Look, you should really be exercising more than once a week. Work it into your everyday life, if you have to (climbing stairs, parking far to walk, carrying heavy stuff, etc). However, if you absolutely can’t make the time, or if you just want to supplement your yoga, sport, or what have you, this routine will help you get the most bang for your buck. Go out, buy one of those cheapo weight sets, and get ready to lift.
If you have a limited time frame, sprints are more effective at burning fat than steady-state running and improving cardiovascular endurance. Go all out and do some walking to recover before hitting your next sprint. If you’re just starting out, it’s not a bad idea to do a slower, steady run to get a base down, though. Then if you have the extra time, nothing quite replaces true endurance building, but sprints work great on a consistent basis.
Some good routines are 10-12 x 100m (about a football field in length) and 4-5 x 400m (about a quarter mile).
“The king (or queen) of exercises” truly earns its name. No other exercise can match the amount of muscles this move recruits or relative safety (just don’t round your back). No spotter? Just drop the weight. Olympic lifts may use more muscles, but they also take a bit more time to master the movement. Plus, the deadlift is generally the heaviest lift, which is really mentally satisfying.
If a deadlift is the ruler of the land, the squat is its partner. Squatting is a great functional exercise that can give you a boost in almost every area of your life. It burns a ton of calories, to boot.
If you sit at a desk all day, you need to be doing hip thrusters, end of discussion. They work your glutes and hamstrings that get atrophied from constant sitting and help offset pelvic imbalances.
The bench press is great, don’t get me wrong, but if you want the best upper body exercise, this is it. It uses more muscles (especially standing) and is safer without a spotter. That said, you won’t get a ton of chest development from it (besides the upper chest), but it’s a small price to pay for the timesaver this exercise is.