There's no right or wrong set and rep scheme. There's only what works best for you and your specific needs and goals.
You can make progress with almost any program, provided you work hard. Still, some programs are better suited to specific goals than others.
What's the best set and rep scheme for size and strength? Is it 3 x 10? 5 x 5? 9 x 3?
With so many seemingly effective options, it's difficult to know which is best. Fortunately, we don't have to choose one scheme at the expense of the others, because all can work. It just depends on your goal.
With that in mind, here are some proven set and rep schemes for several different training goals. These set and rep schemes aren't the only valid options – they're simply my favorites and the ones I use regularly with clients.
Maximal Strength
Description: Maximal strength can be displayed by lifting as much weight as possible for 1-5 reps. Improving maximal strength is beneficial for a variety of trainees ranging from high-level athletes to recreational lifters. As Louie Simmons told me, "Maximal strength is the foundation of all other strength qualities."
Appropriate Training Percentages: 85-100% 1RM
Best Set & Rep Scheme: 3 x 3
Reasoning: 3 sets of 3 reps allows the lifter to handle near maximal loads without pushing to the point of a true one repetition maximum (1RM). In doing so, the lifter can achieve an adequate strength stimulus without worrying as much about technical breakdown.
Speed and Power
Description: Speed and power can be displayed by lifting a sub-maximal weight with the highest attainable speed. Improving speed and power will positively transfer to a variety of daily life activities as well as sports performance.
Appropriate Training Percentages: 40-80% 1RM
Best Set & Rep Scheme: 9 x 3
Reasoning: While speed and power can be developed with higher rep ranges, I prefer to use more sets (9) and fewer reps (3) as it facilitates proper technique on all repetitions and delays the onset of fatigue.
Hypertrophy
Description: Muscle hypertrophy can be mediated by two primary factors: mechanical tension and metabolic stress. While a variety of set and rep schemes have been shown to promote muscle hypertrophy, some methods are more convenient – and possibly more effective – than others.
Appropriate Training Percentages: 65-85% 1RM
Best Set & Rep Scheme: 4 x 8
Reasoning: A moderate range of 4 sets of 8 reps allows the lifter to handle loads that stress the muscle quickly while facilitating sufficient time under tension. Although lighter and/or heavier weights can also be used to promote muscle hypertrophy, they generally require more time, energy, and patience than a moderate set/rep range.
Endurance
Description: Muscle endurance can be displayed by repeatedly lifting a sub-maximal weight without accumulating fatigue. Training for muscle endurance holds numerous benefits including improved athletic performance, general health, and even recovery.
Appropriate Training Percentages: 20-70% 1RM
Best Set & Rep Scheme: 3 x 20
Reasoning: A set and rep scheme of 3 sets of 20 reps allows the lifter to work for extended periods of time, thereby improving muscular endurance. For the best results, rest between sets should be minimal (30-60 seconds).
Sample Program for Mass and Strength
Now that we've covered the essentials, you can use this knowledge to design a training program geared towards your specific goals.
As an example, here's a 4-day upper/lower training split designed to increase muscle hypertrophy while improving maximal strength.
Day 1: Lower (Monday)
Exercise
Sets
Reps
A
Conventional Deadlift
3
3
B
Barbell Back Squat
4
8
C1
Glute-Ham Raise
3
12
C2
Leg Extension
3
12
D1
Standing Calf Raise
3
20
D2
Hanging Leg Raise
3
20
Note: C1 and C2 designations mean that you superset or alternate between these two movements. Same with D1 and D2.
Day 2: Upper (Wednesday)
Exercise
Sets
Reps
A
Barbell Bench Press
3
3
B1
Dumbbell Bench Press
4
8
B2
Dumbbell Row
4
8
C1
Pushup
3
20
C2
Chin-Up
3
12
D1
EZ Bar Biceps Curl
3
15
D2
Cable Triceps Press Down
3
15
Day 3: Lower (Friday)
Exercise
Sets
Reps
A
Speed Front Squat
9
3
B
Romanian Deadlift
4
8
C
Walking Dumbbell Lunge *
4
8
D1
Leg Extension
3
12
D2
Leg Curl
3
12
E1
Seated Calf Raise
3
20
E2
Cable Crunch
3
20
* Walking Dumbbell Lunge — Per leg
Day 4: Upper (Saturday)
Exercise
Sets
Reps
A
Speed Bench
9
3
B1
Incline Barbell Bench Press
4
8
B2
Barbell Bent Over Row
4
8
C1
Dumbbell Fly
3
20
C2
Lat Pulldown
3
12
D1
Dumbbell Shrug
3
20
D2
Dumbbell Hammer Curl
3
15
D3
Dumbbell Overhead Triceps Extension
3
15
Remember, there isn't a single "best" set and rep scheme.
Virtually any set and rep scheme will work. Their effectiveness, though, depends on whether the goal you're trying to achieve is conducive to your training program as a whole.
Establish your goal (strength, speed, hypertrophy, etc.) and then determine the appropriate set and rep schemes you should emphasize.