Rest periods between sets is an integral and often overlooked contributor to the success of any strength training program. Chances are, you are not optimizing this crucial variable. So what is the trick to get the most out of your rest? Well, it depends on your training goals and level of conditioning. Optimal rest periods between sets can vary from 30 seconds or less up to 5 minutes! We know that it takes 2.5 to 3 minutes for the phosphagen (Creatine Phosphate/ATP) stores to fully recover from a set of intense exercise(1). Contrary to what you might think, resting for this time period to allow complete phosphagen recovery is not optimal for all athletes. Let's take a look at some of the facts about rest intervals. I have grouped the information by training goals in order to make it more reader-friendly.
Absolute Strength Athletes
First, let's define who you are. You are training for explosive, low repetition activities of short duration. Muscle hypertrophy and endurance are not your primary concerns. Weightlifters, powerlifters, sprinters, football players, sprint cyclists and any other athletes in a sport emphasizing high intensity/short duration activities, this is you!
Your optimal rest period range between sets is 3 to 5 minutes. One reason for this longer rest is to allow full phosphagen recovery before you begin the next set. Full recovery allows you to produce the greatest muscular force possible for each set performed, and thus receive the greatest absolute strength gains from your training. Another good reason for this rest interval is that when combined with heavy training loads, it appears to produce greater testosterone levels in experienced strength athletes incorporating large muscle group exercises in their training (2). A higher testosterone level equates to greater gains in strength.
Hypertrophy and Endurance Athletes
Who are you? You are an athlete training for muscular size and/or to increase your ability to apply near maximal muscular force over a time period. Bodybuilders, fitness buffs, long-sprint runners/swimmers/cyclists, wrestlers, soccer players, and sports similar in intensity, this is you!
Your optimal rest period range is 30 to 60 seconds. Another way to look at this is to shoot for a work-rest ratio of 1:1. This means that you spend the same amount of time resting as it took you to complete the previous set. Athletes whose sport demands 1 to 3 minutes of all out effort with little or no rest may benefit from a work-rest ratio of 1:1 or slightly higher. This means that you spend the same or less time resting than you do performing each set of exercise (1). In either case, the principles behind the practice are the same. Using this rest interval between sets creates high lactate levels in the exercising muscles (3). This forces the body to improve its ability to buffer the accumulating lactate, thereby improving your ability to sustain moderate, near maximal or maximal contractions over a given time period. High volume, short rest period training has also been found to increase human growth hormone levels when compared to training with longer rest periods (2). In addition, muscular hypertrophy (growth in size) will be maximized using the 1:1 work-rest ratio in conjunction with high training volume and a weight load between your 8 and 12 repetition maximum. (1).
Special Considerations
Keep in mind that whatever you are training for, beginners need more rest between sets then the seasoned veterans. If you are just starting out, stay in the conservative end of your range. If you are experienced you will benefit more from a shorter rest period. In addition, athletes coming back from periods of detraining due to injury or otherwise should increase the amount of rest between sets until you are back in your normal physical condition.
The Unique Case of Circuit Training
Traditional circuit training incorporates a rest period of typically less than 30 seconds, or a work-rest interval a fair margin greater than 1:1. So where does this fit into an athlete's training? One has to understand that circuit training is designed to provide a happy medium between strength and aerobic training. Due to the short rest interval between sets, strength gains are less than optimal with circuit training (30 to 50% less) when compared to traditional strength training (1). However, modest gains in aerobic capacity can be achieved. So who benefits from circuit training? Athletes that require a balance of both strength and cardiovascular endurance for their sport, athletes and fitness buffs with limited time and anyone wishing to add variety to their training would all benefit from circuit training.
In conclusion
No matter what your sport or fitness passion may be, understanding the science of rest between sets will put you in the driver's seat on the road to your training goals. As you can see, not all athletes benefit from waiting the full three minutes for complete phosphagen recovery. Different periods of rest can produce very specific results. It is up to you as the athlete to decide which approach will be of greatest benefit to you.
. Mijn hasjolie is momenteel meer een hasjbol omdat ik dat wel fijn vind (en ik het in kneedbare vorm heb gekregen van een maatje). 
. Ik was toen super druk met scriptie maar ik moest savonds gewoon ff trainen. Had dit ook gezegd tegen mijn bedrijfsbegeleider en die vond het niet zo verstandig omdat er nog redelijk wat aan mijn rapportages moest gebeuren. Mijn simpele oplossing: later naar bed gaan. Uiteindelijk lag ik die avond om 06:00 pas op bed 
(sowieso lezen er ook mensen mee waarmee ik IRL train 
, maar vergeleken hoe ik een jaar geleden trainde is dit voor mij al echt weinig! Maar goed dat je me erop wijst want ik had het gevoel weinig oefeningen te hebben gedaan maar alsnog 8 voor de rug! Al vind ik bij rug dat er wel ietsjes meer mogen dan bij bijv borst 
(en extra spierweefsel aan te spreken)
