One of the most misunderstood and misused tools in the fat loss arsenal is cardio. When most people attempt to lose weight and get leaner, their first step is always adding in additional cardio or increasing the amount they currently do. In order to lose weight, we need to be in a caloric deficit. This means, taking in less energy than we put out. Cardio increases the energy out part of this equation, but the bulk of the caloric deficit should be achieved primarily by a reduction in total calories consumed. It is very difficult to achieve a reasonable caloric deficit by just doing cardio. You can't out-train a poor diet. Cardio should ONLY supplement the deficit you achieve through your diet. 

How Do I Implement Cardio?

  Once your caloric deficit has been established, it can been achieved with a combination of both diet intervention and added cardiovascular activity. In most cases, the majority of your progress can be attained by just creating a caloric deficit via reduction of total calories consumed, as there have been plenty of people who have got exceptionally lean without doing one minute of cardio. When dieting, we want to get away with eating as much food and doing as little cardio as possible. We want the minimal effective dose of both. This is crucial for muscle maintenance/gain. If you could lose weight at an appropriate rate on 2,000 calories, why drop to 1,000? The same can be said for cardio. If you could lose weight at your target rate doing only two 20 minute sessions per week of LISS (Low Intensity Steady State) cardio, why do 6 hour long sessions?

In order to decide how much cardio we should do, we will want to quantify our cardio somehow. This is typically done via calories burned per session or time spent. As advised by bodybuilding coach and researcher, Dr. Eric Helms, he does not suggest going over 1/3 of your time spent weight training doing cardio. For example, if you work out 5 days/week for about an hour, he would not suggest doing more than about a 1.5 hours of cardio per week. When starting out a diet, I would recommend not changing the amount you are currently doing. If weight loss stalls, you have the option to increase cardio by about 10% of what you are currently doing, or lowering your caloric intake by 5-10%. The slightest change, by either increasing cardio or lowering calories, can get you right back on track. 

What type of cardio should I be doing?

  There are many cardio modalities out there. My recommendation is that if you choose one, I would stick to it for at least a few weeks. If you do not have a device to count your calories burned per session, in order to keep things consistent, I suggest using the same machine each time and recording the calories burned on the machine. That way you can keep track of how many calories you are burning. Since the reading on the machine won't be 100% accurate, using the same one will give you a consistent metric to compare against. The same can be said for cardio classes. 

When choosing what type and when to do cardio, think about how it will impact your resistance training. For example, I do not suggest going on a 100 mile bike ride the day before a big leg day. With that said, I suggest doing your cardio either 8+ hours away from training. If that is not possible, you should do your cardio after your resistance training. Cardio does tap into your ability to recover, so be sure to take that into account when deciding what and when you do it. 

Take Home

  Is cardio needed to see results? No! You can achieve most of your physique goals without doing one minute of cardio. Cardio serves to facilitate a larger caloric deficit, but this deficit should be achieved primarily through diet. Do as little cardio as possible while still making progress. In many cases, cardio won't need to be added to see progress.

Finally, no you can't just burn off all the beer and wings you had on Saturday by hopping on the treadmill for an hour!