This is can be true or false.
Depending upon the amount of time that you spend recovering you will still be able to maintain your strength and potentially your body composition. However a lot of that depends on your level of activity and most definitely your nutrition.
When it comes to injuries – your nutrition is going to be the utmost importance especially if it means that you will not be able to train for a while. Having an understanding that how you train has a correlation with how you eat in reference to your goals. In other words, the general idea that you have a higher training frequency you also need to have a higher amount of calories to supply the energy for the demands of the workload.
When you are on travel or vacation, the same principle applies. However, it depends on your level of activity or dedication to training when you are away. It is also important to note that when you are away on a vacation, you are also away from a lot of stresses that you must factor in into your training.