Machines or free weights? First decide what the exercise needs to do. Practising a particular barbell lift and fitting a useful session into a hotel gym are different tasks, even when they involve similar muscles.

Research has not found a consistent muscle-growth winner between the two categories. Strength tests can favour the equipment used in training. That is a reason to match practice to the goal, not to dismiss either option.

Ask whether the setup fits you, whether you can repeat it, and whether you can progress appropriately. A familiar machine may answer those questions well. A free-weight exercise may be better for a specific skill.

Forty kilograms on one machine is not automatically equivalent to another machine or a dumbbell exercise. Record the station and settings. Establish a new baseline when the equipment changes instead of copying the number blindly.

A machine still needs correct adjustment. Free weights still need control and appropriate safety arrangements. Ask for instruction when the start, stop or safety features are unclear. Persistent pain needs assessment, not a category switch.

A programme can include both machines and free weights. Choose exercises you can perform and repeat consistently. The full guide includes a decision table for travel, skill practice and tracking progress in an unfamiliar gym.