Heart Rate Monitors + Strength Training

chris1816
chris1816 Posts: 715 Member
This is a hot topic that I have been wanting to tackle for a bit, as many people I see use HRMs for tracking calorie burn for strength training in addition to cardio, and question their accuracy.

First, let's get an understanding of something: Aerobic activity versus Anaerobic activity.

Aerobic Exercise

Aerobic exercise is what everyone here considers low intensity cardiovascular activity that can be supported by aerobic metabolism aka the body's ability to generate energy using primarily oxygen. Light to moderate cardio activities like short to medium distance running, dancing, swimming, walking, cycling etc can all be supported primarily by aerobic metabolism. As the body moves oxygen through the blood using the heart, a heart rate monitor can be used to gain a better picture of this than simply using equations based off body mass, height, age, sex etc. It is still an estimation, but in the case of an HRM during Aerobic exercise we go from ball park guesswork to a much tighter picture. This is where you see your body primarily use carbohydrates as an energy source before turning to fat (*kitten* your "fat burning zone", it's not that simple), but basically your body will be fueled by glycogen reserves, fat reserves, or some combination of both depending on the intensity of the activity. This is a slow and steady chemical reaction.

So let's be clear, running a distance over a long period of time at a moderate pace is Aerobic, but sprinting is not. This is where we start to get into the anaerobic flavor of things. Cardio based exercises are something that you can quickly become more efficient at however; run the same distance over periods of times and you will notice your heart rate will be lower each time, and thus the energy (calorie) demands can quickly diminish. This is where cardio kind of sucks for fat loss.


Anaerobic Exercise

Anaerobic exercise is high intensity exercise that begins to demand more than simple oxygen/glucose metabolism can quickly supply in short term bursts; this is where you get into training strength, power, speed, and the building of muscle (lean) mass over fat mass. This is the quick and intense activity (Strength training, HIIT, Sprinting, Jumping on top of things like a psycho), not the slow and steady. Not to try and get to deep into the specifics; there are two types of anaerobic energy systems: 1) the high energy phosphates, (ATP adenosine triphosphate) and CP creatine phosphate; and 2) anaerobic glycolysis. The translation of this is that anaerobic activity needs more ATP (cellular energy) in a short term than aerobic metabolism can quickly provide. This is why ( to put it simply) carbs are AWESOME for strength training as this is what provides all that sexy glycogen storage that can be quickly called upon for energy. This is also why I advocate creatine supplementation for anyone who strength trains because this is essentially a way to bolster those quick energy stores (see energy system number one above).

Fun fact time! Weight lifting is not an activity that requires a huge amount of caloric energy. The energy required to move 200 lbs one foot, say, in a bench press, is less than the amount of energy it takes to stand up. Standing up fifteen times isn't going to make a significant impact on caloric balance. But, the activity of repairing your muscles after a weight-training workout with sufficient adaptive pressure to cause microtears, in other words, a serious strength training workout, is extremely calorically demanding. Protein synthesis required to repair and build muscle uses a lot of energy, and if you're working at an overall caloric deficit, this energy is going to come from your fat stores while you sleep. They key words here are adaptive pressure, as this ties into why I throw out the word "progressive" along with strength training; you need to increase the work load to see the benefits.

(To support the above if you are a math nerd):

200lbs = 890 newtons
Work = Force x Distance = 890 newtons x 0.3 meters = 267 joules
1 Calorie = 1000 calories = 4184 joules

Is there some aerobic activation and cardiovascular involvement with strength training? Absolutely, your heart should be pounding after doing 5x5 back squats with a sufficiently challenging weight. Even that one set of five deadlifts can leave you panting for breath. If the activity is not sufficiently intense (you are using those girly 5lb dumbbells all day every day), this doesn't require that quick burst of energy and becomes pretty much an aerobic activity.


So after I just smacked you all in the face with a bit of science, what about the million dollar question. Does a heart rate monitor accurately measure caloric burn from strength training with progressive loading?

No, not really.

As I mentioned above you can get an idea of the general aerobic demands (which occurs even resting between sets), which is what your HRM and even basic mass based caloric burn calculations will go off of. However even then an HRM is almost as bad as the calculations on MFP or some websites for figuring this out as it is still just a ballpark estimation. The magic is really happening when you sleep and your body has to repair and adapt to all that damage you did earlier in the day. Your body has to go through extremely complex processes to turn energy you have taken in (food), and utilize existing fat stores to not only rebuild those damaged muscle fibers but also (in the case of caloric surplus or 30+% body fat) build new muscle fibers in order to recruit these to perform the lift more effectively the next time. This is why as you need to continually add more load to keep that adaptive stress magic happening.

A fun comparison for this is martial artists who break bricks without wrecking their hands. Did you know bone works the same way as muscle in the above? They continuously break smaller bricks, and actually create micro fractures (breaks) in the bones of their hands that will be repaired over time and be stronger. Then they break more bricks, create more fractures; rinse repeat. This is how these dudes move to plowing through a stack of f*cking cinder blocks with their fist.

In summary, focus less on what a HRM says about caloric burn while strength training and just figure out your TDEE and get on it. Spending 30-45 minutes, 3-4 times a week, with serious weights doing compound movements will work wonders.

Replies

  • beachlover317
    beachlover317 Posts: 2,848 Member
    NIce. Heybales was talking about this yesterday, but damn he is technical and it is not a language I speak. I've read this, but plan to go back later and dissect it. I would love for you to post some info on an appropriate training guide - meaning he touched on "not kickboxing" on rest days because of muscle over use. I'm finding that to be true, but would love to see what does mesh well with lifting. May be overthinking....I tend to do that.

    Thanks Chris.
  • chris1816
    chris1816 Posts: 715 Member
    Basically, the strength training routine should be key, and anything else should be built on that.

    Kick boxing is high intensity and therefore very demanding on fast twitch muscle; you are forcing your body to provide you with quick bursts of energy in a short period of time and thus facilitating anaerobic exercise and a demand on muscle fibers to deliver force, speed and power all at once. If you look at activities simply by the demand they put on you it becomes pretty evident.

    We can even dig into the nitty gritty of this with some. I listed swimming as a primarily aerobic activity and this is correct for the most part. In my case I have to avoid doing it before a push day as some of the same muscles used in pressing get used in swimming, especially if I switch from freestyle to breast stroke. Moving my 350lb *kitten* through the water at a decent base becomes pretty intense; so this actually works quite a bit of muscle unless I take it slow. Just like a short jog (20 mins) is aerobic, make it a sprint and it becomes anaerobic, and as such demands not just a steady flow of aerobic energy but makes your muscles begin to expend glycogen stores and react to stress almost like weight lifting.
  • beachlover317
    beachlover317 Posts: 2,848 Member
    So, looking at me specificaly, I still have about 55 pounds to lose and I love lifting. I want to lose more fat than LBM and so I will continue to lift 3 X a week. I have added some extra work (stretching, yoga, other things you have recommended) on my off days. My weekends are completely for rest. I don't really do any cardio anymore. Is this going to impede me losing the rest of my weight? Or should I just keep diet good and lift?

    BTW - I love kickboxing, but rather than putting too much stress on my legs, it is taxing my shoulders and arms from the punching. I haven't done KB for the last 2 weeks. That's allowed me to up my weights this week again.
  • chris1816
    chris1816 Posts: 715 Member
    If you enjoy it, keep doing it, but keep it as far outside of your lifting days as possible (like if you lift M-W-F, do it Friday or Saturday and give yourself Sunday to rest.

    Otherwise just keep your diet in order and keep lifting. It will be slow and gradual but effective.
  • beachlover317
    beachlover317 Posts: 2,848 Member
    I like that plan. :happy:
  • ccmandel
    ccmandel Posts: 143 Member
    Interesting...so if I'm on basically an upper/lower lifting routine, it's ok to do HIT on a day where I lifting upper, preferably before lifting so it doesn't interfere? But not on a day OF or AFTER lower as it will interfere with either energy for lifting or repair afterwards?

    Susan
  • chris1816
    chris1816 Posts: 715 Member
    ....yes.
  • LoraF83
    LoraF83 Posts: 15,694 Member
    Excellent info Chris.

    I wear my HRM for lifting, simply because I like to see the numbers - it makes me feel good. However, I know that they aren't accurate, and it's a moot point anyway since my intake is based on a cut from my TDEE.
  • beachlover317
    beachlover317 Posts: 2,848 Member
    heybales had an interesting opinion about lifting and HIIT: "if you have the strength left to do HIIT properly after lifting with your legs, you held back on the lifting. If bad knees and you have to, that would be valid use of it. But wasted muscles can't get the HR high enough to be true HIIT, which the article shares the studies that show how intense it must be for real benefit."

    This whole conversation was on his wall yesterday. That's why I'm glad Chris is addressing this as Mike is very technical.
  • chris1816
    chris1816 Posts: 715 Member
    heybales had an interesting opinion about lifting and HIIT: "if you have the strength left to do HIIT properly after lifting with your legs, you held back on the lifting. If bad knees and you have to, that would be valid use of it. But wasted muscles can't get the HR high enough to be true HIIT, which the article shares the studies that show how intense it must be for real benefit."

    This whole conversation was on his wall yesterday. That's why I'm glad Chris is addressing this as Mike is very technical.

    Actually that is 100% true, I can tell you I could never consider HIIT after any lift day in most cases. I like his statement on that. Who is heybales btw? lol
  • Barbell_Jules
    Barbell_Jules Posts: 358 Member
    Great information here. I read Mike's update yesterday as well and I'm still a bit confused... from what I understood if I'm not doing some sort of HIIT, I am not doing any good for my body. I do cardio on my "rest" days, but rather than doing HIIT, I am now just taking a brisk 30 minute walk. Is this pointless?

    I stopped wearing my HRM while lifting because I read that the calorie burn is inaccurate. And I have my activity figured into my TDEE using Mike's spreadsheet (which I am still trying to figure out how to tweak) so it really doesn't matter what my actual calorie burn is anyway. Though, I do wear it when I do cardio because I like to see the numbers and know what I did actually burn.
  • McAlyna
    McAlyna Posts: 123 Member
    Great post Chris!! :flowerforyou:

    I have a question for you, I am currently doing SL5x5, 3 times a week now on week 12. I only do cardio 1-2 times a week (walking treadmills 3.2 mph with inclines 20-30 mins each sessions). I am eating between 1600-1800 cals a day. Am I doing enough exercise and eating enough?

    Btw, I have a desk job. I wear fitbit all day so on my rest and not working day, it shows that I burn around 1750-1800 and my workout day, I burn up to 2100.

    After I finish the 12 weeks SL program, should I keep doing or should I switch to something else?
  • chris1816
    chris1816 Posts: 715 Member
    Great post Chris!! :flowerforyou:

    I have a question for you, I am currently doing SL5x5, 3 times a week now on week 12. I only do cardio 1-2 times a week (walking treadmills 3.2 mph with inclines 20-30 mins each sessions). I am eating between 1600-1800 cals a day. Am I doing enough exercise and eating enough?

    Btw, I have a desk job. I wear fitbit all day so on my rest and not working day, it shows that I burn around 1750-1800 and my workout day, I burn up to 2100.

    After I finish the 12 weeks SL program, should I keep doing or should I switch to something else?

    In regards to your first question, are you seeing the results you want fat loss wise? How are your strength gains?

    I would say evaluate how you feel about switching programs at that point but you may just want to continue with SL for a good while before changing anything up. At the most you can maybe add a bit of accessory work.
  • McAlyna
    McAlyna Posts: 123 Member
    Great post Chris!! :flowerforyou:

    I have a question for you, I am currently doing SL5x5, 3 times a week now on week 12. I only do cardio 1-2 times a week (walking treadmills 3.2 mph with inclines 20-30 mins each sessions). I am eating between 1600-1800 cals a day. Am I doing enough exercise and eating enough?

    Btw, I have a desk job. I wear fitbit all day so on my rest and not working day, it shows that I burn around 1750-1800 and my workout day, I burn up to 2100.

    After I finish the 12 weeks SL program, should I keep doing or should I switch to something else?

    In regards to your first question, are you seeing the results you want fat loss wise? How are your strength gains?

    I would say evaluate how you feel about switching programs at that point but you may just want to continue with SL for a good while before changing anything up. At the most you can maybe add a bit of accessory work.

    Scale, no result but I pay no attention to it. It has been mean to me since I upped my calorie intake and lifting heavy. Measurements, I am sux at it. Pictures, I do see changes.

    I had the PT did the 3 points body measurement the first day I started SL and after completing 6 weeks of SL, I've lost 1.7% bf. I will do it again sometimes next week after I finish 12 weeks.

    I started all my lifts at 45#, the bars. I progress, not much but consider good for me. For the past 6 weeks, instead of adding 5# every sessions, I do fractional weights 3#, I've been repeating same weight a couple sessions before adding more to make sure my form is somewhat correct.

    Here's my current stats:
    Squat - 120
    Bench - 75
    Row - 88
    OP - 55
    DL - 128

    I will be doing SL till I can't up the weight any more.

    Thanks again!
  • chris1816
    chris1816 Posts: 715 Member
    Sounds like a plan, you've been progressing, period and that is what matters. I wouldn't worry about switching to Madcow or anything like that. Do Stronglifts for a while, only consider a different routine when you are eating at a surplus and looking to bulk a bit I'd say.
  • McAlyna
    McAlyna Posts: 123 Member
    Okay, now raise another question. How do I know when to bulk? Do I need to bulk or just keep trying to burn fat?

    Sorry, newbie still.
  • chris1816
    chris1816 Posts: 715 Member
    Whenever you want to.

    You cut down until you have a level of body fat that is acceptable for you that you feel comfortable gaining a bit of weight/fat back along with muscle. You stop bulking when you feel like it, then cut down again.

    Rinse repeat.
  • McAlyna
    McAlyna Posts: 123 Member
    Whenever you want to.

    You cut down until you have a level of body fat that is acceptable for you that you feel comfortable gaining a bit of weight/fat back along with muscle. You stop bulking when you feel like it, then cut down again.

    Rinse repeat.

    Ahh... Now I understand.

    No bulking as yet. I have a long way to go then. :laugh:
  • nacs246
    nacs246 Posts: 93 Member
    Thanks for the Post Chris.
    I think the most important point and to put it more simply is that the "Afterburn" after a weight training is extremely important and what most people don't take into account. After a lifting session the body continues burning calories at a higher rate than just a cardio session.

    However I must say I am not totally convinced on the fact that the HRM does not give you an accurate burn? If it is showing an increased heart rate ,hence , more energy thus higher calories burnt why can't you consider using this as an idea of extra calores burnt? Then whats the point of having an HRM?
  • chris1816
    chris1816 Posts: 715 Member
    Thanks for the Post Chris.
    I think the most important point and to put it more simply is that the "Afterburn" after a weight training is extremely important and what most people don't take into account. After a lifting session the body continues burning calories at a higher rate than just a cardio session.

    However I must say I am not totally convinced on the fact that the HRM does not give you an accurate burn? If it is showing an increased heart rate ,hence , more energy thus higher calories burnt why can't you consider using this as an idea of extra calores burnt? Then whats the point of having an HRM?

    Point of an HRM - to accurately measure caloric burn in relation to aerobic activity, so for cardio it is great. It handles this job well especially when a chest strap is involved.

    Lifting is not an aerobic activity, at least not strictly, and not even mostly. You can't gauge how much energy is going to be spent after the fact on synthesizing new protein into lean muscle mass. It simply does not use the cardiovascular system for energy transport the way aerobic activity does...you literally have quick stores of energy in your muscle fibers that anaerobic activity friggin incinerates to get that quick, explosive and powerful movement going.

    This is what water retention is all about; you retain water in glycogen stores. More carbs = more glycogen = more water swelling the cells as a by product all so you can carry around this quick use energy. Creatine supplementation is also associated with water retention for this same reason; you are saturating the cells with creatine phosphate to use for that quick burn. Your muscles can't wait for your heart to pump blood and oxygen around to accurately fuel this; so it gets that energy another way. As such if it is not involving the heart as much, a heart rate monitor doesn't give you an accurate or complete picture.
  • evdenapoli
    evdenapoli Posts: 164 Member
    This is great! tks!