Why I'm not for cardio and resistance concurrently

Thank you for posting this. Very informative.

The drag is that there's not a sufficient number of days in the week to do everything I want to do. I want to lift 3x to build muscle & beat you at arm wrestling. I want to run multiple times so I can be ready for my races/mudrun. I want to do my salsa fitness class & pole dancing class bc they're hella fun. Solve that, science!

Thank you for posting this. Very informative.

The drag is that there's not a sufficient number of days in the week to do everything I want to do. I want to lift 3x to build muscle & beat you at arm wrestling. I want to run multiple times so I can be ready for my races/mudrun. I want to do my salsa fitness class & pole dancing class bc they're hella fun. Solve that, science!

I would have to agree. There never seems to be enough days or times in the week to fit everything in that I like to do. How do you find the time for all of it?!

there's no rule that you have to do everything in a week. I workout on a 9 day cycle, works for me.

Well, you're one of the folks on here who finally got it through my head to drop the low weights/high reps for heavy lifting (heavy being a relative thing of course, I'm still working on building up). I love it and am seeing great results from it. So, thank you, good sir!

Good stuff my dear, I'm happy I could be a small influence towards your better health! :happy:

My upper-body is definitely spent from my weight session but my legs do have that last little bit of oomph left. So maybe I need to add in another weight training routine or two for my legs instead of doing the few intervals I'm doing? Your thoughts?

Again, thanks in advance.

only if you want to, there's no law that says you have to be totally drained after a workout, especially if you're targeting a specific muscle group. if you're doing heavy weight, the group you're targeting should be exhausted, but other groups can be fine. I often walk out of the gym on upper days feeling fine in the legs, could do a 5 mile moderate run if I really wanted. I don't but just because time is limited for me.

I am fairly new to understanding and intergrating the physiologic / metabolic soup that you talk about. So forgive my naive approach thus far and the fairly simple questions that I ask.

First, does your supposition that doing both exercises in the same setting (less than 8 hours apart) assume that one wants to "bulk up" by weight training? I personally started lifting a month ago and have used it more for tone and cardio than to add mass. I don't see any problem with adding it to the elliptical or swim. In fact, those exercises warm the muscles up and get me going. If I do the elliptical I do arm work with weights. I make sure to eat a good meal mixture of complex and some simple carbs and protein at least 2 hours prior to my extended workout replentishing stores.

To the best of my knowledge, in weekend warriors like me (not really, I work out 5 days a week) I understand our glycogen stores in the liver to be about 100 grams. We use about 1 gram a minute and therefore have about 90 minutes before we exhaust our liver stores and start grabbing glycogen from muscle (stores there about 280 grams in non-elite atheletes). My intense work-outs (weights cardio and swim/elliptical cardio) are about 45 min for each exercise (ie 90 minutes total). I then replace protein within 30 minutes of completing the exercise with a mixture of carbs/protein in liquid form (easiest when at the gym and not headed home to eat right away). Skipping the arguement over whether a mixture of complex proteins/carbs mixed with some simple fast absorbing is best in various ratios....for the non-elite athelete...one would think this is probably enough. If I were training for the Olympics and in that kind of shape, the story might be different...and the whole story does change depending on the type of exercise (swim, row, run) and effort etc. Elite atheletes actually reportedly carry less stores in the liver and run around with an average of 55 grams in the liver at baseline (not the 100 grams in my liver). By carb loading they can increase muscle stores up to 800 grams (mine are probably stuck at 280). So for them, they can store even more and go harder longer. All this is to say that I do believe while the arguement of not combining exercises of resistance and cardio on the same day apply to some, it probably doesn't apply to all. Just depends on what you want out of it and how long you do it and how hard you are doing it. Yes? or am I down a creek without a paddle?

Lastly, why is it that we say cardio exercises don't build muscle? or need a positive testosterone balance to improve muscle synthesis and slow breakdown? Bikers have big quads and hamstrings. Aren't they building muscle too?

Just asking....as I said....this is all new to me...I've been reading for a week or two and realize I know enough to be dangerous. So educate and convince me.

All good questions tex, I'll see if I can respond in kind.

to your first question, it does assume you are looking to gain or maintain muscle mass by targeting muscles for specific weight training. I.E. testosterone release happens only in certain conditions (over and above the normal levels in the body that is), and moderate cardio, or even most HIIT training routines don't trigger high releases of testosterone, mainly because the body will only release hormones when the muscles "request" the need for more power. It's actually a complex set of hormonal releases based on charge balance and chemical homeostasis. I.E. glycogen depletion doesn't cause the testosterone trigger to happen, only using muscles to their maximal effort for an extended period will do this. As the body perceives failure because of mechanical work will it release testosterone, not because of energy depletion.

your understanding of localized and liver glycogen stores is actually very close to right on, the only thing you should be aware of is that muscle glycogen is not mobile, in other words the 250 to 350 grams in most adult males at the muscle site is locked at the muscle site, thus is not available to other muscles. Only the liver glycogen will be released to replenish muscle use, and the liver will always hold some glycogen in reserve for the brain if it can, it's almost impossible to completely deplete the liver of glycogen, thus about 80 grams can be released, and that takes 5 to 15 minutes to replenish a fully depleted muscle, that's why when you're looking for hypertrophy, your rest times between sets should be about 3 to 5 minutes, we're looking for mechanical work failure, not glycogen depletion.


to your last question about whether cardio builds muscle. It just doesn't, there's hundreds of studies documenting this, I'm not going to go listing them, but they're easy to find if you go to ajcn.org and search for cardio and muscle mass gains. But to be more to the point, and easier to understand, cardio works below the aerobic threshold, never triggering the response needed to build new muscle mass, unless the person never uses or uses very infrequently, the muscles being used for cardio, the body won't trigger mass (power) gains. Remember, the body is an efficiency engine, it will only add extra muscle when it perceives a need. If the need (like when doing cardio) is for better oxygen efficiency and OSAT (oxygen saturation in the blood) then the body will increase lung capacity, and mitochondrial counts to account for this, the one exception to this is the heart, and smooth muscles around the arterial systems which can grow stronger with cardio. But I'm sure we've all heard the stories of highly trained athletes that have extremely low resting heart rates, it's because their bodies are both adapted to better extract oxygen out of the blood, and their hearts are stronger, pumping more blood volume during each stroke (thus needing less beats to deliver the same amount of oxygen).

My point is basically this:

It isn't an all or nothing game, you can do both, and you'll probably return about 70% to 80% of the results that you would from each if compared to if you did them separately. Which, for many people is fine. It does make it easier if you're in a time crunch.
BUT
A lot of people ask me whether you should do both, 1 first, or the other first. And I always give them the answer of: "if time is an issue, then do both, but don't expect optimal results from either". And I say that simply because when you get right down to it, if you're training to gain strength, then your body needs fuel to recover, if you do that AND do cardio, you're depleting your energy levels, muscle repair waits for nobody, and if you have no energy to fuel your recovering body, then the protein and amino acids that would normally go towards building or repairing muscle tissue will instead be used to supplement energy recovery as the body deems that more vital to short term survival than building new muscle later (I.E. run away from the saber toothed cat, THEN worry about being strong enough to kill it next time)

The study I noted in my original quote wasn't elite athletes, they were adult males that were in good shape, but not elite, the process is similar for everyone. It's as much about balance as it is about anything. If you're looking for specific gains (I.E. strength and size gains, then the focus should be on hypertrophy and power, if your looking for overall endurance gains then the focus should be on sub-maximal cardiovascular work, if your focus is to gain endurance at one specific muscle site then the focus should be on HIIT training with specificity.

You mentioned cyclists, and that's true, but what we don't see is that the off season training regimen of most professional athletes has just as many strength days as it does specific sport training days. I.E. bicyclists do squats on some days, but they very rarely will do squats immediately followed by a long cardio session, the may do it in the same day, but always separated by hours and a re-feeding to replenish. The other thing to remember about professionals is that their bodies are trained to a point where they are supremely efficient at recovery, so what may take you and I 8 hours may only take them 3 or 4, that's more individual, but it's still a factor.

hope this helps clear some stuff up.

Let me know if you have any more questions.

I agree, but studies aside, it makes sense to me that if you are working hard enough at one, you should not have any energy for the other.

I keep seeing diaries where someone will do 45 minutes of strength followed by an hour of cardio. Neither is being done effectively. 45 mins of strength training should leave someone wanting to take a nap, not take a zumba class.