If you’re a busy adult looking for a maximal return of fat loss, weight loss, strength and overall performance with a minimal time investment, here are some simple exercise switches you can make to pump up your exercise portfolio and get awesome results.

Poor Investment: “Crunching” Exercises

Despite “feeling the burn,” crunching exercises do very little in terms of burning calories and fat. While they can improve the strength and muscle tone of the rectus abdominis (the main “6-pack” muscle), crunching exercises do very little to shrink the layer of fat that sits over it. To see the abdominal muscles, specific dietary and other resistance/cardiovascular exercise interventions must be strictly followed to significantly shrink this layer of fat.

Additionally, the crunching motion replicates the “hunched” position of sitting that has been found to be the culprit of many adults’ lower-back pain.

Better Investment: Proper Diet and Planks

“Six-pack abs” are created in the kitchen, not the gym. You simply can’t outwork a bad diet. A better approach is to eat light and eat often, significantly limit sugar and processed food, and pack your plate greens and lean proteins. This decreases the likelihood that fat will be stored and increases the likelihood that it will be burned. Less fat, more abs.

For specific abdominal strength, the plank is a better alternative for strengthening the abs and integrating the “core” muscles. While in a plank, you are actually integrating muscles throughout the entire body to create an isometric contraction. Other exercises, such as chops and carries, can also help strengthen the trunk muscles without harming the lower back. A few sets of 30-60 seconds every workout should suffice.

Poor Investment: Single-joint Exercises

Single-joint exercises isolate movement to a single joint and muscle through specific postures or mechanical devices. Examples include biceps curls, triceps extensions, crunches, shoulder raises and leg extensions.

While there is nothing inherently “wrong” with these exercises, the small amount of muscle that is targeted limits the physiological disturbance required for fat loss. Spending a majority of limited workout time and energy performing these exercises is a poor investment if your goals include fat loss, muscle gain and overall performance.

Better Investment: Multiple-joint “Compound” Exercises

Compound exercises, such as deadlifts, squats, push-ups, lunges and pull-ups, integrate the movement of multiple joints and major muscle groups. Due to the amount of muscle used, these exercises create physiological chaos, resulting in a greater potential for muscles to grow and fat to shrink.

Poor Investment: Excessive Rest Between Sets

Depending on the goals of a workout program, extended rest periods between sets may be critical for maximizing performance. However, when time is limited and program goals are outside of maximal strength and power, resting for more than 60 seconds between sets is usually unnecessary.

If you are able to continue with an exercise after a rest of less than 30 seconds, make the exercise more difficult. However, extended time between sets spent staring in the mirror, looking at your phone or socializing with your workout buddies hinders your ability to recoup a maximal return on your investment of workout time.

Better Investment: Supersets

Supersets are exercises focusing on opposing muscle groups that are performed in succession with little-to-no rest in between. For example, you would do a set of 10 push-ups (for the chest and shoulder muscles) and then immediately go into a set of pull-ups (for the back and bicep muscles). Supersets are an extremely efficient way to incorporate many different fat-burning, muscle-building exercises into a short period of time.

Performing back-to-back compound exercises stokes the physiological fires for muscle building and fat loss. The fact that they are opposing one another means that one muscle group has a chance to recover somewhat while the other is working. In this case, exercise intensity can remain fairly high.

Poor Investment: Prolonged Low-intensity Cardiovascular Exercise

It’s difficult to call any form of aerobic training a poor investment of time. However, when maximum results in minimum time is the goal, slowly trudging along on an elliptical or treadmill for an hour at a low heart rate falls short of optimal.

During low-to-moderate intensity cardiovascular exercise, you typically exercise at a heart rate between 50-70% of your heart rate max. While there are quite a few benefits to this type of exercise, particularly for endurance athletes, beginning exercisers and those with certain physiological conditions, a lot of exercise time is recommended to see results (usually 30-60 or more minutes). Additionally, the more you train at these intensities, the more time that is required to continue to reap benefits.

Better Investment: High-intensity Cardiovascular Interval Training

High-intensity cardiovascular interval training utilizes bouts of high-intensity exercise followed a bout of low-intensity recovery. For example, running as fast as possible for 1 minute, then walking for one minute, and repeating this cycle for the desired amount of time.

Both high- and low-intensity cardiovascular training play a role in overall fitness. However, it appears that high-intensity training (generally resulting in a heart rate above 80% of maximum) can get more “work” done in less time. The high-intensity bouts bully the body’s physiology into creating changes to the cell, the muscle and metabolism in less time than with steady-state, low-to-moderate intensity training.

Use these exercise switches to optimize your workout time investment portfolio. Spend your valuable resources of time on exercises and programs that give you the fastest, safest, most significant results.

Learn more about common gym mistakes here.