If you haven't gotten the memo yet, you need to be doing cardio. After cleaning up your diet and getting sufficient sleep it is one of the most important things you should be doing to stay healthy and fit.

How much do you need? The American College of Sports Medicine says at least 150 minutes/week and most folks need a mix of moderate and vigorous intensity.

But I get it. You're busy. So what form of cardio will give you the biggest bang for your buck? The treadmill is the most obvious choice, and while I am a big fan of running, for many folks the “dread mill” is boring and the impact hurts their joints. An elliptical machine is fine too, but if you've been using it exclusively for months or even years, you may have plateaued and could benefit from a new modality that will help you burn more calories and build more functional core and back strength.

Lately I've seen an uptick in the number of folks ditching their standard cardio routines and venturing over to the rower. Maybe we have House of Cards to thank for that. Whatever the inspiration, rowing can be an incredibly effective exercise. When done properly it is a metabolic, total body workout that strengthens a lot of areas the average desk-bound lawyer needs to work on (hip extension for the glutes and hamstrings, core stability for the trunk and of course mid back and arms from all that pulling). But without proper form you may find your lower back, hips and neck hurting.

Here is a simple video that demonstrates proper form. Don't think your stroke looks like this? Don't worry. Most folks need a little tweaking, particularly to fine-tune the level of effort between the lower and upper body and the timing of the leg, trunk and arm segments. Below I address three of the most common issues I see with clients when rowing and the most effective fixes.

How NOT to Row: All Arms, No Legs - Most folks use way too much upper body and not enough lower body. The fix? Roughly 60% of power should come from pushing with the legs, 20% bracing of the core and 20% from pulling with the arms.

How NOT to Row: Hunching Your Back - It's very important to maintain tension in your back muscles and not to round your back and shoulders. The fix? Sit with a tall, stacked posture relaxing your shoulders so they are pulled back and down. Spine should always remain neutral.

How NOT to Row: Legs First - Extending your legs too quickly will disrupt the rhythm with your pull. The fix? Focus on keeping your arms straight through your pull until the recovery (or “lean back”) phase after the oar pass past your knees.

If you're new to the rower, start out with just 5-10 minutes at a steady state moderate pace. It's more important and beneficial to spend less time with better form than more time with poor form. Slowly add more minutes to your workout as you become stronger and then begin to mix up your intensity and add some higher intensity intervals (short 30-second sprints followed by 30 to 60 seconds of recovery).

Jonathan Jordan is a personal trainer, nutrition coach and corporate wellness consultant in San Francisco. Check out his blog JJ Fit 24/7.