Can You Do HIIT While Bulking? (Cardio While Bulking Guide)

When building a physique you will typically go through two phases with a dedicated focus on a singular goal. That will either be a cutting phase where your focus is on fat loss or a bulking phase where your focus is on muscle growth. 

There is also a maintenance phase where you look to gradually build muscle with a smaller calorie surplus whilst maintaining a low body fat percentage however the vast majority of beginners and intermediate level lifters will not be looking at this option. 

With each phase there are also a number of tools that you use to build your physique, these are weight training, cardio, diet and rest/recovery. When you apply all four of these in an effective manner then you will start to see noticeable changes in your progress and physique. 

Most people will have a love/hate relationship with cardio and would therefore want to know whether you should do cardio while bulking for a number of reasons. One of the most popular (but intense) methods of cardio is High Intensity Interval Training (HIIT).

Can you do HIIT while bulking? While you can do cardio while bulking it’s best to do a low impact form of cardio like LISS. HIIT cardio will impact your recovery capabilities and will therefore detract from your weight training sessions so it would be best not to do HIIT cardio when bulking.

HIIT training requires a high energy output which leads to more calories burned, a great protocol to use when cutting but when bulking it seems counter intuitive to burn calories when you want to be consuming a calorie surplus to support muscle growth. 

HIIT is a very demanding form of cardio and it therefore causes confusion as to whether or not you should do any form of cardio when bulking. 

Should You Do Cardio When Bulking

Before getting into whether you should do HIIT while bulking it’s worth answering the question of whether or not you should do any form of cardio when bulking

The purpose of a bulk is of course to put on as much muscle mass as possible and a caloric surplus is usually needed in order to support this (though beginners can still build muscle without necessarily needing this surplus). Cardio however, is a tool that is used to burn calories by increasing energy expenditure which is seemingly the opposite outcome that you would want when bulking. 

This therefore led to a mindset of stopping cardio when you bulk and then adding it back into your routine when on a cut. For most this is an easy decision but for those that actually enjoy cardio you might be wondering whether you should do this while bulking. 

Benefits of Cardio When Bulking

As with most things when it comes to physique development, the answer to most questions is always “It depends”. This is also true with cardio and bulking as no two people are the same and everyone will respond differently to a certain stimulus. 

If your goal is purely to gain size in any way possible (if you are the skinniest hardgainer for example) then this is the only time I’d say it’s ok to go easy on the cardio when bulking. Someone training purely for strength will also see marginal benefit from cardio but they will see some benefit. 

For most people I would therefore recommend adding in some form of cardio even when bulking to take advantage of some of the benefits that cardio in general provides. 

Nutrient Partitioning

Nutrient partitioning is how your body best makes use of the calories and macronutrients that you consume and for the purpose of physique development, we are mainly concerned with how the body utilizes carbs (and fats to an extent). 

Nutrient partitioning is a genetic factor, there are those that eat whatever they want and build nothing but muscle mass and then there are those that consume a small amount of sugar and have suddenly gained a few pounds of body fat.

During this process you can either utilize nutrients for the skeletal muscles (protein for muscle repair/growth and carbs to replenish muscle glycogen to fuel workouts) or these nutrients can instead be stored as body fat. 

The second option is one that you don’t want, especially when bulking! While cardio is not the answer to shuttling nutrients to skeletal muscle instead of being stored as body fat it can help support it. 

Active Recovery

Active recovery essentially means doing something low impact with a low intensity to improve blood flow and aid recovery. Yoga is often considered a great form of active recovery as it involves stretching the muscles and facilitates pumping more nutrient rich blood into the area. 

Cardio is another form of active recovery when doing a low impact option like walking, cycling or swimming. When bulking you’ll be lifting heavy and frequently in order to stimulate muscle growth and recovery becomes a priority when bulking in order to optimize this process. 

As with the point about nutrient partitioning, cardio won’t help you to recover instantly in between weight training sessions but it will help to speed up the recovery process allowing you to train harder and more often. 

Cardiovascular Conditioning

Finally, when bulking you’ll be training hard and eating a lot however building a physique does not solely come down to training your muscles. It’s important to maintain your cardiovascular conditioning for a number of reasons:

  • Cardiovascular conditioning will allow you to train harder on a bulk (you can’t train to your optimum level if you fatigue too quickly)
  • Minimize excess fat gain that comes with a calorie surplus (minimize doesn’t mean prevent)
  • Partition nutrients better (discussed above)
  • Improves blood flow and recovery

Can You Do HIIT While Bulking

As you can see, cardio is important when bulking for a number of reasons however, it needs to be specified that any form of cardio on a bulk needs to be a low-moderate intensity so that it doesn’t interfere with your primary focus which is muscle growth.

HIIT cardio is unfortunately a high impact form of exercise and therefore does not compliment heavy weight training well. When looking at whether you can do HIIT cardio while bulking it really comes down to two specific factors:

  1. Is your goal solely to build the most muscle mass in the shortest amount of time
  2. How much body fat are you prepared to gain during a bulking phase

These two points are really the deciding factor as to whether or not you should do HIIT when bulking. As mentioned at the start of the article, if your goal is purely to build muscle (or size in general) during a bulk then HIIT will detract from this and you should not do HIIT while bulking. 

If however, your bulking approach is to minimize fat gain and build muscle over a longer period of time then you could add some HIIT training into your routine though I’d still recommend that you instead use a low intensity steady state (LISS) form of cardio. 

The reason for this is because HIIT style cardio and weight training do not work well together when bulking and HIIT will impact your ability to lift weights and recover in between sessions. 

Can You Do HIIT And Weight Training

Firstly, there is nothing to say that you can’t do HIIT and weight training together. When it comes to building muscle (or a physique), there are no set rules that you need to follow as everyone responds differently to training. 

With that said there are definitely certain things that you can do in order to optimize your results and when it comes to building muscle the key is to create mechanical tension and metabolic stress for a muscle through training, get progressively stronger each session, consume enough calories (with an ideal macronutrient ratio) to fuel workouts and facilitate muscle repair and finally recover in between sessions. 

I’ve simplified the muscle building process because HIIT style cardio has a direct impact on all of these factors when weight training with the sole purpose of muscle growth. If your primary goal is fat loss then HIIT is an excellent tool to use while weight training is a secondary priority that is used to maintain your current level of muscle mass whilst you burn body fat. 

When building muscle however, the demands of HIIT cardio significantly detract from your ability to optimally train and recover from your weight training sessions. HIIT cardio requires the use of fast twitch muscle fibres which are the muscle fibres more sensitive to muscle growth with weight training. 

Sprinting for example requires explosive contractions for the leg muscles and uses a high number of fast twitch muscle fibres (a contributing reason as to why sprinters are often huge and muscular whereas marathon runners are smaller and skinny!). This not only fatigues these muscle fibres but then requires time to recover from them. 

Time spent recovering from cardio is time that you cannot dedicate to weight training for that muscle group. HIIT cardio also has a high energy output and burns a lot of calories (200kcal – 500kcal on average) which means that you will need to consume more food in order to maintain the calorie surplus required for a successful bulk. 

Therefore it’s not the case that you can’t do HIIT and weight training together as an average gym goer, you could do 2-3 days per week full body or upper/lower body weight training and 2-3 days per week doing HIIT cardio. 

As a non average gym goer with a specific goal of maximizing muscle growth however, then HIIT will detract from your wait training sessions and should therefore be replaced by a low impact LISS routine done 3-4 times per week instead. 

Will HIIT Make You Lose Muscle

Cardio Is just one component that factors into the overall picture when it comes to growing, maintaining or even losing muscle mass. When considering whether HIIT will make you lose muscle you need to consider how it would do this and how large the impact would be. 

The largest contributors to muscle mass are regular resistance training, sufficient calorie consumption (in particular protein) and adequate rest and recover. These three components are essential when it comes to muscle growth or muscle loss. 

HIIT factors into this equation because it increases your calorie demands, increases the work rate of a muscle group and impacts on the length of time required for recovery. Therefore HIIT doesn’t have a direct impact on muscle loss however it will contribute to the key factors that do. 

Doing HIIT cardio will not make you lose muscle, there have been no studies to show this to be the case and the issue comes when you don’t track your weight daily or adjust your calorie requirements based on your energy demands. 

Increasing energy output means that your calorie requirements increase, if you don’t consume more calories to match this then you will likely put yourself into a state of a caloric deficit. A calorie deficit leads to weight loss which can be in the form of fat loss or muscle loss as your body breaks down fat storage and muscle mass in order to use it for energy when in a deficit. 

Therefore as long as you maintain an overall calorie surplus, continue resistance training and recover sufficiently from workouts then HIIT will not make you lose muscle mass and studies have shown that HIIT can actually help preserve and prevent the loss of muscle. 

Can HIIT Support Muscle Growth

In a further point to that last sentence, not only will HIIT cardio not make you lose muscle mass but a study has been done to show that while HIIT isn’t necessarily beneficial to improving lean muscle mass it can help you preserve and prevent the loss of lean muscle mass. 

Moderate intensity continuous cardio (MICT) like long distance running is actually something that can contribute to a loss in muscle mass. HIIT helps recruit fast twitch muscle fibres and increases the proportion of fast twitch fibres in a muscle in relation to slow twitch muscle fibres. 

This is beneficial because the fast twitch fibres are those with the highest hypertrophy inducing effects (muscle growth). Therefore not only is it the case that HIIT won’t lead to muscle loss but can actually help support muscle growth. 

Conclusion

While HIIT can be shown to be beneficial in supporting muscle growth it’s important to note that supporting and optimal are not the same things. If you want to maximize muscle growth or size in general (for the skinny ectomorphs out there) then It would be best that you avoid HIIT style cardio when bulking. 

Instead look to do very low impact LISS cardio like a 30 minute daily walk or cycle in which you keep your heart rate low and muscle activation/engagement equally low. Also if you are looking for any further cardio tips during a bulking or cutting phase then you should check out some of these articles:

Is cardio necessary for cutting
How to do cardio without losing muscle mass
HIIT before or after weights

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