Unless you have been living under a rock you already know all the great benefits of HIIT and what METCONS are and how to perform them. More than likely, you have already been doing some form of HIIT in your training for awhile now.
HIIT & METCONS get results hands down. There is no denying that fact. Myself and my students have all seen great benefits from sprinting, lifting weights and using just bodyweight exercises to perform various styles of HIIT. From AMRAPs, EMOMs and multiple styles of circuits and Tabata styles, everyone loved them and they really pushed us physically and mentally.
Beyond being fun and challenging, there is a lot of scientific research showing how they burn fat , build muscle  and improves your overall physique for that athletic build we are all striving for. But is there a negative side to performing too much HIIT? Are there any negative effects when we combine it with our weightlifting and strength training programs? Do we never have to do any steady cardio again or can we just do HIIT?
If you have never asked yourself this, maybe it is time to take it into consideration. Today we are going to cover these questions and also let you in on a little secret. If you are only performing HIIT and lifting weights you are only working one-half of your cardiovascular system. That is 50% you are NOT using. Learn how to use 100% and get the most out of your training and your body by following this 1 simple tip.
You have already learned from the research and studies out there that when performing HIIT and METCONS your heart rate jumps higher than on an elliptical or bike. It spikes and drops to recover and then spikes again. Hence “intervals” technically in your heart rate as well as the intervals you are performing. With this style of training you know you break into the anaerobic cardiovascular system very fast.
Since you already know that HIIT jumps your heart rate and your anaerobic system, take a second and think about how you lift when you strength train. You will exert effort for a certain amount of time to perform your reps and then you take a rest after you complete your set. Essentially another “interval”, especially if you are timing your rests between your working sets. #ProTip
So, we see the praise of strength training, we see the praise of HIIT and METCONS and both are producing great results. Both burn fat, build muscle, increase Excessive Post Oxygen Consumption (EPOC)  and overall make you feel like a BOSS when you finish. But by only working this one side of our cardiovascular systems we are essentially only using half of our bodies’ full potential. What will happen when we work our aerobic cardiovascular system too?
Nowadays it seems that unless you are a runner, steady-state cardio is the plague. People just loathe walking outside or being on a treadmill. There is a reason people say, “CARDIO SUCKS” because you simply feel that you are not getting anything out of just walking.
But what if you (like me) don’t like running? I loathe running and with research proving that over 50% of runners get injured  and that running actually damages muscle, like the normal “marathoner” picture you see. It’s just not the body style that resembles an athletic build, so why would you do that to yourself?
This is where the fight comes in–how can you get the benefits from your aerobic system when the most common versions of steady-state cardio are long, boring and not providing the results that you desire?
You need a way to challenge yourself. You need a way to track your progress and to feel you actually accomplished something when you finish instead of just wasting your time mindlessly walking that’s not producing results.
Believe it or not there are multiple reasons that you should incorporate some version of stead- state cardio training into your programming. Everyone loves lists, so here are my Top 5 Reasons that you, as a lifter and someone after that statuesque body, needs this training.
1) It makes your heart stronger, which increases your V02Max that will transfer over into more success for your weight lifting and HIIT style training. You will be able to do more work and recover faster. 
2) It battles DOMS (Delayed Onset Muscle Soreness) by producing cellular adaptations that raises how fast your body can remove lactate. This, in turn, helps your body not accumulate excessive lactate until higher intensities. 
3) Even though HIIT gets a lot of love for fat burning, only steady-state cardio has been shown to actually oxidize the most fat cells in your body at 65% of your V02 Max. 
4) If you incorporate some sort of steady moderate exercise as an active recovery between your lifting sessions or intense HIIT/METCONS it will help your muscles and body recover faster than doing nothing and taking a “rest day”. 
5) We already know the huge benefits that lifting gives for boosting our muscle building hormone testosterone. And surprise, surprise, steady-state cardio has also been proven to raise dihydrotestosterone in men. 
The Perfect Trinity, How to Use All 3 Styles in Your Training:
By now you can see there are some serious reasons to take a look and re-evaluate how much steady-state cardio can help you. It’s very easy in the fitness world to pick a “team” and go hard for that one style of training. Be it Crossfitting, HITTing, Lifting or being a “cardio bunny”. But we have to realize that our body has different systems that work all together as one. They are synergistic, you need to train all aspects in order to be the best version of you and to look your best.
Even though it may seem like I am “hating” on HIIT and METCONS, I truly think they are great! Plus, the science behind it cannot be denied. So the trick is mixing them all together to get the most out of your time. Here is a simple way and my normal training set-up that myself and my students do that are getting some out of this world results.
I’m a big fan of weight training 3 days a week. You can work full body or even break those days into certain splits if you want, whatever works best for you. I like to add a little HIIT ab circuit after weights to really cut up the abs. Try picking 3 exercises that really hit your abs (Alternating V-Up, Knee Grabs and Mountain Climbers) and perform each exercise back to back for 30 seconds.. Rest 1 minute after performing all three exercises and then repeat.
The “in-between” lifting days is where I throw in my steady-state cardio. My favorite style is an incline treadmill, but there is a trick. Raise the incline to a point that’s comfortable to you, pick a speed that is comfortable to you, then check your heart rate. The challenge is to keep your heart rate between 130-140 beats per minute and maintain that pace for a minimum of 30 minutes. If you get bored by walking on a treadmill, use the time to better yourself. Read a book, listen to podcasts, watch movies from your cell phone or even just spend the time talking to someone.
If you hate being inside for your cardio, then go outside. Just challenge yourself and make sure you are staying in your target heart rate of 130-140, find a hilly road or just be prepared to walk at a faster pace. This is not the same as walking around shopping where you stop, look and start again. It has to be steady and consistent for at least 30 minutes to get the full benefits from your aerobic cardiovascular system.
If you are an overachiever and you decide to have a 6th day of training, that would be a great day for a full-on HIIT/METCON session. Just make it short, fast and intense but be sure you are eating enough food as well as taking the 7th day as a full rest day. You have always heard “abs aren’t made in the gym” the same can be said for muscles in general. You don’t get bigger and stronger by being in the gym, it’s a matter of how you recover to help you build that strength. But that is a topic for another blog.
You might be hesitant to try this, but I assure you that you will sweat and burn fat as well as help your body speed up recovery! It also gives you greater potential to break through current plateaus that may be holding you back. Try it out and let me know your results, I promise you won’t be disappointed!
About the author
Jay Kali is an Internationally recognized Strength and Conditioning Specialist who has owned/operated two fitness facilities and an Online Coaching system, which combined has trained over 3,200 students in the span of 5 years.
He has earned his certifications as a Specialist in Strength and Conditioning, as well as a Certified Fitness Trainer, both earned through the International Sports Science Association. Jay is also a 300-Certified Yoga Teacher in Power Yoga from Aura Wellness Center.
Jay is currently on a mission to help women all over the world get stronger physically and mentally, even if they don’t have time to make it to the gym.
Footnotes and links to research: