Only having 30 minutes to train shouldn't be an excuse for skipping workouts. Half an hour is ample time to get your warmup, weightlifting and cool down in, leaving you free to enjoy the rest of your day. Shortening your weight workouts doesn't mean going easy though – if anything, a 30-minute session can be more taxing than a longer one, as you'll have to cut down rest time and work at a higher intensity to get everything done.
Weight Training – The Right Way
When the clock's ticking, the pressure is on to get the most out of every minute of your session. This means the exercises you choose are vital. Pick workouts that hit lots of different muscle groups at once and consider how much you're benefitting from certain exercises. When picking a move for your biceps, for example, you could either do biceps curls, which aren't particularly demanding and only work your biceps, or go for chin-ups, which hit your biceps, forearms, lats and rhomboids and are highly challenging. The same goes for other exercises too, so base your workouts around compound moves like squats, lunges, presses, rows and deadlifts.
The Superset Solution
You do need some rest in your session to give your muscles time to recover, but you needn't rest between every exercise. A superset involves performing two exercises back-to-back without a break. The three main types of superset, according to strength coach Tom Venuto, are same muscle supersets, where you perform two exercises for the same area, antagonistic supersets, where you pair opposing muscle groups, such as biceps and triceps, or chest and back, and non-competing supersets, where you work two completely different muscles such as shoulders and legs. Take this a step further by adding a third exercise to make a tri-set, or a fourth exercise to make a giant set, advises trainer Greg Merritt.
Don't Ask for Injury
You can't just go straight into your heavier, tougher sets as soon as you hit the gym floor -- that's asking for injury. Instead, spend just a few minutes getting warm with some dynamic movements similar to the exercises you'll perform in the session. A quick circuit of body weight squats, lunges and pushups works well. Coaches Joe Wuebben and Jimmy Pena of Muscle and Fitness recommend performing one to two lighter sets before each exercise too. So if you're going to be squatting with 155 lbs. for your main sets, perform a set of 10 at 75 lbs. and another at 115 lbs. first. At the end of your session, stretch each muscle that you've worked for 15 to 20 seconds each.
A Split Decision
The big question is whether to train your whole body in each session, or to just work one or two body parts. The full-body option works well if you're looking for more of a muscular endurance or cardiovascular-type workout, as whole body supersets and circuits are highly demanding, especially when you're trying to work everything in just 30 minutes. If bodybuilding and getting stronger is more your style though, split your body into three or four different sessions, such as a chest, shoulders and triceps workout, a legs workout and a back and biceps workout and perform each once a week.