Although the amount of resistance you use and how many repetitions of each exercise you do and how many total sets you perform in a workout are important – there is much more to an effective resistance training program.
It’s not just about what you are lifting – how you are lifting it is equally important. Here are some of the key movement variables to consider:
What is your movement speed and is it constant or does it change and what are the effects of changes in movement speed or acceleration and deceleration during an exercise? As a general rule of thumb slower, controlled movements are safer and generate more time under tension for a muscle group. However the deliberate use of higher velocity movement or explosive movements can be very beneficial if done correctly using good form.
Body Position including placement of feet, position of the torso and hands during an exercise? Small changes in the position of your hands, feet and body can dramatically change what muscles are used. For example a squat done with feet and hips externally rotated will result in very different loading than a squat with feet and hips straight or only slightly rotated out.
Where is the load and line of resistance relation to your body? When using free weights of any kind (dumbbell, kettlebell, sandbag, etc.) gravity will pull down directly to the ground in a straight line from the load, and depending on the position of your body will determine which muscle/s are being challenged. If using a machine of any type the line of resistance is not always straight up and down because many machines use pulleys which redirect the force of gravity on a weight stack in differing directions.
What is the position of the resistance/load that you are using? For example doing a squat with a bar on your back is very different than doing a front squat with a bar in front of your shoulders and completely changes the emphasis of which muscles are producing the movement and the stabilization requirements of the other muscles such as torso muscles. Holding resistance on one side or the other such as single arm overhead press creates very different loading than using two arms at one time. Even doing the same exercise with dumbbells versus barbells substantially changes the loading and challenge.
What plane/s of motion are you moving through during each exercise and how does this relate to the activity or sport you are training for? The bulk of exercises most people think of are done solely in the sagittal plane meaning the movement is forward/backward or up or down. However the body also moves side to side and rotates not to mention movements that involve all three planes of motion. For example a squat with an overhead press can be done solely in the sagittal plane – you squat down holding the weight at shoulder height and then at the top press it overhead. If you take the same movement but rotate the body to one side as you pivot one leg to facilitate the turn you introduce rotational movement which really changes the exercise substantially.
How stable or unstable is the resistance/load you are using?
Using a fixed unmoving object such as a dumbbell, kettlebell or weight ball as resistance is very different than doing the same exercise with a less stable form of handheld resistance such as a sandbag. Unstable loads dramatically increase the challenge of an exercise requiring substantially lower loads for the same metabolic response.
How stable or unstable is your base of support during an exercise?
Try any exercise on the beach in sand versus a stable surface of any kind and you will immediately get the point here!
Change any one of these variables and you have a whole new exercise not to mention changing more than one at once and/or also changing the amount of load you are using. In general do NOT change everything at once but you can easily create variation in your program by adjusting more than just your sets, reps, and amount of resistance used!