Best thing you'll ever do for functional strength/endurance - kettlbebells and polypropylene ship yard rope.
Been doing this for some time off and on. Just started doing a regimen off n' on, 4 days week, in lieu of my work schedule. One of the most efficient anaerobic/aerobic exercises with max heart putput. Just 4 sets of 30-60 seconds, with a minute rest between each set; you will be shaking your fist at the sky

It's very brutal when starting out, lots of sweat, lots of pain, but the benefits after your body recovers and when you start up your regimen next time - you'll be ready to go. Very very powerful. Imho, doing this for months on end, you'll develop outstanding cardio, excellent muscular endurance, and great functional strength.
A Beginner's Guide to Battle Ropes - Onnit Academy
^^ Heres an excellent site that explains much for beginners. It's what I had read religiously before i started.
I've also recently went consistent with kettlebells. I do 5 one-minute sets, first with a lighter weight like 30-35lb, then last set with a 45-50lb (higher weight geared towards muscle growth; ie: why i switch to a heavier weight last set/ slow twitch fibers) You can use just one KB and work each side, or use two and do each exercise while using both. I do double handed cleans and single leg/hip swings, double leg/hip swings.
Recommend to start with a lighter weight, like 15-20lbs. I know it might not seem like swinging around a 15lb kettlebell is that brutal, but trust me - looks are deceiving, and after your first set you'll be sweating profusely, whole body essentially aching =).
The thing with kettlbells is that they encompass a full range of motion; most exercises with them being based from a 'swinging' motion, starting from your legs, generating power/strength/endurance up through the hips, eventually exiting through the motions of your back/shoulders/arms/etc (sometimes a little chest). This is as functional as functional strength can get, ime. Also, kettlbebells/battle ropes are very safe for joints/etc, as they don't specifically isolate joints with prolonged strain like doing a barbell curl would or some other isolated/semi isolated movement. Plus, ropes/kb's are just much more fun/beneficial than lifting some barbells/dumbbells =)
You'll start to notice after the first couple times of doing both (or even just one of the 2 exercises) that everything in life becomes noticeably easier - everything from lifting a piece of food to walking, to breathing; any possible motion/function you do in your daily life. Your life becomes drastically easier - physically speaking.
And obviously, doing this as a set regimen will add years to your life; also drastically improving your mental well-being over time. Very powerful tools imo.
Any questions, feel free to ask. This stuff is my specialty
