. This intramyocellular triglyceride is concentrated in skeletal muscle tissue and plays a significant role in endurance exertion (https://pubmed.ncbi.nlm.nih.gov/14987125/).