Guide to Timing Cardio Exercise

Among the most widely debated issues in the world of fitness is whether to work on cardio before or after weights, and whether the order of the two workouts even matters.

Although research does exist on the issue, it’s likely that even the most experienced personal trainers in your favorite gym would be split on which workout is ideal to start with.

To get to the bottom of this argument which has divided fitness enthusiasts for years, some of the advantages to both workouts, research on their affects, and other issues will be examined in depth.

Ultimately, an answer is provided and supported with numerous reasons why it’s better to do one type of workout before the other, with one possible caveat.

Brief Overview of Cardio Workouts

According to Verywell.com, cardio fitness is how well your body can sustain dynamic activity for a period of time. In the medical world, anything mentioning the word “cardio” pertains to the human heart, which makes sense when you consider that the heart is heavily involved in maintaining long periods of exercise.

This type of exercise is significantly different than strength workouts, and the athletes who excel at cardio do not require large amounts of strength to be successful. Doing cardio workouts frequently increases your endurance and stamina, two qualities that are necessary for many sports and activities.

Regular cardio workouts are officially recommended by doctors as part of a fit and healthy life, but whether it should be done before or after your strength workout is a highly-debated issue.

Four Primary Types of Cardio Training

Like everything in the fitness world, cardio has multiple variations, each with their distinct pros and cons. From the safe, casual low intensity workouts which are ideal for beginners, to more intense and advanced cardio workouts, each is designed to burn fat, but not all methods are equal.

Various factors determine the style of cardio people prefer, including the amount of time you have, the amount of intensity you prefer, and how prone to injury you are.

Whichever your choice, each method is guaranteed to add a strong fat burning element to your workout, and will provide all of the benefits that are known to come from a cardiovascular exercise.

#1- Low Intensity, High Duration

An example of low intensity training at a high duration would be going for a casual jog for an extended period of time. Generally defined as 40-60% of your max heart rate for a period of 40 or more minutes, this type of cardio is a decent way to burn fat, and is an ideal starting point for cardio workouts.

It should be mentioned that this is by far the easiest way to do cardio, and even obese and sedentary people will be able to maintain a low intensity cardio workout. To know if your workout surpasses low intensity, you can perform the “Talk Test”, meaning that you should be able to comfortably talk to someone while doing a low intensity cardio workout.

#2 – High Intensity, Low Duration

For those with limited time to get their cardio on, a high intensity cardio workout is a favorite of many busy people and personal trainers. Requiring only 5-20 minutes of your time, high intensity cardio involves consistent intense exercise with your heart pumping at about 85% of its max capacity.

Although it takes less time, high intensity cardio is shown to burn even more calories than a longer low intensity workout. The effectiveness of high intensity cardio is partially due to the fact that it burns calories for hours after your workout’s complete.

#3 – Aerobic Interval Training

An innovative and evolved form of cardio workouts, interval training implements both high and low intensity training at timed intervals in an attempt to reap the benefits of each method. Even MayoClinic touts the advantages of interval training, explaining that it not only spices up your workout, but can actually burn more calories than more simple forms of cardio as well.

There is nothing too complicated about interval training, as all you have to do is switch up your high intensity workouts with some low intensity versions, and vice versa. Some examples include adding a minute of full-speed sprinting into your casual bike ride, or jumping on a heavily-inclined treadmill after a casual run on the elliptical machine.

The important part of interval cardio training is that you’re confusing your muscles, and forcing them to adapt to varying intensities. Doing so creates a perfect storm of fat burning, as well as a much more interesting workout than plain cardio.

#4 – Iron Cardio

Some people very strongly hate running and other typical cardio activities, and would opt to get their cardio with a set of weights. For those people, there is Iron Cardio, a loosely organized series of intense workouts that engage multiple muscle groups, and gets your heart rate up after only a few reps.

In an interview with a local Fox affiliate, Iron Cardio Fitness Expert, Arthur Shrivers demonstrates some of the key Iron Cardio techniques that involve a set of dumbbells. Each of these are remarkably intense, and include Sumo Squat Presses, Jumping Squat Lunges, and an exercise called the Manmaker, which is a version of the burpee that implements extra dumbbell exercises.

Done at a rapid pace, it’s easy to see how these hyper intense Iron Cardio workouts can burn massive amounts of fat in a short time.

Related: 10 Best Adjustable Dumbbells

When most people think cardio, the most common activities that come to mind are running, cycling, and swimming. If you take a broader view of all of the sports, hobbies, and gyms out there, then cardio can consist of anything from jumping rope to boxing.

A lot of cardio workouts can be done outdoors and with little to no equipment, although fitness gear like step counters, running apps, and compression leggings can enhance your ability to perform cardio workouts.

Entire industries are dedicated to creating new and innovative types of cardio equipment for your home or gym, with the most popular being treadmills, elliptical machines, exercise bikes, and stair climbers.

A Brief Look at Strength Workouts

Strength workouts cover a wide array of exercises using gear, bodyweight, and even obstacles found outdoors.

The key aspect of strength workouts is that the resistance tears down the muscle, which causes it to adapt, repair itself, and grow. The amount the muscle grows depends on various factors, but through proper increases in resistance and fueling via amino acids, specific muscle groups can be targeted.

Everything about a strength workout is different from a cardio workout. Rather than rapid and long lasting, strength workouts are typically divided into repetitions and sets, and are designed to gradually increase your muscle mass and strength.

The Most Common Strength Workouts

Arguably the most common strength workouts in the world that do not require equipment are pushups, squats, and crunches. Each of those seemingly simple bodyweight workouts is legitimate in their own right, and targets the chest, quads, and abs respectively.

While those are common workouts in all settings, the majority of strength workouts are done with equipment. The most frequently used equipment for building muscle includes barbells, dumbbells, kettlebells, and weight machines.

Other innovative gear like steel maces and the resistance straps are also used for strength building, and there are numerous options regardless of your size, sport, and skill level.

Three Reasons Experts Disagree on the Issue


As semantic as it may sound, the issue of whether it’s best to do cardio or strength training first has become the most polarized debates in the fitness world. If you interview 100 personal trainers and coaches, each would have different opinions on the issue, and would explain different reasons for why they feel that way.

Although it seems like it wouldn’t matter whether strength or cardio comes first, there is research claiming that there are different effects depending on the order, so for those who want the optimal workout, the order actually does matter. Ultimately, the question of whether weights or cardio should be done first isn’t quite as crystal clear as people would like, and here are the three main reasons why.

#1 – Professional Bias

When looking at the opinions of experts, it’s a good idea to know exactly what they are experts in, because there is a solid chance it will influence their opinion. For example, if you’re getting the opinion of a trainer that looks like he’s on every muscle building supplement at once, then it’s safe to say you can expect a response that favors weightlifting.

The same could be said for the many female trainers who deal exclusively with weight loss clients and strongly emphasize cardio.

While judging people based on appearance isn’t right, experts that equally understand strength and cardio will typically be both muscular and shredded, rather than bulky or paper-thin. If nothing else, it’s smart to be aware of the type of training an expert emphasizes, because that often effects their judgement on key issues.

#2 – Lack of Education

A fitness expert may have 20 years of experience training people in a gym-setting, but if they don’t know the importance of research, then their advice might be questionable. The fact is, research and science are what leads to a legitimate answer, not some guy who swears by his method for unexplainable reasons.

Whether the discussion involves doing strength before cardio, which supplements are effective, or other fitness issues, look for intelligent experts who will use facts and research to explain support their arguments, because those are the reliable determining factors.

#3 – Selective and Limited Research

While there are studies that confirm small parts of the argument, there is currently no study that completely states cardio or strength is better to do first in all situations. As it stands, different studies can be used to support different sides of the argument.

For example, those who believe cardio should be done first could site the study from the Cooper Institute that showed triathletes may want to start with cardio, whereas those who argue for strength training first could cite the study that shows that cardio makes the blood acidic, negatively impacting the strength workout. This is further proof that knowing your goals is crucial to creating the optimal workout.

Knowing Your Goals Is Key

Whether it’s optimal to do strength workouts before cardio or vice versa will ultimately depend on your fitness goals. If you glance around at a typical mainstream gym, the types of people there and their motivations for working out will vary greatly.

Some will be new to athletics in general, and simply doing everything they can to stave off diabetes. Others will be improving their personal records, and seeing just how shredded and strong they can get. Whatever category you fall under can affect the optimal order of how you should approach your workout.

Slimming Down

Only if your sole goal of working out is to burn as many calories as possible, then cardio is most important and should be done first. The primary reason for this is because of the afterburn effect, in which calories continue to burn after the workout ends.

SportsAndFitness.com explains that when you do cardio first and place strength building as a secondary priority, your Excess Post-exercise Oxygen Consumption (EPOC) is higher, continuing to burn calories after your workout at a higher rate. In the event that slimming down is your top concern, then hitting your cardio workout first thing is shown to burn slightly more calories.

Building Muscle

For those who care more about building muscle and getting stronger rather than burning calories, there are studies and solid reasons to enter the gym and head straight for your favorite free weights.

The reason it makes a difference is because the nutrients used to grow muscle are very specific, but if you start with cardio, those same nutrients will very likely be burned as energy.

Starting with cardio uses some of the protein and other nutrients you need to build muscle, so it’s better to start with strength workouts if you care about strength at all.

Five Reasons to Do Weights Before Cardio

The vast majority of gym-goers want more than just calories burned. Most people, including both men and women, tend to want some degree of muscular growth and definition, in addition to burning fat and calories.

If your goal involves any form of wanting to improve strength, then it is definitely better to focus on strength and resistance workouts first, and here are five critical reasons why.

#1 – Save the Energy for Lifting

To make an impact on the muscles, technique, reps, and a challenging weight are all important factors. Therefore, if you’re jumping off of even a 30 minute run on a treadmill, then a lot of the energy you’ll need to push yourself to new weights or reps will have already been expended.

Furthermore, a certain amount of focus and energy are required to maintain proper technique when lifting, making it a smart idea to hit the weights first.

With weightlifting being a precise and skill-based activity, the extra nutrients and energy are best used on performing your resistance workouts to your full-potential, and using the remaining energy on cardio.

#2 – Gain Muscle Easier Due to mTOR Pathways

Not to get too deep into biology class, but doing cardio first has an inhibiting effect on your mTOR pathways, preventing optimal muscle growth.

Known as the Mammalian Target of Rapamycin (mTOR), mTOR is a special protein that relays various messages to muscles, including the order to grow. Long story short, mTOR pathways are vital to telling your muscles to grow, so having them inhibited by doing cardio first is not going to help your strength-building goals.

#3 – Safer to Lift First

While cardio workouts are relatively simple, repetitive movements, lifting heavy weights in specific movements requires skill and energy to do properly.

This is proven by the fact that fatigue is the top cause of injury among numerous weight lifters, and obviously, doing cardio first will sap a good amount of your energy.

Lifting in this drained state can have a negative impact on your performance, and you probably won’t do quite as many reps as you could before doing cardio. For these reasons, doing your strength and resistance sets before hopping on your preferred cardio machine is the safer plan.

Related: Olympic Weight Benches

#4 – Acidity from Cardio Causes Fatigue

One very specific effect of a cardio workout is that it alters the pH level of blood, making it more acidic. This acidic state makes it harder for muscles to contract, and can cause you to regress in strength and performance.

For example, trying to maintain a one-handed curl while your blood is acidic from cardio will make your biceps feel more fatigued than usual when contracting.

Even if injury doesn’t happen, fatigue can effect everything from motivation to recovery, so avoid it by doing strength workouts first. Aside from acidic blood levels, causes of fatigue are numerous, and include poor nutrition, lack of sleep, and improper technique.

#5 – Extended Cardio Can Break down Muscle

Cardio is fast-paced and demands a lot of fuel, and excessive cardio reaches a point where it grabs that fuel from muscles. This is another significant reason why those who care about building muscle should emphasize that workout by putting it first.

Many experts would put muscle building in its own phase, and advise against a lot of cardio until entering a shredding phase. Whatever your plan, it’s relevant to know that moderate cardio is good, but it should come after strength workouts if you’re concerned about gaining muscle.

The Only Reason to Do Cardio First

The only reason to prioritize cardio is if you’re simply trying to burn calories without concern for muscle, or are training specifically for a cardio-based event, like a marathon. In both cases, the weight training that follows would be light, and therefore, less likely to result in injury from fatigue.

That said, strength training is still advisable for those who are striving for weight loss, so definitely don’t limit yourself to just cardio because it will neglect important muscle groups.

A combination of both types of workouts is advisable for anyone, but if weight loss is top priority, then doing cardio first is shown to have a greater impact on the afterburner effect. That said, there is a way to stimulate EPOC levels beyond the capabilities of cardio.

A Superior Way to Stimulate EPOC

While on the topic of EPOC stimulation for weight loss, it should be mentioned that there’s a workout method that is even better than cardiovascular exercise. High Intensity Interval Training (HIIT) has proven to be a better method for slimming down and burning calories, and it combines various strength and cardio movements at a high intensity.

A primary trait of high intensity workouts is that they are functional, meaning they typically engage multiple muscle groups in a single exercise. Some examples of popular functional workouts include kettlebell swings, Turkish get ups, burpees, and squat presses with dumbbells.

The proven effectiveness of high intensity interval training is rapidly gaining popularity in fitness classes like Cross Fit, and is an ideal training method for people who want to reach peak levels of EPOC.

Final Say

In most cases, it’s proven that you’ll have a much more effective workout if you start with your strength training and conclude with cardio. Reasons for this include the skill, energy, and protein demands of weight lifting, as well as the superior conditions for growing muscle.

That said, we should all remember the reasons we’re exercising in the first place. For most people, their gym time is their scarce personal time, and the very fact that you’re there says that you care about looking and feeling your best.

The research definitely leans towards knocking out your strength training first, but like that research, let this guide be just one piece of the puzzle that leads to finding your ultimate workout.

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