Cardio Question.

How much is too much? I've googled and read a few articles but nothing really tells me anything that is beneficial. Some of the symptoms of too much cardio are just things I experience on a daily basis due to low thyroid function, so I wouldn't be able to tell one way or the other.

On a good day I can do anywhere between 60 - 75 minutes of cardio. On my slower days a minimum of 30-45 minutes. I try to do a bit of cardio every day, weight training 4x a week. My exercise doesn't end there, sometimes there's dance classes, then there's work so I'm concerned that maybe I'm over doing it though I don't really feel like I am. Just wondering if anyone has experienced anything detrimental to their weight loss journey from too much cardio, such as muscle burn / loss etc.

Thanks for reading!

Replies

  • MikePfirrman
    MikePfirrman Posts: 3,307 Member
    Check your HR in the AM. Establish a resting HR before getting out of bed. If it starts to show a pattern of going up, you're working too hard.
  • AnnPT77
    AnnPT77 Posts: 31,724 Member
    In addition to the questions Djproulx asked:

    A. Are you being treated for your thyroid condition? If so, what stage are you at in that treatment (i.e., recently diagnosed X weeks ago, long term and treated to normal TSH/T3/T4 levels, etc.)?

    B. If you're losing weight, how fast have you been losing weight (pounds per week, on average)?
  • soulsparx
    soulsparx Posts: 5 Member
    To answer Djproulx:

    1. I've been keeping this exercise routine for one month and yes my level of activity has increased due to my job where I am on my feet 7 hours a day doing physical activity: lifting, bending, running. To give an idea of how my day is I burn about 1200 calories a day (at work) and get about 15k steps just running back and forth - where as before I was hired I did very little exercise.

    2. My purpose is to increase my fitness level and weight loss, also to help with cardiovascular issues (trying to lower my blood pressure).

    3. I am not following a training plan. I am not sure what recovery weeks are lol, yes quite noobish to all this.

    4. Sleep is alright, I get up a few times a night. Resting heart rate ranges between 60 - 68bpm. Not really much fatigue, in fact once I wake up I have a hard time getting back to sleep but ultimately have a lot of energy during the day.

    5. I've not said anything to my doctor but she has noticed the changes in my diet and my weight so she says "keep it up". I do not have a trainer or coach.



    To answer AnnPT77:

    A. I've had Hashimoto Thyroiditis for 26 years and they prescribed 150mcg of Synthroid medication. As of now my thyroid levels are stable.

    B. As I mentioned above because of my job ... I've been losing on average 2-3 lbs a week.


    My main concern is not hurting muscle mass while I do cardio to shred the fat, and also not to over do it too much but not do too little.
  • AnnPT77
    AnnPT77 Posts: 31,724 Member
    With that loss rate, I'd be concerned that you're under-fueling your cardio, more than simply that you're doing too much cardio. You don't mention your current weight, but unless it's well over 200 pounds, 2-3 pounds a week would be an aggressive loss rate, though it's common for people to see a little faster loss for the first couple of weeks of a new regimen, after which the rate will settle down a bit. But losing weight very fast does increase risk of muscle loss.

    Whether for under-fueling or amount of cardio, there isn't really bright line between too extreme, and just fine. It's more a matter of what increases risk of bad consequences, and what decreases risk. The personal context also matters.

    In terms of how much exercise is too much, it depends on an individual's experience and level of conditioning. Going from no cardio to what you're doing right now, and increasing to that quite quickly, would be too much for quite a few people. Gradually increasing is usually a good plan. It also matters how intense the exercise is, in addition to purely how much wall-clock time one is exercising.

    High levels of exercise (time and/or intensity) create stress - even if it's good stress - and that stress is cumulative with other physical or psychological stress in a person's life, so an amount of exercise that would be too much for someone with an otherwise high-stress life might be OK for someone with a low stress life.

    Things that increase stress include a physically or psychologically demanding job, stress in home life (such as tension in important relationships, financial challenges, extreme caregiving responsibilities), fast weight loss, extreme exercise, under nutrition, external circumstances (like a pandemic, maybe?), poor sleep, etc.

    Having a health condition can make a person more subject to over-exercise symptoms, as can aging (in a relative sense, i.e., some of us become a bit less resilient as we get older). If your thyroid condition is effectively treated (including T3/T4, not just TSH), that should not in itself have major consequences. (I'm severely hypothyroid myself, adequately medicated, and don't perceive any major effect related to sensible cardio levels.)

    If your exercise level is new in the past month, plus you've started a physically demanding new job, plus you're losing weight quite quickly, you say you have some difficulty getting to sleep and wake several times a night . . . I'd maybe start to be concerned about cumulative stress. On the positive side, you say you feel energetic, not fatigued . . . but if you've only been at this a month, there can be a bit of a honeymoon period at first. It varies, but a month or two out can be when some consequences start to be evident in terms of performance or fatigue.

    I agree with Mike that it would be a good idea to track your AM resting heart rate over time, and watch whether it is dropping or rising. (Since you're relatively new to this much cardio, you'd like to see it gradually dropping over a period of time . . . but it will bounce around a bit from day to day regardless.) If the sleep interruptions are new, that might be a negative sign. Fatigue or weakness would be a worrying sign, as would mood issues (moodiness, being quicker to anger or cry, that sort of thing).

    If you're going hard 7 days a week, physical work most days plus daily cardio or weights on top of that, I'd encourage you to take at least one lighter day per week, with minimal or only very mild exercise, for recovery. I'd also encourage you to slow your weight loss rate to something between 0.5% to 1% max of your current weight (lower end of that is better, especially if you have exercise performance or fitness goals). If you're still premenopausal, look at your average weight loss over whole menstrual cycles, comparing the same relative point in two or more different cycles, to establish a weekly average across multiple weeks. Keep your overall nutrition strong, certainly adequate protein and fats, but ideally also plenty of varied, colorful veggies/fruits for micros and fiber. Not cutting calories to an extreme will make it easier to keep nutrition strong, too.

    I wish I had some incisive, specific insight for you, but I don't. Most of us recreationally-active folks may not get all the way to "overtraining" in a strict sense, but can overdo to the point of not getting the progress we'd like in fitness, or to the point of increasing our health risks. After you've been at this for a while (by which I mean years, not weeks, you'll probably get a feel for when you're reaching a risk point, but it's hard to figure it out at first.

    These are just my opinions, from being an active person for a couple of decades, with some coaching education in my sport (rowing), but not an expert, a credentialed trainer, or someone with a relevant higher ed degree, so take with a grain of salt.

    Wishing you good fitness progress, good health, and success with your weight management goals!
  • NorthCascades
    NorthCascades Posts: 10,970 Member
    There's too much as a concept, but there isn't a universal number, there isn't even a number for one person, it changes based on your fitness, how much you're exercising already, and other things.

    Based on how you've been ramping it up, it might be too much at this point for you. As you exercise and get fitter you increase your capacity, but it's slow. @AnnPT77 is right about the role food plays in all this.

    Finally, cardio doesn't really impact muscle mass, except running, which has some kind of "interference" effect. That's an issue (or not) when you're lifting heavy weights getting ready for a competition trying to bulk up. It's not something for everybody else to worry about. You'll lose muscle losing weight, it'll be less for you because you're using them.
  • sijomial
    sijomial Posts: 19,811 Member
    The amount of cardio (and other exercise) you can sustain and recover from would be far higher if you weren't eating so little / losing weight so fast.

    No cardio doesn't burn muscle but an inappropriately large deficit can.

    To improve your fitness you don't only have to push hard enough (combination of volume and intensity) to force adaptation you also need to allow your body to recover from the training stress and eating appropriately is a big part of that, Varying your training load also helps, you can't push hard forever without digging yourself into a hole. Last month was my biggest every cycling volume (47 hours) but I didn't ride every day, I didn't ride long every ride, I didn't push hard every ride, I took a couple of three day breaks.

    "experienced anything detrimental to their weight loss journey from too much cardio, such as muscle burn / loss"
    No not at all because I didn't use exercise to boost my rate of loss, I used it to boost my fitness, strength and my calorie allowance - it's a lot easier for me to create a sensible calorie deficit from a high calorie allowance.

    One of the things I like about MyFitnessPal's eat back exercise calorie approach is that it encourages the attitude that exercise is for fitness and health and not for a limited duration weight loss boost.
  • Djproulx
    Djproulx Posts: 3,084 Member
    OP, you've received very thorough and inciteful responses from several very knowledgeable posters above. I will echo some of the main points, specifically:

    1. You have ramped up exercise recently and may very well be feeling the effects of that change.
    2. Checking your resting heart rate (RHR) each morning is a good practice and will offer clues to how well you are recovering over time.
    2. Given the amount of cardio work you are doing, a weight loss rate of 2-3lbs a week is very aggressive. I'd worry about both fatigue and risk of injury over time. You want to follow a pattern that is sustainable long term. That leads to better outcomes, whether weight loss, fitness increases, as well as general wellbeing and satisfaction from exercise.
    3. Perhaps think of cardio work more as a fitness building tool, as opposed to a primary weight loss device.
    4. If you are burning that many calories, you NEED to fuel your body adequately. Your cardio workouts are not so long that fueling DURING the workout is required, but the cumulative training load (CTL) requires you to eat ENOUGH to RECOVER and be ready for tomorrow's cardio session.

    My comments come from my experience over the last 8 years. Starting in 2013, I spent 18 months losing roughly 45lbs as an adult, and rekindled my interest in endurance sports during that time. Over the last few years I have focused on long distance racing, working with several coaches, including my current triathlon coach. We track my fitness and fatigue each day with a software tool that is synced to my garmin devices. That gives us very specific information on not only my fitness(ATL) but also my fatigue (CTL). As a point of reference, I performed 10h 41m of cardio training this past week. Most of that work was moderate or low intensity.

    Finally, I'll offer the two basic messages I've learned over this time period:
    1) Cardio work builds fitness and fatigue. Diet dictates weight loss over time.
    2) Periodized training is very effective if you want to build fitness over time. (think months, not weeks) That means that you build in regular rest days, as well as recovery weeks, that are reduced load. You body builds fitness during the recovery periods. (sleep time, rest days, etc.)

    Hope this doesn't read as too preachy. Best of luck.



  • Chieflrg
    Chieflrg Posts: 9,097 Member
    Current recommendations are 150 minutes of moderate aerobic activity or 75 minutes of vigorous aerobic activity a week, or a combination of moderate and vigorous activity.

    I wouldn't be concerned about muscle loss if you are resistance training as you state unless you were training high endurance like a marathon with a high caliric deficit or possibly you were consuming a low protien and/or leucine diet.
  • cwolfman13
    cwolfman13 Posts: 41,879 Member
    "Too much" is relative to one's current fitness capacity. A few years ago I was riding 100+ miles per week on my bike and lifting 3x per week on top of being a pretty active person in general...that wasn't to much then because I had built my fitness to that level...it would be too much for me right now as, while relatively fit, I'm nowhere near my previous fitness levels...and frankly don't care to be at the moment given the time commitment to training that it took.

    I would also add that I could...and needed to eat a lot in order to fuel all of my activity and recover properly. Crashing your calories and doing a bunch of exercise on top of that along with an active job is not a very good recipe. The more you move, the more fuel (calories) your body needs.

    In my experience, many if not most instances of "overtraining" that I've encountered are actually consistent under eating for a given activity level which is where you eventually see fatigue set in, drop in performance, and often nagging little injuries that you never feel like you quite get over.

    "Cardio" is also a pretty vague term and encompasses a pretty wide variety of exercises and intensities. Lower intensity exercise is going to require less recovery time than doing a lot of higher intensity and more strenuous work. In general I find a good mix of lower intensity work with some more strenuous work sprinkled in to be good for overall health and wellness. A lot of high intensity/strenuous work with little recovery is really hard on the body and combined with low calories coming in can be a recipe for poo poo....
  • jjpptt2
    jjpptt2 Posts: 5,650 Member
    Just to reiterate... what's "too much" and what isn't is also impacted by your diet/nutrition and sleep, not just "exercise".