Train for Reps
If you're over the age of 30, you may need to rethink the "go heavy or go home" mantra. Higher rep ranges have several benefits, and not just for building muscle.
A lot of coaches say that lifting weights for higher reps makes you more prone to injury. In the case of training methodologies that have you racing the clock, it's true. But sets of 10-12 or even 15 reps of a compound movement (squat, deadlift, overhead press, bench press, etc.) shouldn't be outside the vocabulary of a recreational lifter who has his health and wellness first in mind, along with building plenty of muscle and strength.
The positive factor no one seems to bring up is the fact that the weight needs to be significantly lighter to make this happen. That in itself can spare joints and connective tissue of plenty of stress, something you need to start thinking about if you're over 30 and have years of heavy lifting experience under your belt. And assuming adequate rest and good form, it's rare to see a lifter injure himself during a set of 10 reps at 75% of his max.
Real Life Requires Muscular Endurance
Using real life as our guide, the hard truth of the matter is this: We need strength a whole lot in our daily lives to make things easier, but most "life demands" that require strength also require muscular endurance. That's a truth that gets swept under the rug in favor of heavy triples.
We don't help someone move furniture or even carry all our groceries by picking them up for 3 seconds and putting them back down. In both cases, we're under tension for extended periods of time, and we'd be remiss to overlook that and avoid training for reps in the gym.
Plus, it's good for our heart too. If you avoid the higher rep ranges on big compound movements, is it because you gas out too quickly? That's a sign. Get in shape!