Cardio Before or After Workout: Decoding the Fitness Dilemma

One of the oldest dilemmas for fitness enthusiasts is whether to do cardio or weights first. Both sequences offer unique benefits and affect your workout results. So, the first step is to define your fitness goals.

Whether you’re looking to improve cardiovascular health, increase muscle strength, or burn fat, understanding the strategic placement of cardio and weight training in your routine can make a significant difference. The answer is quite nuanced and depends on the goals you just set, your experience level, recovery, and overall response to different training types.

So, before you lace up your sneakers, let’s break down the best ways to structure your workout routine to align with your goals.

Combining cardio and resistance training

A few years ago, many fitness enthusiasts were either devoted to cardio, focused solely on strength training due to the belief that ‘cardio kills your gains,’ or were part of a distinct group of cross-fitters. Recently, we've seen a rise in hybrid athletes, a term used to describe those who combine cardio and weight training. Combining cardio with strength training is a well-rounded approach to fitness. When done correctly, both forms of exercise can complement each other; however, it's essential to understand the dynamics involved to tailor your routine to meet your specific goals.

Effects of cardio vs. resistance training on energy levels

Both cardio exercises and strength training deplete the body’s energy reserves differently. Cardio exercises, like cycling, running, swimming, hiking, and dancing, involve a continuous activity that uses big muscle groups. During these exercises, the body relies on oxygen to fuel the muscles through aerobic pathways. Consistent cardio training improves your stamina and the ability to use oxygen effectively (aerobic capacity), allowing you to increase the duration or intensity of the workout. However, it can significantly tire you out, especially when pushing yourself.

Conversely, weight lifting involves short, intense bursts of activity, focusing on specific muscle groups. This type of training, known as anaerobic exercise, relies on glucose stored in the muscles instead of oxygen. The goal here is to work a target muscle group thoroughly to trigger growth, muscle power, or build muscle endurance. While this training also leads to fatigue, it’s typically confined to the muscles you've exercised, unlike the overall tiredness you might feel from cardio.

However, exercise is just one side of the coin, and proper nutrition is required to fuel both workouts.

The interference effect

It is suggested that cardio before lifting weights can hinder muscle strength and growth because the muscles are pre-exhausted with cardio. This is called the interference effect. However, this topic is still controversial and stirs debate as studies yield mixed results due to people's individual responses and adaptations to exercise.

A meta-analysis of 21 studies revealed that overall power was significantly lower in the combined training group compared to the resistance training-only group. However, there were no significant differences in maximal strength or hypertrophy between the two groups. Additionally, aerobic capacity was not negatively affected by combined training; in fact, resistance training may even enhance cardiovascular performance, as evidenced by elite endurance athletes.

The chronic interference hypothesis argues that combining weight with endurance training in the long term could lead to overtraining by prompting competitive adaptations. Essentially, weight training focuses on achieving peak (near maximum) outputs in short bursts, whereas endurance training is aimed at extended activities with lower intensity. As these training styles encourage very different body adaptations, mixing them without strategic planning can overwork the body, making it less efficient at improving in either.

Despite this, nuances exist: differences in individual recovery rates, types of cardio, and the training's frequency and duration play significant roles. For instance, short cardio sessions like sprints seem to have little effect on resistance training outcomes. However, this interference is less of a concern for those exercising primarily for general health or aesthetics. For them, the focus should be on designing a balanced workout regimen rather than maximizing every aspect.

Combining training: same day or separate?

Combining or hybrid training can enhance your overall physique and health, whether by integrating cardio into your strength program to create a calorie deficit or improve overall fitness. Either way, there are a couple of ways you can go about it.

There is no single best approach, as it heavily depends on your goals. I focus on resistance training four times per week and core and cardio one time. Lastly, I add 10–15 minutes of Stairmaster after an upper-body workout if I know I will not get enough steps that day.

However, the main way I get my cardio is my daily life without labeling it as a workout. I train in the morning and then bike as fast as I can to work to avoid traffic and make it on time, which ends up being like a 15-minute cardio finisher. On days I do not train, I walk briskly for around 40 minutes back and forth, which also counts as steady-state cardio. My favorite yet often overlooked cardio form is dancing my heart out at a live concert.

The point is, if you are not training for a marathon or another endurance-based goal, your cardio does not need to be an optimized separate workout, nor does it need to be set in stone. Look at it as a tool that can be adjusted to match your day, week, and overall lifestyle.

What happens if I do weight training before cardio?

The general recommendation is to do strength training first if your primary goal with fitness is strength, muscle gain, bodybuilding, and overall strength training benefits. Also, if you just want to be ‘toned’ and not bulky, your main goal is still building muscle, just being lean enough to look lean and compact.

Lifting weights first enables you to focus your best effort on the workout, allowing you to push yourself to failure or close to it while maintaining proper form. This approach may help you maximize your performance, strength, power, and overall gains. Additionally, doing cardio beforehand can lead to fatigue, which increases the risk of injury due to decreased attention to technique.

Resistance training can increase oxygen consumption and fat-burning post-exercise for up to 48 hours due to the release of catecholamines and growth hormones. Catecholamines rapidly break down fat, while growth hormone, peaking 120–160 minutes after exercise, raises free fatty acid levels in the blood. This increases fat availability for subsequent cardio sessions.

Taking a rest of up to 20 minutes between lifting and cardio has been shown to significantly enhance fat oxidation during a 60-minute endurance session compared to endurance training alone. With longer rests of 120 minutes, fat burning doesn't increase in the first 30 minutes but rises significantly in the latter 30 minutes, even higher than in the 20-minute rest test. Thus, resistance training followed by cardio with minimal rest time may be a more efficient approach for fat burning than doing cardio alone. However, it's important to note that effective fat burning and weight loss ultimately hinge on maintaining a calorie deficit, and the study referenced involved only 10 participants.

Adding cardio after your lifts also has the benefit of saving time and being easier mentally. Instead of needing to prepare: get ready, warm up, go somewhere, etc., you just hop onto a machine of choice, put on a good playlist, a YouTube video, or do some scrolling. I found 15 minutes once or twice weekly is enough to improve my cardio endurance over time without making me feel exhausted or interfering with my training split. There is no optimal time to do cardio. What matters more is the intensity and challenging yourself.

When can cardio come before weights?

Of course, doing cardio before lifting may be beneficial in some instances:

• Warm-up. Doing light cardio 10–15 minutes before your lifts may help you warm up, especially if you work out in the morning or drive to the gym. However, still do some targeted mobility.
• Endurance goals. If your main goal with training is improving endurance, do cardio first. Resistance training can significantly decrease the rate of force and time to exhaustion during endurance training. Also, doing cardio after lifting is physiologically harder than doing cardio alone or prior.
• You prefer it that way. If you do not have strict goals in mind and are training to feel good and have found that doing cardio before lifting does that for you, keep doing so. Adaptations and responses to exercise are highly individual, and there is no optimal way for everyone.

Suppose you prioritize endurance sports and are doing weight training to help with performance. In that case, you may want to keep the sessions separate and do resistance training one day and endurance training the other. Because doing cardio first can negatively affect your strength and muscle gains that fuel your endurance sport, you may not benefit most from your sessions. Doing cardio after lifting will not allow you to give your whole effort to your sport. So, if you have goals beyond general health and wellness and are looking for competitive results, it is best to consult a personal trainer to get a training plan tailored to your goals.

What other factors influence my workout results?

One way to determine which you should do first is to look at the expected intensity of the workout. High-intensity workouts will deplete your energy and affect your performance in the subsequent activity. If you want to get an intense lifting session in, aiming for personal records, hitting (close to) failure, and overall improvements in form, strength, and explosive power, do lifting first. Conversely, if you want to improve your sprints and do some lighter lifting, do cardio first.

Next, the type of cardio may also influence the order. HIIT or intervals may be better done before lifting, while steady-state cardio, like running, cycling, or stairs, can be done after. Again, it is about what you want to put your peak energy into.

Lastly, you must look at your weekly volume and movement outside your workouts to prevent burnout. If you lift a couple of days per week, consider including cardio on rest days. If you lift five times per week, you may only want to add short finishers or even focus on steps outside the gym to let your body recover. Either way, ensure you are not over-pushing yourself to reach a maximum in both lifting and cardio sessions. Set your priorities, plan your week, and make sure you have dedicated rest days.

How do I choose the right order for my fitness goals?

I always emphasize that your goals dictate your approach, but you might not be clear on what those goals are or the best strategies to achieve them. Seeking personalized advice from a trainer is recommended.

For beginners, starting with weights may be more beneficial to ensure they have enough focus and energy to lift with good form, reducing the chance of injury. Also, starting with shorter and less complicated sessions is better to prevent burnout and not feel overwhelmed.

Once you have gained enough experience with lifting and have built up a solid routine, experiment with adding cardio. Ultimately, it depends on what feels best for you, so do not be afraid to try different approaches and listen to your body.

Final thoughts

Consistency is key to progress in your fitness journey, so establishing a workout plan that aligns with your goals and that you can stick to is the first step to long-term results. It allows you to build and maintain momentum, ensuring that each workout contributes to your health and goals.

That being said, adapting your routine as you gain more experience is vital. From personal experience, the importance of finding a routine that works for your body and your current lifestyle cannot be overstated. It needs to be enjoyable and fit your current schedule without being overly complicated or leaving you burnt out. Life changes, such as starting a new job, moving, or adjusting to new responsibilities, may require adapting your fitness routine. That's not slacking — that is smart adaptation and key to success.

Moreover, shifting your fitness goals over time and modifying your training to reflect those changes is perfectly okay. Remember, your fitness journey is just a journey, not a destination. Adjustments along the way are not only expected but necessary for sustained growth and satisfaction. So, it's essential to educate yourself about the different approaches, techniques, and methods in fitness. Understanding the ‘whys’ behind each will help you make adjustments that suit you best. However, when you're just starting, seeking professional advice can provide valuable foundational knowledge and ensure you learn the correct forms and practices.