Intensity Is Everything: Part 2 - Rest Periods And Failure

Cliff Wilson
Written By: Cliff Wilson
August 22nd, 2011
Updated: June 13th, 2020
69.3K Reads
Natural bodybuilder Cliff Wilson explores the impact of rest periods and training to failure, helping you to train better and maximize your time in the gym.

Workout IntensityHow varying intensity techniques can lead to new muscle.

Read Part 1: Intensity Is Everything: Building New Muscle With Intensity Techniques.

“I think I’m gonna throw up!” My young training client said in a panicked voice as he was gasping for air. He had just finished a brutally hard set of squats. I couldn’t help but laugh because not more than 5 minutes ago he had bet me that he trains legs harder than anyone I’ve ever met. I could tell by the sickly look on his face that he knew had lost that bet.

We were only 4 sets into the workout but we had been working at a blistering pace. On the last set I literally had to drag him to the upright position. “I am not used to taking so little rest between sets and I’ve definitely never taken squats to failure before.” He said. We made it though one more set before he went to the bathroom to revisit his pre-workout meal.

I actually see this happen a lot. New clients always brag to me about how hard they train but once we get into the workout you’d think that it was their first day. It is not always that they do not train intensely on their own but rather they do not vary their training enough. Too many bodybuilders find a training style that they prefer and very rarely stray from it.

The human body is extremely adaptive, and if it is not challenged with new stimulus it will not continue to change. In part one, I discussed the importance of varying the volume and load of your workouts while not overtraining. To put together a plan that constantly challenges you with new forms of high intensity training there are other factors that must also be addressed and controlled.

Rest Periods

Rest periods between sets are something that most bodybuilders rarely change. As with rep ranges and the number of sets used during training, most lifters find what they like best and tend to stay within that comfort zone. Rest periods are yet another tool that can be used to raise the intensity of your training.

The amount of rest taken in between sets is directly related to how much energy will be available to your muscles when the next set begins. It takes about 3 minutes after a set for muscles to recover nearly 100% of ATP (adenosine tri-phosphate) and CP (creatine phosphate), which are the two primary energy sources for a working muscle.

This will allow near maximum weights to be used for nearly every set. This is why strength and power athletes take very long rest periods between sets. Taking long rest periods with heavy loads should be incorporated into every bodybuilder’s routine as this will help with the ultimate goal of progressive overload.

Shorter rest periods between 60-90 seconds, will allow for approximately 85-90% recovery of ATP and CP (1). Short rest periods have been shown to have a greater impact on growth hormone levels than long rest periods. Keeping breaks short works great when training for hypertrophy with moderate to light loads for high reps and more volume. Studies show the most dramatic increases in growth hormone with sets that are at least 10 reps combined with rest periods between 45- 60 seconds. (2)

Shorter rest periods also have the advantage of allowing more volume in a workout with less duration. Growth hormone and testosterone levels peak 60-90 minutes into training and fall quickly thereafter. If exercise continues too far beyond this point hormone levels can fall below normal resting levels and can actually remain lower for a few days. (3, 4)

Workout Intensity

I am not an advocate of looking at the clock with a dead stare until my next set, but too often I see bodybuilders take rest periods that are all over the place. Too much talking and texting is most often the culprit. There is no need to change for Facebook status to “Blasting Bi’s and Tri’s” right in the middle of your workout.

It is not acceptable for football or basketball players to text or talk on the phone during practice, so why should bodybuilding be any different? All of these are distractions that will rob you of your focus and intensity. There is no need to break out the stop watch, but appropriate timing between your sets will require paying attention and focusing on the task at hand. Leave the distractions in the locker room and your training will skyrocket to a new level of intensity.


Although failure is a little different than the other forms of intensity discussed here, I feel it needs to be addressed. When training to the point of momentary muscular failure heavy or light loads can still be used. It is simply continuing a set to the point where another rep cannot be completed with good form without assistance from a spotter. When most people think of really intense training, the first thing that usually comes to mind is lots of sets to failure.

This is why whenever the topic of training intensity is discussed, failure training is often the point of emphasis. Just like the other forms of increasing intensity, training to failure has been a very heated topic in the bodybuilding community for decades. Many advocates of training to failure feel that a set not taken to failure is a wasted set. Detractors of failure training avoid taking any sets to failure for fear that it will lead to overtraining. Both groups have valid concerns that need to be addressed.

The rational for training to failure is that during a set, as some motor units fatigue and drop out, other motor units must be recruited for continued activity. The problem with this rational is that, by this rational, one could simply be able to exercise to failure with very light resistances and produce large gains in hypertrophy and strength.

Workout IntensityAs discussed earlier, this is not true. It is well known that heavy to moderate loads must be placed on muscles to achieve maximum hypertrophy. (5) Training to the point of failure has been shown in many studies to produce gains that are superior compared to when sets are terminated early. Although training to failure has been shown to be more effective, stopping sets just short of failure can also produce large amounts of growth.

This is because overload is the primary determinant for muscle growth, not failure. Continually lifting heavier resistances for all different rep ranges will overload muscles and force adaptations. This is easier said than done as anyone that has lifted weights for many years knows. Increases in strength are not always steadily moving up at a constant pace rather increases seem to ebb and flow. This is one of the reason why taking sets to failure is effective.

At some point in training, optimal gains are produced by taking sets to the point of momentary muscular failure. (6) Failure also may be the best way to increase the intensity of a workout. Once a training session begins, testosterone and growth hormone (GH) levels will increase within the first few minutes.

How high levels of both hormones go is directly related to the intensity of training. Intensity of exercise is the primary determinant for how much GH your body will secrete, while duration and volume have little to do with GH secretion (7). For this reason, training to failure can be a great way to increase the intensity your training and to take advantage of the increased anabolic hormone release.

One disadvantage of training to failure is that it is very taxing on the central nervous system. The nervous system is responsible for activating motor units during exercise. Although muscle tissue may be able to recover from taking many sets to failure, the nervous system will not. Some programs that call for all working sets to be taken to failure will definitely lead to overtraining.

Workouts must contain both sets to failure and sets close to failure along with periods of time where no sets are taken to failure. Many of the benefits of failure training can be had by taking a set very close the point of failure. Stopping a set 1-2 reps just short of failure will allow for sufficient fiber stimulation while sparing a lot of stress on the nervous system.

One thing to note is that high intensity overtraining has a much different affect than high volume resistance overtraining. The main difference between the two causes of overtraining is the effect it has on the endocrine system. With high intensity overtraining, catecholamines, which are the fight or flight hormones, actually show an increased response to training. Also, while volume related overtraining will cause a decrease in testosterone levels, intensity related overtraining will leave testosterone levels unaffected. (8)

The ultimate goal of any training program is to push as hard as possible while not overtraining. Bodybuilders are always tip toeing on the brink of overtraining and it seems that if that line is crossed the effects will be less detrimental if more intensity and less volume is used.

Putting It All Together

These intensity boosting techniques are different from those such as drop sets and supersets. Although those are great intensity boosting techniques and should definitely be used from time to time, principles of load, volume, rest periods, and failure must be adjusted in your weight training to ensure constant and steady growth for years.

These aspects of training are not independent of each other, and if one is adjusted all other must be adjusted accordingly. There is a reason nobody sprints a marathon. Appropriate levels of intensity will vary greatly from person to person depending on genetics, diet, and whether or not steroids are involved. Those who have made the choice to be natural bodybuilders have chosen a difficult road.

Natural bodybuilders must be more conscious of every single one of these points since drugs will not make up for the flaws within their training.  Be sure to take a hard look at the intensity level of your own training. In my experience, most lifters convince themselves that they are training more intensely than they actually are.

Many people have no problem going from set to set with very little rest periods. Many people have no problem lifting heavy weights or doing a lot of sets. You’ll find though, that very few people have the determination to strive to be great in every aspect of the word intensity. Doing so takes a level of planning and pain that most are not willing to go through.

My young training client returned from the restroom looking pale as a ghost. Sweat was still dripping off of him. I expected him to say that he was going to head on home. Instead he looked at me with a smile and said, “Man, what a great workout. I need to do this every week. So what’s next?” I knew then that this kid was going to do just fine at his show.


  1. National Academy of Sports Medicine, Optimum Performance Training for the Health and Fitness Professional: Course Manuel, 2008, 332p.
  2. Baechle, T. R., Earle, R. W., Essentials of Strength Training and Conditioning, 2008, 58p.
  3. Garret, W. E., Kirkendall, D. T., Exercise and Sport Science, 2000, 152p.
  4. Kreider, R. B., Fry, A. C., O’Toole, M. L., Overtraining in Sport, 1998, 153p.
  5. Frohlich, M., Pruess, P., Current Results of Strength Training Research: An Empirical and Theoretical Approach, 2005, 80p.
  6. Fleck, S., Kraemer, W., Designing Resistance Training Programs, 1997, 20p.
  7. McArdle, W. D., Katch, F. I., Katch, V. L., Essentials of Exercise Physiology, 2006, 410-411p.
  8. Chandler, T. J., Brown, L. E., Conditioning For Strength and Human Performance, 2007, 119p.
Posted on: Sun, 01/13/2013 - 19:21

Great Article Cliff!

I always reach failure between 4-7 (2 weeks) or 8-11 (4 weeks) reps depending on the week. I also decrease my resting period from 1:45 to 1:00 over a six week period while increasing the sets progressively. My question is, when training to failure do you always decrease the weight between sets? Obviously you can't get stronger from set to set so you either have to decrease the weight or lower the reps. I see a lot of other guys raising the weight each set and it just doesn't make sense to me. Thanks.

Posted on: Thu, 09/01/2011 - 01:31

hey im looking for a intermediate, fast paced full body workout. Any suggestions?

Cliff Wilson
Posted on: Thu, 09/01/2011 - 12:44

Hey Joel,

It is a little hard to give a suggestion without knowing a little more about you. I would take a little time and look through some of the programs available on the site and in the forums though.

I would like to make a suggestion though. I know you are just looking for an intermediate program but I would suggest at least splitting your workouts into upper and lower body sessions. This will give you far better results than doing your whole body in one session. I don't know how many days per week you lift but this is also a good split.

Day 1- Upper body
Day 2- Lower body
Day 3- OFF
Day 4- Back Delts
Day 5- Chest Arms
Day 6- Legs, Abs
Day 7- OFF


Hope that helps a little.

Posted on: Mon, 08/29/2011 - 19:40

I am one of those guys that actually uses a stop watch for my rest periods. I have my headphones on and nothing to distract me during my workout. My body type is "hard gainer", I can drop my body fat % and weight with little effort, but putting it on is the challenge. I eat clean and about 3,000 calories to maintain my weight. I have read that as a hard gainer I should keep my rest periods longer (2 minutes between sets and 3 minutes between exercises) in order to lift heavier. Am I missing out on some benefits of the shorter rest periods?

Cliff Wilson
Posted on: Tue, 08/30/2011 - 10:23

Oh Boy! I feel your pain. I have had to fight twice as hard as others to put on every ounce of muscle. I do think that you are missing out by not using shorter rest periods from time to time. In fact as a hard gainer you need to use more of the tools in the tool bag just to get your body to grow. Someone that grows easily can do the same thing day in and day out and make great gains. We have to keep changing things so our body doesn't adapt. I would only use short rest periods on workout that you are using 12 reps or higher. Just try doing a whole workout in the 12-20 range for every set and only take 1-1.5 minutes in between each set. Add in just a little more volume and I bet you will have one of the best workouts you've had in a while. Although your weights will be a little lower for that one workout, you will get a great growth hormone increase which will go a long way toward helping you grow.

So give it a shot. You'll be happy you did.


Posted on: Fri, 09/02/2011 - 05:29

I tried the shorter rest period of 1 minute between sets in my leg workout on Wednesday. I have to say that it worked great. Really stayed focused and did higher reps and did not drop my weights much below the weights I lift with the 2 minute rest periods. Can hardly walk today, which is great. How often would you suggest I use this technique with my body type? Thanks for the info.

Cliff Wilson
Posted on: Fri, 09/02/2011 - 21:14

I am glad you liked it. It usually kicks things up a notch. I do recommend doing longer rest periods a little more often than shorter rest periods but I use this technique whenever I feel that my weights are beginning to plateau a bit. But if I had to put a time table I think that doing this for at least a couple weeks straight every few months would be a good bet.

This will be enough change to stimulate change. Plus this way when you go back to longer rest periods you should notice a strength increase. This is because your body will become accustomed to replenishing energy stores at a more rapid rate. This will transfer into greater strength when going back to longer rest periods. So keep hitting it hard and you should make some nice progress.

Posted on: Mon, 08/29/2011 - 12:06

Hi Cliff!
Great article. I´ve been training for years now, sometimes i get the feeling that i´ve been overtraining for a long time, but are uncertain about some of the symptoms and how my body reacts.
Since i started i´ve almost always used high volume training, but with many different programs. Right now i´m doing the "HIML-4 Maximum Muscle Building Workout System" (in my 4th week), which i feel like is a good mix of what you mentioned in this article and in part one.
My question to you is, would you recommend that i try to do the same as you told Stephen above, about talking so light weeks? If so, how would i start up again? Do you think it would be a good idea for me to run a few months with a HIT program for a change (only tried a couple of week with HIT before), to prevent the overtraining?


Cliff Wilson
Posted on: Tue, 08/30/2011 - 10:18

Thanks for reading! I really do recommend using a deload week in any training program. Even doing this 2 times per year will yield benefits. I don't really recommend HIT. This will not yield as much results as a higher volume program. Some of the best gains I have made in my career have come on programs that people said I would overtrain on. The important thing is that periods of high volume are cycled and not continued for long periods of time with no backing off. Sometimes I will go as high as 16 sets per body part 2x per week. Then after 4-6 weeks I will back off to 8 sets per body part 1x per week. So the volume should be cycled to prevent over training.

I would still stay away from the traditional HIT style training. This just won't give you the gains you are looking for. The only time I recommend HIT to someone is if they just want to maintain a level of fitness and are really busy.

Let me know if you have any other questions.


Posted on: Wed, 08/31/2011 - 13:52

Thank you for the quick response and for doing this!
I´ll most def try the deload week and integrate it in my routine, maybe 3-4 times a year, as well as getting better to take a week off every 12th week.
The HIT training never really sounded like a hit in my book to, but you know people talk and you read all sorts of good things about it.
The volume training talks more to my heart and body to.
I use to work all body parts twice per week, but the last couple of years i´ve cut down to once per week, structured like this: Shoulder/tri/abs, Back/leg and chest/bi/abs, so the small muscle groups are hit once primary and once secondary, and feel like i´m really pushing me self every time.
What you´re saying is, that it´s a good idea to switch the volume from time to time, high vol. for 4-6 weeks and then cut down for awhile?
May i ask, what does your workout look like, if you where to do it like that? Do you use the same exercises ever time and what about rep range?
I´ve tried so many different routines the last couple of years, well especially since i discovered this site- a gift and a curse, when you your tempted all the time, to try out new programs. Know i´m just a little frustrated. Don´t wanna sound like a rookie, i´ve trained for many years, red and learn a lot lately (maybe thats my whole problem), and at the same time i´ve become more confused as well!! Especially the overtraining have been on my mind lately, so i really appreciate you taking the time.

Defiantly gonna experiment more with the rest periods again.

Cliff Wilson
Posted on: Thu, 09/01/2011 - 12:39

Sounds like you are a little unsure as to which direction you want to take your training right now. I would tell you what my training looks like but I can tell you that it is always changing. I do lay out a plan and a goal for whatever program I am on though. I do tend to lift with a combo of high and low reps most of the time, but there are times where I will do more of a powerlifting style program with mostly just low reps.

If you want to see a little of how I train and eat you can check out my forum journal on this site. I have been a little behind on posting but I am going to be making some new posts soon here. I will make sure to include my workouts as well. My name is in the title of the thread. Let me know if you have trouble finding it.


Posted on: Sat, 08/27/2011 - 21:14

Thanks Cliff, I also have another question if you don't mind. I see all of these guys who are extremely lean, meaning low body fat % and I have tried to get low in body fat and I have gotten close but I usually have to stop because I feel like such crap. Do these guys in fitness magazines and photoshoots get ripped just for the event or can they maintain that look all year around? When I was dieting I started in february and slowly dropped calories until july and I ended up at 2500 calories and felt like such crap, I had low testosterone, low sex drive, low energy, not much of a desire to lift and be able to be intense in the gym.

Cliff Wilson
Posted on: Tue, 08/30/2011 - 10:12

No problem Stephen. The guys in the fitness magazines usually do diet down for only short periods of time. Most guys do not look like that year round. There is a way to make yourself feel better while being lean though.

Many people that are dieting to get lean have a bad tendency. As soon as they hit their goal body fat level, they go immediately to a bulking diet. The problem is that this will put a lot of fat on them really fast. Once you get as lean as you would like just start adding calories back very slowly. Adding only about 75-100 calories per week will allow you to start feeling better and adding muscle while only adding small amounts of fat. Give this a try and you will see that you will feel better and better.

One other thought is that your macros may be off a little on your diet. I can't say for sure since I don't know what they are, but this can also make you feel like crap on a diet.


Posted on: Fri, 08/26/2011 - 00:01

Thanks Cliff, appreciate it.

Posted on: Wed, 08/24/2011 - 00:42

If it is in danger of dying it will put calories towards fat for survival right? I've done bulk cycles 3 times since I started lifting and honestly i'm kind of burnt out of going from 180 to 225, I feel like crap towards the end of the bulk and food becomes undesirable, so right now I'm looking to gain a little weight but very slowly, so i've been slowly increasing calories over the months. I will give that failure method a try, i can see why my strength hasnt increased much because my muscles probably get burnt out really quick by going to failure every set. The other night I barely took any sets to failure but instead just increased the weight and stopped a few reps shy of failure and I was able to keep a good amount of strength throughout the entire workout.

Cliff Wilson
Posted on: Thu, 08/25/2011 - 12:14

You are absolutely right about your body wanting to store fat in times of danger. You are also correct about gaining more slowly. This will help you retain more size in the long run. I am glad to hear you tried the close to but not quite to failure method. It works great, you will see that you will gain a lot of strength and size.

As for gaining slowly, I wrote an article about this too. If you search my article list you will find it. Good luck in your training.

Posted on: Mon, 08/22/2011 - 20:06

Hey Cliff, I've been training for around 2-3 years now and have put on a lot of size but have developed this habit of training to failure almost every set. I've tried stopping a few reps before I think i'm going to give out but it feels like i'm not doing anything. Even though i've gained a good amount of muscle doing this I feel like i've been going through the overtraining symptoms. At times I have a loss of energy, no desire to lift, depressed, moody, etc. I might also be eating too few calories, since i weight lift 4 days a week and play rugby twice a week I estimated that workload on the M&S BMR calculator and it says I need 3400 to maintain but im only getting 3000. 3400 calories has always been an amount that I bulk on but since im more active i really need to increase calories which would probably make me feel a little better. What do you think I should do about the failure issue? I find myself doing the same weights to failure because any more weight to failure ends up getting me shy to my desired rep range.

Cliff Wilson
Posted on: Tue, 08/23/2011 - 11:34

Hey Stephen,

I actually see this a lot. You are probably over training and have been for quite some time. I know you are not going to like this but I would recommend actually doing a deload week. This is a week where you do the same workouts for the same reps but cut the weigh by 50% from your usual. It is a really easy week but it will allow your body to get a week to relax. Then once you get back to regular training I would recommend doing a program where you take zero sets to failure for at least 2 weeks. Then after 2 weeks I would start taking the last set of every exercise to failure for about 4 weeks. After 4 weeks I would take the last 2 sets of every exercise to failure for another 3 weeks. About that time you should be feeling a little over trained. At that point you can back off the failure a bit or take another deload week. If you do this you will see some of the best gains of your lifting career. Remember your body cares about survival and survival only. If it constantly feels like it is in danger of dying it will not want to expend any calories on muscle.

As for you calories this would depend on if you are trying to gain muscle or are you trying to lose fat. I would need more info to give specifics.

Hope that help.