Cardio before or after strength training?

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Kracht of cardio

Do you do cardio before or after strength training? It doesn’t matter for the effectiveness of both types of training. That’s at least the outcome of a recently published study in the Journal of Strength & Conditioning Research. However, other studies show results indicating that the order does indeed influence the outcome. You can read exactly how that works in this article.

Table of contents

• Strength or cardio
• “Cardio before or after strength training makes no difference”
• Results
• Determining order based on primary objective
• Strength training and cardio combined
• Burning fat in the short term or long term?
• Effect on fat burning depends on rest between both workouts.
• Conclusion cardio before or after strength training
• “Traditional order”: Cardio after strength training
• Cardio after strength training at the expense of muscle mass?
• Glycogen depletion
• Cardio after strength training limits improvement in strength and muscle mass
• So first strength training and then cardio?

The “traditional” instruction that fitness professionals generally give to clients who have both cardio and strength training on the schedule is to do strength training first and then cardio. When I was studying to become a fitness instructor, this was also the standard order in every training schedule that included both strength training and cardio.

Typically, the order was:

Warming-up, strength training, cardio, cooling down, and optionally stretching.

The explanation given here is that the energy expenditure during cardio should not detract from strength training.

“Cardio before or after strength training makes no difference”

Recently, researchers from Rutgers University in New Jersey wanted to test the validity of this statement (1). They divided 23 untrained female students into two groups.

13 students would do cardio first and then strength training, while the remaining 10 would follow the reverse order. The training program lasted eight weeks. Cardio consisted of four times per week for 30 minutes at an intensity of 70%-80% of maximum heart rate (220 – age). Heart rate and fatigue experienced by the participants were recorded, and based on these values, the intensity was increased each week.

Strength training consisted of a three-day split (chest + back, shoulder + arms, and lower body) with 5 to 6 exercises done for 3 sets of 8-12 repetitions at an intensity of 90%-100% 10RM.

(10RM is the maximum weight one can lift for 10 repetitions).

The weight used for training was recorded. Once 12 repetitions could be done with it, the weight was increased.

As a training result, they measured the effect of the two different orders on VO2max (maximum amount of oxygen your lungs can take in), muscle strength, and body composition (lean mass vs. body fat). These were measured before and after the eight weeks to assess the effects.

*The research text refers to “endurance.” This can be referred to as “cardio.”

Results

VO2max: Endurance improved in both groups during the eight weeks, but there was no significant difference between them. In the group that did strength training first, the increase was slightly larger, but not large enough to suggest that this difference was not caused by chance.

Muscle strength: The difference in 10RM was examined during the leg press and chest press. Progress was made in both, but again, there was no significant difference. Strength increased slightly more in the group that did cardio first on the chest press, and it was the opposite on the leg press. However, in both cases, the difference was not significant enough to be attributed to chance.

Body composition: Finally, the ratio between lean body mass and body fat was examined. In both groups, lean mass increased. In the group that did cardio first, the increase was 0.3 kg. In the other group, it was 0.6 kg. Both were significant increases compared to the start of the 8 weeks, but again, this difference was not statistically significant. Total body weight increased in both groups, but the body fat percentage remained the same.

The researchers therefore conclude:

Based on the results of this study, it can therefore be advised to recommend a concurrent and combined exercise program consisting of E and R, regardless of sequential ordering, towards the improvement of one’s health and fitness in an inactive female population.

P.M. David, Rutgers University

As mentioned, there are studies that do indeed see different results when doing cardio before or after strength training.

Determining order based on primary objective

Which order is most effective seems to depend on your primary objective. Someone who does cardio before or after strength training may have various objectives: building muscle mass, muscle strength, improving endurance, or burning fat.

The order can have different effects on these various objectives, so it cannot be generally stated that one order is better than the other. In fact, according to some studies, depending on your primary goal, the combination should not be done at all, regardless of the order.

Personally, I am a follower of this latter school. My primary goal is to build muscle mass. As an ectomorph, fat burning has a very low priority for me. So for me, it is wise to consult the studies to see if a combination is really detrimental to muscle mass and whether the order matters. However, if improving endurance or fat burning is your main goal, you should consult the research on this.

Furthermore, the study above tested untrained women. Other studies show that it may be different for trained individuals. So you should also consider your own training experience.

Combining Strength Training and Cardio

If your primary goal is improving endurance, then according to researchers from the Faculté des Sciences de Tunis, it is advisable to do cardio before strength training (2). They found that when a 4-kilometer run was done after this sequence, it was more successful than when only cardio or strength training was done beforehand or when strength training was done first and then cardio instead of the reverse. When doing strength training first and then cardio, the researchers observed that VO2max, maximum oxygen uptake, increased significantly more than in the other cases.

Circuit training immediately after individualised endurance training in the same session (E+S) produced greater improvement in the 4 km time trial and aerobic capacity than the opposite order or each of the training programmes performed separately.

M. Chtara, Faculté des Sciences de Tunis

Researchers from the University of Kansas only looked at the order of strength training – cardio and, based on the results, recommended not doing strength training beforehand (3). They divided 30 young, active men into three groups. One group did cardio, the second group did only strength training, and the third group did both with strength training done first. They found that in both the group that only did cardio and the group that did both, endurance increased. However, in the group that only did endurance training, the increase was significantly greater. So, combining strength training with endurance training came at the expense of the effects on endurance and fat burning.

These data indicate that, although resistance training (krachttraining) alone will increase BMR (Basal Metabolic Rate) and muscular strength, and endurance training alone will increase aerobic power and decrease body fat, combined training will provide all of these benefits but to a lesser magnitude than RT and ET after 10 wk of training.

B.A. Dolezal, University of Kansas

According to these researchers, the combination of strength training and cardio (in that order!) will yield the benefits of both but to a lesser extent than when they are trained separately.

Burning fat in the short term or long term?

They found that the amount of body fat and the percentage of fat decreased more after doing only cardio than with the combination with strength training (or with only strength training). So, in the short term, only cardio had a greater effect.

However, when looking at the BMR, the Basal Metabolic Rate, it was a different story.

BMR is an indication of your energy expenditure at rest. The higher it is, the more calories your body needs. You will then lose more weight or gain less with a constant diet. BMR increased when strength training was done (alone and in combination with cardio), but not when only cardio was done. In the latter case, it actually decreased, meaning you would have to eat less to achieve the same result from the same cardio.

So, it remains to be seen what would happen if the study were to last longer.

Effect of fat burning depends on rest between both workouts.

However, if you read the previous study, it mentions that both strength training and cardio were done on the same day. This says very little about the combination since there could have been hours between them. In practice, these workouts are almost always done back to back. With the exception of professional athletes, there are few people who go to the gym twice a day.

Research from Japan shows that there is a big difference between a short break or a long break between both workouts. Researchers from the University of Tokyo had the participants in their similar study do the combined training (strength then cardio) twice. The first time this was done with 20 minutes of rest between both workouts and the second time with 2 hours of rest in between. The Japanese found that it was precisely strength training before cardio that increased fat burning instead of decreasing it as was the case in the previous study. However, the Japanese only saw this effect with 20 minutes of rest and no longer when there was a two-hour break between both workouts.

They suspected that during strength training, additional hormones, such as adrenaline, noradrenaline, and growth hormone, are released, causing more free fatty acids to enter the bloodstream, which are then burned as a source of energy during cardio.

These levels were still elevated 20 minutes after strength training, but then quickly decreased to lower values than before.

This has to do with negative feedback.

The body sees an increased level of released hormones and lowers production to stabilize it. Two hours after strength training, these levels were lower than in the control group that had not done strength training first, resulting in a negative effect on fat burning. The researchers did not look at BMR and long-term effects. So, it is unclear which method would yield the best results in terms of body fat percentage after, for example, 3 months.

After reading this study, I went back to the first recently published study from Rutgers University that was the reason for this article.

It turned out that doing cardio before or after strength training does not make a difference in body composition and therefore body fat. I hoped to read that they had taken too long a break between the workouts as an explanation for the contradictory results of both studies. However, the rest in this study was only 5 minutes and therefore comes closest to reality. So, what’s the explanation then?

The researchers from Rutgers University did not compare the combination of strength and cardio with cardio alone. They compared two orders between them:

First cardio or first strength training.

If you conclude that strength training alone can have a positive effect on fat burning during cardio afterwards and not vice versa, then the outcome from New Jersey would indeed contradict the research from Japan. However, there is a study that has shown that the combination of cardio-cardio (yes, you read that right) also results in more fat being burned during the second workout (7). So, it is quite possible that in the study from New Jersey, two positive combinations were compared, both of which are better for fat burning than separately. However, this was not seen because they were only compared to each other.

As far as fat burning is concerned, I am not aware of any studies that show that a combination of strength training and cardio, in any order, has a negative impact on fat burning. At worst, there is no added value.

Conclusion cardio before or after strength training

To determine whether it is advisable to do cardio before or after strength training, it is useful to first determine your priority. Research into this shows that the combination of both does offer the benefits of both separate workouts, but depending on the study, this may be to a lesser or greater extent.

Regarding endurance as the main goal, there is one study that looked at the combination of cardio before strength training (in that order) and found that maximal oxygen uptake increased more with a subsequent endurance run than with the reverse order or separate workouts.

If fat burning is your main goal, then it seems that strength training before or after does not have a negative effect. One study shows that you burn more fat by doing strength training before cardio, provided that the rest between both workouts is not too long.

In this part of this article, I discussed the debate about whether or not to combine strength training and cardio and in which order this should be done. To assess this, it is important to first determine which goal you prioritize.

I mainly looked at the consequences when improving endurance and fat burning are your main objectives. I referred to a recent study that addressed this and discussed (parts of) studies that specifically looked at the effect of the combination and various orders of this on endurance, stamina, and fat burning.

Below, I specifically look at the effect on muscle strength and muscle mass under these different circumstances.

“Traditional order”: Cardio after strength training

In the section above, I briefly explained that in a “traditional” training schedule as many fitness professionals will set up, strength training is followed by cardio. This is partly due to the idea that you first train at a higher intensity where your glycogen stores are tapped into. This is the stored form of ingested carbohydrates. The articles on energy systems go into more detail on this and on the different energy suppliers per degree of intensity and duration of exertion:

The simple idea is that if you use strength training first, you can fully utilize the glycogen stores. The cardio that follows is of lower intensity and uses the aerobic energy system where both glycogen and fats are used to provide energy (via ATP). Firstly, the need for glycogen during cardio is therefore lower than during strength training. Moreover, due to the already depleted glycogen stores, it can be expected that during cardio, fats will be used as fuel sooner and more.

Cardio after strength training at the expense of muscle mass?

My personal focus is purely on building muscle mass. As an ectomorph, I am naturally very lean, I don’t need to do or avoid anything for a six-pack, but I do have to continuously make an effort to maintain and increase muscle mass. The above explanation of the traditional order is nice if you want to both build muscle mass and burn fat, but in theory, it may mean that you do not achieve the full result in terms of muscle mass.

As mentioned, during intensive strength training, you use glycogen, the stored form of carbohydrates. This supply can only be replenished to a limited extent beforehand. I have previously referred to research showing that at maximum intensity, glycogen stores are depleted after 30 to 40 minutes (1). During strength training, you have rest in between, which could make this last a little longer. Depending on the intensity and duration of the training, you would expect that an average strength training session would take a little longer.

After this, however, when glycogen is depleted, your body goes in search of energy. Even when you rest after this, your body needs energy for essential functions such as those of the brain and heart. This also happens using the aforementioned aerobic energy system.

The problem here is that not only glycogen and fats are used, but also amino acids. These amino acids come from protein broken down in the muscles. You can prevent or limit this by taking in fast carbohydrates immediately after training so that after conversion of these, the body has glycogen again (although some believe that this immediately reduces the growth hormone levels that have increased due to training). Another solution is to use the fastest possible protein immediately after training. I use hydrolysates for this (whey or casein as in Pepto-Pro). This ensures rapid delivery of available amino acids into the bloodstream, reducing the need to tap into protein in the muscles for this purpose. Moreover, the body thus has the necessary amino acids to rebuild protein in the muscles.

If you do cardio after depleting glycogen during strength training, you increase the need for energy and it takes longer to prevent breakdown by ingesting carbohydrates or protein.

That is at least my personal reason for not doing cardio after strength training in order to focus everything on muscle mass.

Glycogen depletion

Therefore, let’s first look at the extent to which the above applies in terms of depleting glycogen during strength training.

Two studies have been conducted in which bodybuilders did half an hour of strength training. In this half hour, they did front squats, back squats, leg presses, and leg extensions. They did 5 sets of each exercise to failure, as many repetitions as they could, which amounted to 6-12 repetitions. So, you would think that the quite exhaustive training would deplete a large part of the glycogen supply. In the 1986 study, they took a biopsy of the vastus lateralis (outer thigh) after training to measure the concentration of glycogen (2). This turned out to have decreased by only 26%.

Muscle glycogen concentration was 26% lower post-exercise, a rather modest decline considering the demanding exercise protocol completed. This led the authors to conclude that energy sources in addition to muscle glycogen support heavy resistance training.
P.A. Tesch, Mid Sweden University

So, besides glycogen, there must be another supplier of energy. When the study was repeated four years later, the researchers also looked at the amount of triglycerides (fats) in the muscles (3). In addition to a decrease of 28% in glycogen, similar to the earlier study, they observed a decrease of 30% in triglycerides in the muscles.

This suggests that intramuscular lipolysis (breakdown of triglycerides) may also play a role in energy production during repeated high-intensity exercise. Overall, research suggests that intramuscular glycogen is an important fuel supporting weight training exercise, but not the only substrate.
B. Essen-Gustavsson, Swedish University of Agricultural Sciences

In a study from 1991, researchers had their participants do 6 sets on the leg press (4). Once on average 13 repetitions at 35% of their 1RM (the maximum weight with which they can do one repetition) and the second time an average of 6 repetitions at 70%. Surprisingly, both resulted in a similar depletion of glycogen, 38% and 39% respectively. Surprising because the difference between them is so small, but also because more glycogen was used than in the previous two studies while fewer exercises were done.

What makes this last study interesting is that the researchers also looked at how quickly the glycogen supply was replenished after training without taking in food. This replenishment of glycogen provides an indication of the extent to which fats and protein (from muscle mass) are converted to generate new glycogen (glycogenesis).

Within two hours, the glycogen stores had already increased by over 22%. Lactic acid also plays a role in this as a precursor to glycogen, but this role turned out to be very limited.

So, the glycogen store doesn’t have to be empty before the body starts using resources to replenish it. Imagine doing cardio during this time; the body will have to use even more resources for this, which can come at the expense of the muscle mass you’ve just trained so hard for.

Cardio after strength training limits improvement in strength and muscle mass

Looking at muscle strength, we see this reflected in the study from the University of Kansas that I mentioned in Part I. In the same study, the researchers found that both strength training combined with cardio and cardio training alone resulted in an increase in strength (5). However, when only strength training was done, this increase was significantly greater.

These findings demonstrate that simultaneously training for S and E will result in a reduced capacity to develop strength, but will not affect the magnitude of increase in VO2max.*
*(S=Strength, E=Endurance -red)

This was also evident in 1980 when researchers had three groups train (6). These did: Strength training only, endurance training only, or a combination of both. While they found that the combination provided the same benefits for endurance (in terms of VO2max), the combination did not yield the same result for strength as when only strength training was done.

These findings demonstrate that simultaneously training for S and E will result in a reduced capacity to develop strength, but will not affect the magnitude of increase in VO2max.*
*(S=Strength, E=Endurance -red)

Researchers from Pennsylvania State University had their participants train under different conditions: strength and cardio, upper body strength and cardio, high-intensity cardio, or strength training alone (6).

When they then looked at the development of the various muscle fibers, they saw that the various trainings, whether combined or not, resulted in different adaptations of the various muscle fibers. They saw a shift in all groups from fast-twitch type IIb to IIa.

In a previous article, I described the “switching between twitches”, which entails the existence of various muscle fibers for low intensity, high intensity, and explosive power. The latter two are the fast twitch fibers, or fast twitch fibers, IIa (“fast”) and IIb (“superfast”). If you train a lot on explosiveness, some IIa fibers will change into IIb. If you focus more on strength and mass (slightly less weight and more repetitions than maximal strength and explosive power), the opposite happens.

So, for muscle mass, you would ideally like to see the IIb fibers change into IIa. This latter occurred in the study in all cases, but most when only strength training was done. Moreover, they observed the greatest increase in strength when only strength training was performed.

Our data indicate that single-mode training tends to be the most effective for strength or endurance performance and its concomitant muscle fiber changes. Similar to other studies in the literature, the exercise

W.J. Kramer, Pennsylvania State University

Recent research from Brazil looked at the development of strength in older men (average age 65) after doing strength training, strength training and cardio, or just cardio. In both the group that did only strength training and the group that did the combination of strength training and cardio, strength increased. However, in the group that only did strength training, this increase was 67% compared to 41% in the group that did the combination.

Finally, a study from Australia that appeared a year earlier. In this study, strength training, strength+cardio, and cardio alone were also performed. The researchers looked, among other things, at the effect on body composition. In both the group that only did strength training and the group that did the combination, the fat-free mass increased. However, this increase was greater in the group that only did strength training (3.6% compared to 2.4%).

So strength training first and then cardio?

In part I of this article, it was found that if your main goal is to improve your fitness, it is unclear whether combined training is advisable due to the different outcomes of the studies on this. The benefits for fitness are achieved during the combination of strength training and cardio (in that order), but according to some studies, to a lesser extent than when cardio was done separately or even cardio prior to strength training.

As for fat burning, the combination seems to have no adverse effects. The combination may even increase fat burning, provided the break between both workouts is not too long.

However, if strength and muscle mass are the main objectives, then it is clear (given the unanimous outcomes of various studies on this) that the combination of strength training followed by cardio in one workout produces good results, but not as good as when only strength training is done.

Unless strength and muscle mass are a clear priority, it is advisable to combine both strength and cardio in one training session to benefit from the advantages of both.

References

1. Van Loon LJC. The effects of exercise and nutrition on muscle fuel selection. Maastricht: Universitaire Pers Maastricht, 2001.
2. Tesch, P. A., Colliander, E. B., & Kaiser, P. 1986. Muscle metabolism during intense, heavy- resistance exercise. European Journal of Applied Physiology, 55, 362-6.
3. Essen-Gustavsson, B. & Tesch, P. A. 1990. Glycogen and triglyceride utilization in relation to muscle metabolic characteristics in men performing heavy-resistance exercise. European Journal of Applied Physiology, 61, 5-10.
4. Robergs, R. A., Pearson, D. R., Costil, D. L., Fink, D. D., Pascoe, M. A., Benedict, C. P., Lambert, C. P., and Zachweija, J. J. (1991). Muscle glycogenolysis during differing intensities of weight-resistance exercise. Journal of Applied Physiology, 70, 1700-1706.
5. Dolezal BA and Potteiger JA. Concurrent resistance and endurance training influence basal metabolic rate in nondieting individuals. J App Physiol 85: 695-700, 1998.
6. Hickson RC. Interference of strength development by simultaneously training for strength and endurance. Eur J App Physiol 45: 255-263, 1980.
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8. Cadore EL, Pinto RS, Lhullier FL, Correa CS, Alberton CL, Pinto SS, Almeida AP, Tartaruga MP, Silva EM, and Kruel LF. Physiological effects of concurrent training in elderly men. Int J Sports Med 31: 689-697, 2010.
9. Ghahramanloo E, Midgley AW, and Bentley DJ. The effect of concurrent training on blood lipid profile and anthropometrical characteristics of previously untrained men. J Phys Act Health 6: 760-766, 2009.