What's the most important question you ask your fellow gym rats when you show up at the gym? How much do you bench? What muscles should I focus on today?
While these topics are definitely popular, there is one question that often gets overlooked: How long should I rest?
That's right. What if I told you that you may be missing out on strength gains because you're working too hard in the gym? Yes, you heard me correctly. The amount of time you rest between sets has a major impact on the type of exercise you can undertake, and it should not be taken lightly.
First of all, why do we need to rest between sets? Why can't we just train non-stop? The answer often has to do with chemical processes inside the body that cause fatigue and act as a safety measure to prevent muscles from being overworked. One general rule of thumb is that the heavier the weight you're using, the longer your rest should generally be. For example, the recommended rest breaks when trying to improve your one-rep max Deadlift are quite a bit different than when you're attempting to pump up your biceps.
Your rest breaks need to reflect your training goals, whether they involve endurance, strength, power or hypertrophy.
Endurance Rest Intervals
When thinking about resistance training for endurance performance, we commonly think "low weight, high reps." Scientifically, this equates to loads of less than ~67% of your one rep max, and banging out more than 12 reps per set.
How much should you be resting when muscular endurance is your primary focus? Typical rest breaks are short, lasting between 30-60 seconds. The biggest guide is that the break is long enough for you to hit your repetition goal, but ideally no longer. Modify or adjust the training load to maintain the appropriate number of repetitions.
Why such a short rest period? This type of training relies heavily on oxidative metabolism and increases your body's mitochondrial density (remember back to your 8th grade Biology days, the mitochondria is the "powerhouse" of the cell). More mitochondria, more aerobic metabolism, greater endurance. Boom. Science.
Hypertrophy Rest Intervals
Well, what if you want to get bigger? Not only must you make sure you are lifting heavier weights (~67-85% of your one rep max) than you would when the focus is endurance, but the volume has to be correct (between 6-12 repetitions) and the rest break also needs to be slightly altered.
Lots of research has compared human growth hormone levels accumulated with short rest intervals (60 seconds) vs. long rest intervals (180 seconds). What have they found?
Higher levels of growth hormone were found in the one-minute rest groups than the three-minute groups, leading to a higher hypertrophic effect.
So what does this mean? Instead of spending five minutes swiping through your social media, get back underneath the bar no more than a minute after your last set to maximize your body's internal pharmaceutical cabinet.
Strength/Power Rest Intervals
Now if your goals are focused on improving strength or power output (loads typically >80% of one rep max with less than 6 repetitions), you have to make sure your mid-workout siestas are adequate.
What's enough? Most studies indicate greater than two minutes, with some breaks lasting upwards of five minutes.
Why so long? Not only do you have to allow for the recovery of high energy substrates used in anaerobic metabolism, but the technical nature of these lifts requires adequate central nervous system recovery.
If you're training for strength and power, 2-5 minutes between sets is usually ideal.
When it comes to resistance training, many people rarely utilize the right rest interval for their goal. They say they want to build muscle, but they're scrolling through Instagram for six minutes between sets instead of getting back to action 30-60 seconds later. Or they say they want to get stronger, but they're utilizing such short rest periods that they become incapable of lifting the heavy loads needed to make significant strength gains.
Of course, different guidelines apply to certain modes of exercise, such as circuit or complex training.
Additionally, the technical nature of the lift, your training status, variability of performance, fatigue levels, etc., can play a role in how much rest you may need to take during any given workout.
However, rest intervals should not be overlooked. It's best to program them ahead of time so you stay on track during your workout, and then adjust on the fly if needed.
Photo Credit: nd3000/iStock
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