Newton’s 2nd Law: Why You Need To Max Out

Remember high school physics class? Besides building an amazing rocket launcher that could fire an egg down the block (my team was awesome), the knowledge of Newton’s Laws proved an invaluable staple to strength and conditioning and the success of our services. Force, friction, inertia, momentum, leverage, and good ole’ gravity play a crucial role in performance gains and overall fitness.

In case physical phenomena are a bit fuzzy to recollect, let me review Newton’s 3 Laws:

1) An object at rest or in motion will stay in said state unless acted upon by another force.

2) The vector sum of forces on an object is equal to it’s mass multiplied by it’s acceleration.

3) Every force action has an equal and opposite reaction force.

Think of a back squat. Gravity of the barbell and weight is acting directly downwards on your body and will continue to do so unless you produce force to counter it. Your muscle contraction produces force acting against a solid floor which in turn act upwards against you and the barbell. If said force is greater than the force of gravity and barbell, the barbell will change direction and proceed upwards. Simplified physics with extreme application. What coaches want to know is how much force can their athletes produce and is that force transferable to their sport. As strength and conditioning specialists, we need to be able to break down the science and create better athletes.

A Bullet and A Dump Truck

Let’s break this down. Force=Mass x Acceleration (F=ma). Increasing one of the two variables (mass or acceleration) will then increase the vector sum of force. Turning to strength training, we associate mass with maximal strength (how much weight can we move) and acceleration with dynamic strength (how fast can we move said weight).

Matt Wenning broke it down perfectly with his example of a bullet and a dump truck. One weighs 32 tons, the other only a couple grams. A dump truck in motion can certainly make an impact, even when travelling slow. Although acceleration is minimal, the mass of the object is incredibly high resulting in a greater force production. A bullet is barely heavy enough to make the needle on the scale move but when fired can travel almost 2500 feet per second. The acceleration is superior to it’s mass which in turn reflects it’s high force production. Mass and acceleration determine force production, no matter which side of the equation is favored.

Maximal Strength & Dynamic Strength

Taking the 2nd Law into consideration for strength training means examining how much mass can be moved and how fast one can move said mass. We know the body adapts to training and that different stimuli result in different adaptations, especially with speed and strength. We assume that if you want to get faster, you simply train at higher velocities. Although this has some truth, remember the 2nd Law. Increasing one of the variables can then increase the result of the remaining variables. Put simply, training at maximal strength capacity can improve it’s dynamic counterpart.

Let’s say you have 2 athletes, Tom and Jerry. Tom can squat 500lbs for 1RM and Jerry can squat 200lbs 1RM. You ask Tom and Jerry to find a weight they can lift for 10 reps as fast as possible while challenging themselves. Tom does 300lbs and Jerry does 85lbs. Both are moving at the same rocket speed, but Tom is moving more mass. His dynamic strength seems greater because his maximal strength is also greater.

Another example would be looking at a deadlift and a power clean. The deadlift is more maximal in nature whereas the O-Lift is all about speed of the bar. If Tom can deadlift 800lbs, power cleaning 300lbs shouldn’t be an issue. If Jerry can only deadlift 500lbs, 300lbs may prove to be a struggle. On the flip side, if Jerry can power clean 150lbs extremely fast, it’s likely Jerry can deadlift 400lbs. Being able to accelerate more mass faster leads us to look at the Force-Velocity Curve and assume that more mass could be moved at a slower speed. Check out the visual, it’ll help clarify some things. Put simply, moving towards more force means slower velocity. Moving towards increased velocity means a decrease in force.

How Do I Adapt?

The training process varies but the goal is to continually train at higher intensities more frequently to increase maximal strength. Although practical on paper, the neurological recovery from max effort training is quite substantial, sometimes upwards of 72 hours. It’s easy to see why athletes believe max effort strength training isn’t as demanding on the body with such low volumes. The truth is that although volume and perceived exhaustion levels after a session may seem low, your central nervous system is begging for a break.

Strength is the ability for one to exert/resist force. To produce greater force requires the body to recruit more motor units to innervate and contract musculature. This innervation process is quite demanding and requires sufficient time to recouperate. If you were to include additional practices, games and daily activities, that’s a heavy workload for one’s body, hence why appropriate planning and recovery is encouraged.

For the average exerciser, picking one big lift to go heavy on is sufficient if done every week or two. Ensure form first and then start stacking on the plates to really crank up your session. If you’re an athlete, consult your strength coach. Depending on games, practices, intensity of said practices mean your heavy days may be more sporadic or frequent.

For the lifting enthusiast, consider variety to boost your gains. You’ll never get rid of the big three, but you can certainly change up the variation. Try maxing out your front squat or your overhead press. Try using a trap bar for deadlifts or switch stance to sumo. The little changes every few weeks enable your central nervous system to recruit differently and speed up recovery. Plus, the variation adds improvement to other areas which in turn help support your main lifts. All good things.

The Take Home

I’m not trying to give the impression that a powerlifter who can squat 800lbs is going to run the 100m dash in under 9 seconds. The point I’m trying to get across is that maximal strength assists dynamic strength. If you want to improve power, increase your maximal strength. This will lead to greater force production and the ability to move the same mass (tried previously) faster than before (providing appropriate training consistency and time for adaptation).

The key is in the education. Too many coaches, athletes and fitness enthusiasts assume doing the same training at higher velocities will lead to better results but unfortunately this isn’t always the case. Being able to move more mass (in whatever direction) means being able to move less mass faster. Athletes of all backgrounds need to be appropriately maxing out to improve performance irregardless of their respective sport. The ability to generate more force and strengthen tendons, bones and joints mean a healthier and more powerful specimen. Consider this next time you’re sitting under the apple tree.

Coach Matrixx

Matrixx Ferreira

Matrixx specializes in adolescent athletic development. He coaches some of the top athlete prospects coming out of high school in the Niagara region. He also works with dedicated members of the community who are passionate about improving personal fitness. Matrixx is also the author of The Iron Guide to Building Muscle.

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2019-03-05T10:35:50-07:00