Let's talk about reps, baby! Wait, what's a rep? Reps is short for repetitions. Repetitions define the number of times to perform an exercise. For example, you might do 12 squats, then stop. That's 12 reps. Sometimes people get reps and sets confused. Sets refers to how many times you will repeat that exercise for a particular number of repetitions. For example, you do 12 squats and rest. Then you do another 12 squats, rest, and then another 12. You have now completed three sets of 12 reps. Let's dive more into the anatomy of a rep or repetition: specifically, the 3 phases of contraction to every rep, why they're each uniquely important, and how you can maximally use them for your goals to build strength, muscle and to be more defined.
ECCENTRIC is the "muscle lengthening" part of the rep. In a bicep curl, the eccentric phase is when you're lowering the weight allowing the bicep to lengthen and stretch. Although the muscle is lengthening, it's not resting. The eccentric contraction is actually the strongest contraction and there are some effective "overload" strategies you can utilize for emphasized eccentric training to make HUGE strides in your muscle building and strength building progress. For example, I like to do slow, controlled eccentrics, also called slow negatives. I do slow negative sets whereby I lower the weight for a count of 3-5 seconds. This is a good overload strategy if you need to shake up your training. Slow eccentric training creates more mechanical damage and this is good damage...it's one of the two most critical stimuli for hypertrophy and strength adaptations. Most people speed through the eccentric and/or cut the range short. If you really want to get the most out of your training and make major strength and muscle building progress, you need to go slow and controlled...slow and steady wins this race. No cheating the reps. The eccentric phase is abSWOLElutely critical! Own it!
ISOMETRIC is the "non-moving" part of the rep in which your muscles are generating force but not generating a change in muscle length. Think static holds. This could be for the brief moment in between the eccentric & concentric. I often will pause for 1-2 seconds in this portion of the rep...at the peak contraction. Try doing an isometric hold at the bottom of your squats for a killer burn or holding for 2 seconds at the peak contraction of each bicep curl for a killer pump!
CONCENTRIC is the "muscle shortening" part of the rep where the muscle produces forces and actively contracts. This is the showy part of the contraction: ask someone to flex and they'll probably show you a bicep flex. In a bicep curl, the concentric phase is when you're raising the weight. This is the portion of the rep most people cheat on by involving momentum. Use your muscles, not momentum. We aren't simply moving the weight from point A to point B...we are controlling the weight through a FULL active ROM (range of motion). A key in this phase is to activate your mind to muscle connection to deliver a hard, deliberate squeeze as you contract and then pause briefly at the peak contraction.
Putting it all together...let's look at the squat. Squatting down is the ECCENTRIC portion. Muscles are lengthening to control the descent. Then if you were to hold at the bottom of the Squat, you would be maintaining an ISOMETRIC contraction. Then on the way up, you will go through a CONCENTRIC contraction and the same muscles that lengthened on the way down will shorten on the way up.
Don't forget to breathe! Breathing is also an important aspect of making the most of your reps. Exhale during the concentric phase, and inhale on the eccentric phase.
Make every rep count!