T Nation

Rest Intervals

Has anyone experienced improved strength and muscle gains by increasing their rest intervals between sets? The past couple of years I?ve followed very short rest intervals, i.e., between 45-90 seconds depending on the number of reps. Over the last six weeks I have been using 180 seconds for reps between 12-15, 150 seconds for reps between 8-11, and 120 seconds for reps between 5-7. I?ve seen my strength increase by about 10-20% and my bodyweight increase by four pounds. I?ve played with all the other parameters, but couldn?t provoke many changes.

It occurred to me that when I first started out lifting and experienced my best gains, I never worried about the RI. Obviously, increasing rest intervals can lead to marathon training sessions and a decrease in focus, but maybe some people need it.

Has anyone else had success by taking a little longer between sets and what could be the possible factors that lead to increased performance from longer rest intervals.

The longer you rest between sets the stronger you will get, no question. That’s one reason Powerlifters rest a long time between sets.

When you rest 1 minute you are about 85% recovered. When you do sets with 1 min rest, fatigue sets in so you are not able to do as much in later sets. If you wait longer say 5 min then you are 99.99% recovered. When you are fatigued you cannot do as much weight. Being able to produce maximum for every set may be the reason…

Rest Time_______% recovered
1 min___________85%
2 min___________97.75%
3 min___________99.6625%
4 min___________99.9494%
5 min___________99.9924%

I have had great gains in strength using longer rest periods. When I am doing deads, squats, cleans, etc. I rest about 3 minutes between sets. That is about the time when I feel ready to go again. I understand about the marathon sessions but if you are going heavy you will not be doing as many reps and will not need as many sets. Try doing a 5X5 workout, your strength will definitley improve.

[quote]gar18 wrote:
Has anyone experienced improved strength and muscle gains by increasing their rest intervals between sets? The past couple of years I?ve followed very short rest intervals, i.e., between 45-90 seconds depending on the number of reps.
[/quote]

I think you explained the reason for your recent success in your second sentence. If you’ve been using the same rest periods for several years, you were due for a change and it’s no surprise that your body responded as it did.

WARNING! Very simplified explanation of muscular hypertrophy to follow. In other words don’t jump down my throat for omitting some things. :slight_smile:

The dominant energy system used for short duration, high intensity exercise is the ATP-PC system. Once the cellular reserves of ATP-PC are depleted, your body will rely more on fast glycolysis for energy production. Fast glycolysis is the breakdown of stored carbohydrates without oxygen.

Once you’ve depleted ATP-PC stores by doing a set of heavy squats, or a 100 meter sprint, it ~ 3 minutes for those stores to be restored. If you attempt another set of squats, or a sprint before the 3 minute mark, you force your body to rely more on fast glycolysis for energy. Since FG is not capable of supplying ATP as rapidly as the ATP-PC cycle, your strength/speed will go down on subsequent sets.

So what does this mean? Muscular hypertrophy that results from short rest period training is not only the result of accruing more contractile protein, but also from more stored carbohydrate and the water, enzymes etc. needed to use it. Muscular hypertrophy that results through training with complete rest periods is more likely to be solely from more contractile protein.

So the best type of training really depends on your goals. If getting bigger is one of your main goals, don’t abandon short rest periods. Take a look at Chad Waterbury’s TBT workout. That program is a great example of how to periodize not only sets, reps, and exercises, but also rest periods since it switches from straight sets to supersets from week to week.

I find cycling rest periods to be very effective and sound. When I want to get stronger, I train very frequently(4-6x) and very briefly with long rest periods. After that I may take my new found strength for a test drive by doing a mass cycle with short rest periods, lighter weights and higher volume.