If you're thinking about lifting on your lunch hour, let me offer what I consider to be two underrated benefits of lunchtime workouts. First, exercise has been shown to increase cognitive performance and energy, which can help during those long workdays.[1] Second, less time to complete your workout means you'll be less likely to drag it out, which can result in a more intense session.

But, unless you're the boss of the boss, you probably have a rather limited amount of time to change, warm up, complete your workout, shower, and change back into your work clothes before someone notices you've been gone too long. I may not be able to help you change faster, but I can show you how to distill a full-throttled muscle-building routine into a lean, mean 45-minute session.

The Lunchtime Workout Plan

While you'll have to back off training volume to some degree—it's simply not possible to get 75-90 minutes of effort crammed into 45—the workouts here compensate by increasing training frequency. So, you'll do each body part twice a week, not once. That also provides a welcome change of stimulus, especially if you've been following a high-volume, once-a-week body-part split for a while.

Remember, when designing a training program, three critical variables can be manipulated either up or down:

• Duration, which relates to the length of your workout
• Frequency, which is how often you train a body part
• Intensity, or how hard you train, especially relative to your one-rep max

With this lunchtime workout plan, you'll be backing off on the overall duration but increasing frequency and intensity. (It would be counterproductive, by the way, to increase all three variables at the same time.)

One other critical point is to stick to multijoint exercises (especially with free weights over machines) as much as possible, because they engage a larger degree of muscle mass, allowing you to train multiple muscle groups simultaneously.

Workout Nuts and Bolts

Days 1 and 2: The first two workouts cover multiple body parts each day. Since the chest, shoulders, and triceps work together relatively synergistically, this is a great split to follow with a short time frame. Likewise, biceps and back are often trained together; in this split, they're paired with legs.

The workouts effectively utilize intensity boosters like dropsets, which allow you to train past initial muscle failure. To do a dropset, select a weight at which you can reach the target rep listed, then immediately reduce the poundage by about 30 percent and go to a point of muscle failure again. The workout plan also includes supersets, in which you pair two exercises back to back without resting between them.

Both techniques allow you to do more work in less time (allowing for greater volume) and are effective methods for building muscle in a hurry. Moreover, you'll get a bit of a cardiovascular boost as well, because your work-to-rest ratio will be higher than it normally would.

Day 3: While only one day this week has been denoted as a cardio lunchtime workout, that doesn't mean you should only do one day of cardio per week. You can't make improvements when you train just once a week, whether it's cardio or weights. Strive to do 3-4 sessions a week, two of which should be high-interval intensity training (HIIT), and the others steady-state.

After a warm-up, perform HIIT cardio, which alternates periods of all-out cardio (30-60 seconds depending on your ability) with much slower recovery intervals (60-90 seconds). I won't pretend to offer a one-size-fits-all HIIT workout, since HIIT needs to be dialed up or down depending on your ability level; however, your HIIT workout should be 20-25 minutes max, while the steady-state should be 30-40 minutes.

Include some core work as well, to strengthen your abs and lower back, a protocol you might also want to repeat on one of the weekend days with your cardio, or before or after work. You can substitute other movements should these prove too easy.

Days 4 and 5: On these days, the structure is geared more toward strength, and you'll target that by selecting heavier weights for lower reps. Adding a strength-oriented intensity-boosting technique like rest-pause effectively allows you to get more heavy-weight work done in a limited time period. You'll still do some dropsets and supersets to save time.

Rest-pause is a proven strength builder.[2] Here, it's done with two different rep targets—10 and 12. When you use your 6RM weight—that is, a weight you can lift cleanly for 6 and only 6 reps—do your initial segment for 5 reps (a rep shy of muscle failure). Quickly rack the weight and rest for 20 seconds before continuing the set. Aim to get 3-4 more reps, rest again for 20 seconds, and do the final segment for as many reps as you can.

With this method, you might complete 11-12 reps in one set (consisting of three segments) using a weight you can only do for 6 in one shot! When rest-pause is instead done with your 8RM (the weight will be slightly lighter), do the first segment for 6 reps, then 3-5 on the second one, and as many as possible on the last.

Max Muscle Lunchtime Workouts

Do as many warm-ups as you need. Choose a weight so that you reach muscle failure by the target rep listed.

References

1. Hogan, C. L., Mata, J., & Carstensen, L. L. (2013). Exercise holds immediate benefits for affect and cognition in younger and older adults. Psychology and Aging, 28(2), 587.
2. Orchard, J., Wood, T., Seward, H., & Broad, A. (1998). Comparison of injuries in elite senior and junior Australian football. Journal of Science and Medicine in Sport, 1(2), 83-88.