resistance training and / or aerobic exercise...what do they do to middle age muscle?

Phillips lab at  McMaster university churns these studies out!

Concurrent resistance and aerobic exercise stimulates both myofibrillar and mitochondrial protein synthesis in sedentary middle-aged men

Here they look at the impact of :

• resistance training alone;
• aerobic exercise alone; and
• resistance exercise and aerobic exercise together;

in sedentary middle-aged men.  (I'm 44.  Am I middle aged yet?)

The way that I read it is that doing both together is equivalent in effect  - in most measures they were looking at, protein synthesis in the muscles mainly) to doing either resistance exercise or aerobic exercise.

Questions for discussion....

• Why was the resistance exercise 8 sets of 8 reps?  Why not something simpler?
• What is more time efficient?
• Why do they always pick leg extensions?