Constant Tension Training

There’s a good chance you’ve noticed a shift in your gym lately. The sole power rack in the corner of your free-weight area, once dust-covered and neglected, is in high demand. The few squat racks are being used for actual ass-to-grass squats rather than curls and shrugs. And the cushy seated machines with selectorized plate stacks are slowly being pushed to the periphery. It seems basic barbell training and compound lifts are all the rage these days — and for good reason, since no other training methods can pack on mass with the same efficiency as the tried-and-true staples like the bench, squat and deadlift. Machine-based movements, on the other hand, have come under fire because they tend to push trainers into unnatural movement patterns and strength imbalances. 

The big lifts are all well and good for anyone whose goals are strength and size, but the trend toward compound movements negates the essential role that machines play in hypertrophy. What the classic bodybuilders knew — and what today’s upstarts need to learn — is that pushing major weight while activating multiple muscle groups is only part of the equation, and machines still play an essential role in bodybuilding by allowing a lifter to apply consistent tension to a working muscle through a complete range of motion. At the bottom of a barbell curl, there’s not much tension on the muscle.Enter contrast training, which takes its inspiration from the time under tension produced by machines and tweaks basic compound movements to make them just as ideal for hypertrophy. In other words, you get the best of both worlds without sacrificing your new found love for squats.

Partial Approach

When most lifters talk about performing partials, they’re referring to the last portion of a rep. Typical examples include the quarter squat and the rack deadlift or “rack pull,” where you perform only the top third of the movement to lift heavier without working through an exercise’s common sticking points. These types of partial-rep exercises are great if you’re a powerlifter looking to build strength and “lockout” ability in the major lifts, and they’re also useful if you need the ego boost of moving weight you could never handle through the full range. But if your goal is to maximize hypertrophy, you’ll need to focus on a different partial range.
To make significant gains in size, you need to emphasize the mid-range portion of every rep, as that’s where you’ll be recruiting the highest number of motor units while you’re moving weight. Simply put, more motor-unit recruitment means more productive workouts, which means increased gains in size and strength.

Work the Middle

There’s a fundamental concept in the science of muscle physiology called the “length tension relationship,” which refers to how much force a muscle can generate relative to its length. As numerous studies have shown, muscles exhibit the highest force output when working from somewhere between fully elongated (stretched) and fully shortened (contracted). Simply put, for every exercise you use to get bigger, stronger or faster, your muscles exert maximum force in the middle range of a rep. Additionally, the more force you generate within this “mid range,” the more motor units you recruit, which means you’ll be bringing more muscle into the game.

The practical application of all this increased muscle activity is the “mid-range partial,” which takes the increased strength potential of the standard partial rep and moves it to the middle, shifting the partial’s purpose to an emphasis on hypertrophy. Performing a mid-range partial rep is as simple as it sounds. Throughout your entire set you’ll stay in the middle of the range. While the mid-range specifics will vary for each exercise, the basic principle remains constant: You’ll never fully lock out the weight, nor will you ever go all the way to the bottom of a lift. Essentially, you’re eliminating both ends of the range of motion and concentrating just on the middle.
In addition to activating more motor units, mid-range partials offer another major benefit for big-time muscle building: They force you to keep constant tension on your working muscles, as the lack of locking out or full extension prevents them from resting at any point during your entire set. This constant-tension method ensures that active muscles receive more time under tension, which, like increased motor-unit recruitment, is a battle-tested and scientifically proven way to gain muscle mass.

Keep in mind, however, that the mid-range partials used in constant-tension training aren’t something you should be doing for every set. If you never force your muscles to work through a full range of motion, you can expect losses in mobility, which is why the accompanying workout calls for a few mid-range partial sets and a few full-range sets for many of the lifts.

Rage with the Machine

The beauty of the constant tension method is that it can be applied to virtually any exercise. That said, you’ll find it’s most useful when applied to free-weight movements. Because of the nature of machine-based exercises, there’s no need to augment them to achieve constant tension. To understand free-weight vs. machine biomechanics, let’s use a biceps curl for example. During any style of biceps curl, the point at which your biceps are maximally loaded is the point in the range of motion in which your forearm is at a 90-degree angle with the load vector. If you’re using free weights, gravity is your load vector. So the point of maximal loading would be when your elbow reaches 90 degrees of flexion or when your forearm is parallel to the floor.

If you’re doing biceps curls using a cable column, the cable itself is the load vector, and the point of maximal loading is when your forearm forms a 90-degree angle with the cable (which is coming from an angle). The farther your elbow flexes (or extends) beyond that 90-degree angle, the less stress you’ll place on your biceps. In other words, during a free-weight biceps curl, as the dumbbell approaches either your shoulder in the top of the motion or your thighs in the bottom, your biceps are receiving significantly less stimulation.

Machines for the most part, unlike free weights and cables, are neither gravity dependant nor load-vector dependant. Because of their cam-based design, they provide constant tension to the working muscle throughout the entire range of motion. So when you perform biceps curls on a machine, you’re working just as hard at the bottom position (elbows extended) as during the mid-range and at the top position (elbows fully flexed).

The take-home message here is simple: If used properly, machines can be a powerful weapon in your muscle-building arsenal. And despite the importance of compound free-weight movements for increasing size and strength, anyone whose main goal is muscle hypertrophy should absolutely include machines in his program.

Timing Is Everything

Another component of the constant tension method is timing. With this protocol, you’ll find that performing each set for a given amount of time is more effective than counting reps. Each of the mid-range partial sets in the accompanying workout calls for lifting the load for a prescribed number of seconds, for a focus on time under tension rather than total reps performed. Science shows that this method, when done correctly, is actually as scientifically sound as counting reps.

When performing mid-range partials as timed sets, don’t worry about your total number of reps or rep speed — these factors won’t matter. All that counts with constant-tension training is that each rep within a set remains within the middle range of the movement. Make this your priority and maintain strict form on each exercise, and you can rest assured that your working muscles will receive some serious stress regardless of how many actual reps you perform. Keep in mind, however, that you’ll be performing prescribed rep counts (not seconds) for machine-based moves in this workout, as machines already offer constant tension for reasons described above.

Constant Tension Workout

Use this program for the next six weeks to combine the time-under-tension benefits of machine-based moves with the anabolic boost of compound barbell lifts. For all moves shown in bold, check out the corresponding exercise description before performing them.

Day 1: Chest & Tri's

EXERCISE	SETS	TIMING*/REPS
Bench Press (mid-range)	3	45 seconds
Bench press (full range)	2	6-8
Incline Dumbbell Press (mid-range)**	3	45 seconds
Incline Dumbbell Press (full range)	2	6-8
Cable Crossover	4	8-10
EZ-Bar Skullcrusher (mid range)	2	6-8
EZ-Bar Skullcrusher (full range)	4	10-12
Triceps Pressdown	4	10-12

*Without counting reps, perform the mid-range partial movement for the prescribed time. Rest one minute between sets.
**For the mid-range reps, lower the weights until your elbows reach a 90-degree angle, and never lock out your arms at the top.

Day 2: Legs

EXERCISE	SETS	TIMING*/REPS
Back Squat (mid range)**	3	45 seconds
Back Squat (full range)	2	6-8
Dumbbell Split Squat (mid range)	3	45 seconds
Dumbbell Split Squat (full range)	2	6-8
Bulgarian Split Squat (mid range)	3	45 seconds
Bulgarian Split Squat (full range)	2	6-8
Leg Extension	3	10-12
Lying Leg Curl	3	10-12
Standing Calf Raise	4	15

*Without counting reps, perform the mid-range partial movement for the prescribed time. Rest one minute between sets.
**For the mid-range reps, descend until your thighs are parallel to the floor, and stop a few inches short of lockout in the top position.

DAY 3: Back & Bi’s

EXERCISE	SETS	TIMING*/REPS
Wide-Grip Lat Pulldown (mid range)	3	45 seconds
Wide-Grip Lat Pulldown (full range)	2	6-8
Seated Cable Row (mid range)**	3	45 seconds
Seated Cable Row (full range)	2	6-8
Hammer Strength Row	4	8-10
Dumbbell Biceps Curl (mid range)	3	45 seconds
Dumbbell Biceps Curl (full range)	2	6-8
Machine Preacher Curl	4	10-12

*Without counting reps, perform the mid-range partial movement for the prescribed time. Rest one minute between sets.
**For the mid-range reps, pull the close-grip handle all the way into your midsection during the concentric portion, but stop a few inches short of locking out on the negative.

DAY 4: Shoulders, Traps & Abs

EXERCISE	SETS	TIMING*/REPS
Seated Overhead Barbell Press (mid range)	3	45 seconds
Seated Overhead Barbell Press (full range)	2	6-8
Dumbbell Lateral Raise (mid range)**	3	45 seconds
Dumbbell Lateral Raise (full range)	2	8-10
Front Dumbbell Raise (mid range)**	3	45 seconds
Front Dumbbell Raise (full range)	2	8-10
Dumbbell Shrug	4	12-15
Weighted Swiss Ball Crunch	5	12-15
Swiss Ball Pike	5	12-15

*Without counting reps, perform the mid-range partial movement for the prescribed time. Rest one minute between sets.
**For the mid-range reps, maintain at least 5 inches between the dumbbells and your thighs in the bottom position, but still go slightly above parallel in the top position. 

Nick Tumminello is the owner of Performance U: Speed, Strength & Conditioning in Baltimore, MD, where he works with bodybuilders and athletes from the NFL, NBA and UFC. Visit his website at nicktumminello.com