Continue to progressively overload the targeted muscle group or energy system, and you will continue to improve... for a little while.
Fail to properly modify your volume, intensity, and/or rest, and you will likely experience the dreaded plateau
Training should be specifically tailored for each individual such that the stimulus provides the appropriate amount of overload to elicit the desired response. Each individual responds to a given stimulus a little bit differently.
Performing the back squat for 3 sets of 5 repetitions @ 245 pounds may be just the right amount of overload to drive adaptation (gains in strength in this case) for you, but this would destroy a novice lifter, and it might feel like a warm-up for that one "manimal" that every unit has.
You should know that genetics and previous training play a large role in this. We can all get bigger, faster, and stronger, but we all respond a little bit differently to each training stimulus. If you’re upset that no matter what you do, you just can’t dunk a basketball, perhaps you should have chosen taller parents. In other words, each of us has a ceiling that limits just how far training can take us. The key is training in the manner that most effectively helps you reach your genetic potential.
STEP 1: CONDUCT AN ASSESSMENT
Each individual responds to a given stimulus a little bit differently. With that in mind, you’ve got to assess your current strengths and weaknesses. Do you have a strength deficit? What is your limiting factor on the leg tuck -- grip strength or the ability to stabilize the trunk? Answering these questions will help you determine where you need to spend your time. This is one of the reasons why the ACFT is such a huge improvement when compared to the APFT -- we can get a true assessment of comprehensive physical fitness. Take a look below at a potential ACFT "profile." Where should this individual focus their training? Keep in mind that your specific mission may influence the answer to this question... perhaps we know the demands of a certain environment or job -- should we intentionally bias our training towards lower-body muscular endurance if we know the mission will require dismounted patrolling in mountainous terrain? Finally, remember that this graph might not represent a single individual, but an entire squad, platoon, or company. An informed leader could take this information and tailor the unit's training in such a manner as to reduce the training deficit in the most needed areas.
STEP 2: MONITOR YOUR PROGRESS
What gets measured, gets managed. This is at the heart of the Army's new fitness test. Soldiers will train to the test. In doing so, many Soldiers will significantly increase their overall fitness, thus creating a more capable, resilient fighting force. Now that we're measuring meaningful performance indicators, it's time to set up a program to ensure we are trending in the right direction. Assess your progress no earlier than 8 weeks after the first assessment (if you are training in earnest, 8 weeks is about how long it should take to make measurable changes). Compare your performance on the first test with your performance on the second test. Hopefully you've started to decrease the training deficit.
While the tested Soldier does have a solid aerobic base (a great foundation), the initial assessment indicated a strength and power deficit (low deadlift and power throw), a less than average anaerobic capacity (slow sprint-drag-carry), and weak trunk strength and/or stability (low leg tuck). In order to become a more complete Soldier, he/she prioritized training in the muscular strength and anaerobic endurance domain. Compare the results from the first test with the results from the test 8 weeks later. Performance in the strength and anaerobic domain significantly increased, but aerobic performance took a few steps back. Depending on the particular demands of the given Soldiers' MOS and mission, he/she might now choose to dedicate equal training time to each of the components of fitness. While this type of concurrent training may not result in significant increases in performance in any one domain, it may contribute to slight or moderate increases across each domain. Ultimately, you must take responsibility for assessing your performance, developing a game plan, executing your training, and then re-assessing your capacity (Plan, Prepare, Execute, Assess -- sound familiar?).