How heavy should you lift for size vs strength vs power?
Reading time: 3-5 minutes
Take-aways
For 1RM strength, your training should be very heavy.
Try to structure your training in a manner that allows you to train the key lifts heavy. Train the main lifts first in a session. Allow for plenty of rest before a heavy session. Don’t use modalities that reduce the load excessively (e.g. squatting on a bosu ball, bamboo bar bench).
For jump and power performance, the load you use should be more moderate.
For jumps, try a load around one third of your 1RM.
For power outcomes, try a load around 50-60% of your 1RM.
For agility outcomes, the load you use doesn’t really matter.
For sprint performance, heavy loads appear more beneficial.
Try using a load around 80-100%1RM.
For muscle growth, a variety of intensities can work (~30-85%1RM).
Avoid intensities below 30%1RM or above 85%1RM.
Let me cut to the chase.
A recent pre-print by Swinton and colleagues combined findings from 295 studies (!) to determine the relationship between intensity (%1RM) and strength, sprint, agility, jump and power type outcomes. Agility type outcomes included ladder drills, footwork drills, change of direction work and more.
If the most weight you can squat for one rep is 500lbs, for example, 500lbs would be your 1RM. Intensity - or load - can be viewed as a % of your 1RM (500lbs). 80%1RM, for example, would be 500 x 0.8 = 400lbs.
Here’s what they found.
Lifting weights has the greatest beneficial effect on strength, followed by jumping, power and agility performance. Sprinting came in last.
For strength, there was a positive relationship between %1RM and improvements in strength. Lifting heavier was better, all the way up to 100%1RM. So, if you’re looking to get stronger, you should probably be lifting very heavy for at least some of your training - and the heavier, the better.
For sprint improvements, lifting heavier also seemed better, though benefits really start showing past about 80% 1RM.
For agility, the intensity doesn’t seem to play too much of a role.
For improvements in jumping performance, lower intensities around 30% 1RM actually seemed to result in the greatest improvements. This is in-line with much of the old-school strength & conditioning thinking - since power output is highest around 1/3 of your 1RM, this is where training for jumping performance should take place.
Training for overall power appears most productive when intensities of around 50-60%1RM are used.
Before you ask, this meta-analysis didn’t look at muscle growth. However, we have relatively compelling data that hypertrophy would be similar enough across about 30-85%1RM. That said, growth is probably worse below 30% 1RM due to insufficient load. Above 85%1RM, it’s also worse due to insufficient volume load accumulated - you just can’t do enough reps with a load that heavy for it to be efficient.
Why?
Performance improvements usually follow the principle of specificity. Your training should resemble the outcome you’re trying to improve in. For maximal strength, that means lifting very heavy. For power outcomes, that means using a load that isn’t too different from what maximises power output (around a third of your 1RM). Agility outcomes didn’t really have a relationship with intensity, which makes sense since they are closer to being a test of coordination than a test of force production.
If you’d like to chat about this study, feel free to comment below.
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