When selecting the goals for your workout program, typically the best thing you can do is choose one goal to primarily focus on. This is what will best enable you to narrow down your focus so you can get ideal results from your training and diet program. Just like anything else in life, the more focused you are towards a single goal, the more time and energy you will be able to devote to it. When you have a broken focus, or are trying to spread yourself too widely, that’s when you’re going to find that you’re not really getting anywhere because you spend too much time going between goals, trying to accomplish a number of things at once.
When talking in the fitness sense, the most common application of this that you’ll see is individuals who want to train for endurance related activities, while also focusing on muscle building. Whether you are looking to train for a half or full marathon, a triathlon, or you are simply involved in a sport that has a lot of running and find yourself regularly going for 45+ minute long runs, you have to ask yourself how big of an impact this is going to have on your ability to gain muscle.
Here’s what to consider.
Metabolic and Food Intake Issues
The first thing to think about is the impact of endurance training on the metabolism and food intake. When doing moderate paced aerobic endurance work, the body is going to primarily rely on fat as fuel, which is actually a good thing as far as your ability to build muscle is concerned. Because of the fact you won’t be depleting all your muscle glycogen stores during the run, this will help save these stores for when you really need them – while trying to build muscle.
If you were to begin doing a lot of interval type of training within your endurance program though then that would become a larger issue because the body then will be using those stores up much more quickly. Now, the bigger issue at hand here with regards to this factor is the increase in food intake that will be required. If you’re a male who already has a somewhat faster metabolic rate, you’re likely going to have a hard enough time getting in the necessary calories to build muscle without adding a whole lot of additional exercise to your schedule. If you are out burning off 400-700 calories per endurance workout, those calories must be eaten back if you are hoping to maintain a caloric surplus that is required for building new muscle mass.
For example, if your maintenance calorie intake is 2500 calories (an average 170 pound male), and then you add 500 calories to this in order to promote muscle building (bringing you to the 3000 range), and then you have to add another 700 calories for your hour long endurance session, you’re not close to 4000 calories a day, which is going to be a hard number to get to for many people. On top of that, if you’re someone who tends to have a naturally fast metabolism, this may be underestimating your calorie needs to start with, therefore you’ll have to go even higher if you hope to see progress happening.
Moving on, another issue that’s going to come up once you start doing a great deal of endurance training is the hormonal aspects at play. Essentially, endurance training will put the body in a completely different hormonal environment than resistance training will. Resistance training will cause the body to become anabolic (tissue generation – assuming enough rest is given), while endurance training will tend towards the catabolic side, essentially cause tissues to be broken down by the body. Due to this fact, the simple act of endurance training alone on the body will prohibit you from generating a maximum amount of muscle. While you may still be able to build some muscle depending on your food intake and overall program set-up, you won’t be building muscle optimally.
More specifically in terms of the hormones involved, a high level of endurance training will cause the body to secret the hormone known as cortisol, which primarily will limit anabolic processes going on. Cortisol is the stress hormone that’s secreted by the body when you are highly stressed as well, and if it’s elevated for longer periods of time, it can cause muscle wasting. Finally, another hormonal issue that’s slightly less of a problem but could still come into play is if your endurance training session are of a higher intensity and cause the blood sugar levels to really drop down. Since insulin is one of the main hormones that is involved in the muscle building process, when blood sugar levels are constantly low, less muscle building will be occurring.
This will come into play more though if you were to do a weight lifting session in the morning say and then move on and do an endurance workout within a couple of hours. You can also counteract these effects with proper nutrition (since a higher carb intake will bring insulin levels up significantly); you just have to make sure it’s something you are monitoring.
Next you have recovery issues involved with endurance training. Since the body can only handle so much at once, if you’re performing a high amount of cardiovascular work, it becomes harder and harder to recovery sufficiently enough for your weight lifting sessions. You can work twice a day workouts into your schedule to help increase the total days off you get to just rest, but then you may find that either your weight lifting or your cardio session performance goes down on the day you are doing both together, depending on which you start out with. Further, since endurance training does place quite a fair amount of stress on the joints (depending on the modality), this could be another issue when combined with heavy weight lifting, which also stresses the joints. The ongoing wear and tear could eventually lead to an injury, which will then have you sidelined for a significant period of time.
Going with the point above, not only is recovery going to be an issue with all this training, but you’ll likely find time becomes an issue as well. It will get difficult trying to schedule in all of your workout sessions, therefore something will have to be dropped lower. If your goal is primarily going to be to build muscle, you will want to be making room for at least three weight sessions a week if doing a full body workout program, or else four sessions a week if doing an upper/lower split.
With that many lifting sessions, obviously you aren’t going to be doing a great deal of really long endurance work, so that will suffer. On the flip side, if you’re doing so much endurance work that you’re only able to fit in two weight workouts a week, that isn’t going to give quite the same stimulation frequency, which generally tends to yield better results (higher frequency training).
Body Preference Issues
As a final note, consider in general which types of bodies lend the best to each type of sport. If you have a look at most endurance athletes such as marathoners, they naturally tend to have a thinner, wiry-looking build. On the flip side, if you look at sprints or those who are involved in more anaerobic types of activities (which weight lifting would be), they are more muscular, lean, and show better overall definition. The issue with endurance training is that the body senses it has to carry this mass over a greater distance and thus begins to try and get rid of tissue that’s slowing it down – muscle mass.
Since muscle mass also consumes more calories at rest, it’s also going to be metabolically costly to support, and when you have such high energy demands through the exercise alone, it’s obvious why there would be an advantage to try and lose some of this mass from the body. So, be sure you keep these factors in mind. It’s not to say you cannot do some endurance aerobic work within your program and still get great muscle building results. If proper nutrition is there, rest is being given to the body to allow for recovery, and you are continually noticing strength gains in the gym, chances are you’re right on track with where you need to be. But, it’s definitely a fine line that when you push too far and are doing a bit too much endurance work, your going to see your muscle building ability start to suffer.