"So, do you want a workout that feels effective or a workout that is effective?" It's an internal monologue that I've had while working with many new clients throughout the years, one that I am generally better off not saying so bluntly aloud. Enthusiastic go-getters who just started training or who have been training for a while want a workout that challenges them. They want something that feels hard, is hard, and really gets them going. They want to sweat, they want to breathe heavy, and they want to get their heart rate up.
Sometimes, when working with such people, I need to temper their expectations. We need to work to make sure that we are getting an effective workout, not just a workout that feels like it is hard.
Consider this: if I really wanted to give you a workout that would feel hard and get you out of breath, what would that look like? Well, that would be very easy, wouldn't it. Step 1: run as fast as you can until you are out of breath. Ste 2: do jumping jacks until you can't do jumping jacks anymore. Step 3: do push-ups until you collapse on the ground. Repeat until you are exhausted. Presto! A hard workout.
But is this type of training actually effective? Is the perceived difficulty of a workout what makes it work? And are harder workouts better? Let's find out.
Training to failure versus adequate volume.
I don't mean to bury the lead here by giving you the answer right out of the gate, but training to failure and a non-failure training have been shown to yield the same results. This has been studied extensively (1).
Another thing that we also know is that acute spikes in workload lead to an increased risk injury (2). We also know that "acute spikes in workload" does not JUST mean the actual weight you are lifting, reps you perform, and number of sets you do. This can also refer to the RPE, or rating of perceived exertion of the weight that you are lifting (3).
I'm sure we've all had bad exercise days. Those days where we get to the gym, and no matter how hard we try, our performance just sucks. During these days, a weight or number of reps that may normally feel fairly easy may become bone crushingly difficult.
However, there are other days when we step into the gym and we just feel great. We can do anything, the world is our oyster, and the sky is the limit. On these days, a personal best may not even feel particularly heavy. Enter: the concepts of internal & external load.
Internal load is not just the amount of work you are doing, but the amount of work you are doing after it is filtered through all of the variables that affect you mentally, emotionally, and physiologically. These include work stress, life stress, injuries, fatigue, soreness, tiredness, lack of sleep, and pretty much anything that can impact your training performance that isn't a hard, measurable variable (4).
External load is the actual hard numbers. Weight that you are lifting, number of sets you perform, reps per set, etc. Essentially, anything we can measure outside of your body is the external load of training.
Your internal load is more closely associated with injury risk than external load (3). Therefore, if you push really hard, often going to failure in training, it likely increases your risk of injury. There is no higher internal load than going to failure.
I would not suggest going to failure often. The fatigue demand of failure is high, and the likelihood of hurting yourself is increased. Additionally, the results of doing so are not superior for muscle growth or strength gains.
Rest time between sets.
What about resting between sets? Having shorter rest times makes your workout feel harder, but does it actually make it more effective? Well, fortunately for us, we have data on this too. A 2009 literature review by Belmiro and colleagues looked at all of the current data on rest time between sets. This review found that longer rest times of 3-5 minutes between sets produce superior strength gains. Rest times of longer durations also led to increased power versus shorter rest time (5).
One reason in particular why this literature review is of note: it looked at over 35 studies and drew conclusions from the preponderance of the evidence. It is not just one study looking at a small group. It is many studies examined closely to identify common threads among the data (5).
Additionally, Brad Schoenfeld has done a good amount of research on this topic. A 2016 study compared 1 minute rest intervals to 3 minute rest intervals in resistance trained young men. The study found that 3 minute rest intervals yielded significantly greater hypertrophy gains (7).
Why do longer rest times produce superior strength, power, and muscle? One reason is because the longer you rest between sets, the more weight you are able to lift on subsequent sets. Also, the more reps you will be able to do before fatigue, the more hypertrophy you will incur. The relationship between total training volume (sets x reps x weight) and hypertrophy is well documented (7). Those who perform more sets, more reps, and lift heavier weight, see superior muscle growth.
What about for weight loss? Do you want a workout that feels hard if your main goal is losing weight? Probably not. In fact, the opposite is likely true.
A 2010 study found that in formerly overweight women, high perceived difficulty of their exercise program was actually correlated with weight regain one year after the program was completed. Further, it is concluded by the study that a high difficulty exercise program is likely related to falling off and not continuing with healthy behavior changes long-term (8).
There is a lot of data to support the idea that exercise programs that are too difficult are not the best option for weight loss. Physical activity is one of the master keys to keeping weight off (9), so we need to create programs that are not only effective, but also not too high in terms of difficulty.
Exercise alone is not the only key to losing weight. In fact, dietary changes alone have been shown to be more than three times as effective as exercise alone for weight loss (10). Further, the best option is obviously both diet and exercise, which has over four times the effect of just exercise. These numbers and others would lead us to believe that while exercise plays a role in weight loss, having a highly difficult exercise program is not going to help you lose any more weight, and it is likely to impede your ability to maintain lost weight long-term. Further, it may also create additional barriers towards maintaining physical activity habits that you are trying to build in order to live a healthier lifestyle.
Getting out of breath versus having an effective workout.
What about cardio? I mean shouldn't my cardio workout be really hard? Shouldn't I be sweating and hardly able to breathe by the end of it? The more calories I burn, the better, right? Maybe not.
Different intensities of cardio have been found to have a similar effect on weight loss (11, 12). This means it doesn't matter if you run, jog, or walk - all are equally effective for weight loss. However, it is a little more nuanced than that. There are both pros and cons to implementing high intensity exercise in a weight loss regimen.
High intensity interval training, of HIIT, has been shown to be more efficient on a per minute basis. This means that you can burn more calories, and perhaps incur slightly more weight loss on a minute per minute basis with high intensity cardiovascular exercise than with low or moderate intensity cardiovascular exercise (13). High intensity cardiovascular exercise also seems to produce greater increases in aerobic fitness.
However, as previously noted, the prescription of high intensity exercise has a marked decrease in adherence. Those who perform high intensity versus moderate or low intensity tend to like it less, and tend to follow through for a shorter period of time (14).
In my opinion, the takeaway is this. On average, higher intensity cardio is going to not be as effective for long-term weight loss and maintenance of habits. However, for people with limited time, or those who have interest in pursuing performance related goals, HIIT has its place. For those with low self-efficacy, a history of struggling to maintain exercise habits, and / or low familiarity with effective training protocols, low or medium intensity cardio is likely more effective.
Progressive Overload & Fun.
The final piece of the puzzle I want to talk about is progressive overload. Progressive overload is the process of adding more sets, reps, intensity, exercise variations, and other variables over time to increase the total amount of work performed during a workout. As previously stated, increasing training volume is highly correlated with muscle growth.
However, having a sense of fun and accomplishment baked into your training program may be the key toward long-term success (15). People who succeed in performance goals, and have a high degree of involvement in their training programs tend to fare better. Further, having tracking methods to quantify success are important for many people (16).
The reason why I bring this up is because we want to train in a way that facilitates progression. People will stay engaged longer, therefore getting better results if they enjoy what they are doing and are making progress. Sure, training to failure may get you slightly better results in the very short term, but at what cost?
Honestly, anyone can string together a random assortment of exercises and make the workout "hard". But it takes a good understanding of exercise programming, fatigue management, experience actually working with people, and knowledge on implementing individualization in a training program, to make a workout that is effective for the long haul.
My advice, and final word: make training fun. Take your time. And maybe, just maybe, if you're one of those people who always needs a hard workout to feel like you've accomplished something, perhaps just tone it down a little bit and look at the many ways that a well formulated and maybe not so difficult to training program could benefit you.
I'm speaking directly to you, the overachiever. I know being hyper competitive and always working as hard as possible may give success in some endeavors in life, but when it comes to fitness, more is not always more.
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