The terms complex and contrast training are often used interchangeably, however, there are distinct differences between these two training methods.
Complex training refers to alternating a high-load exercise with a lighter load power exercise, for example:
A1: Back Squat
A2: Box Jump
Whereas contrast training refers to contrasting heavy and light loads, performing all high-load strength exercises at the beginning of the session, followed by lighter load power exercises at the end, for example:
A: Back Squat
B: Good Morning
C: Broad Jump
Both methods are common place within a decent strength and conditioning plan, or at least they should be. However until now it was not clear which method is the best exercise sequence is to achieve the greatest performance adaptations.
Cormier, P. et al. (2020) recently investigated the effects of complex and contrast training on lower-body strength, vertical jump, sprinting, and change of direction ability.
Generally, both methods significantly improved neuromuscular performance. Likely because both methods utilised various loads along the force- velocity spectrum (more to be explained on this at a later date). However, there was a trend for complex training to be slightly more effective.
Large improvements where identified in vertical jump, sprint times and change of direction in the group using complex methods. Both methods helped elicit improvements in strength.
Personally, I really like the use of contrast training. In fact, I use it in almost every session with my more advanced athletes. Here is an example:
A1: Barbell Hip Thrust (4 sets of 6-8 reps at 75% 1RM):
A2: Rear Foot Elevated Split Squat (4 sets of 4-6 reps per leg at 60% 1RM):
A3: Alternating Bounds (4 sets of 20m)
Caution is taken as not to perform too much heavy strength work, as it can fatigue the neuromuscular system reducing the outputs of the lower load power exercises, hence the reason sub maximal loads are used in the examples above.
I will add, that the main reason I use contrast training with my more advanced athletes is that fatigue tends to kick in a little earlier with those with younger training ages, reducing the output during the more explosive / dynamic movements.
In the case of less advanced athletes, I may consider using the complex method, however I typically have them perform the explosive movements first, contrary to the traditional way of piecing the sequence together.