One of the most rewarding aspects of coaching a beginner or deconditioned athlete is watching how quickly fitness can improve. Early in a training program, almost every appropriate training stimulus produces noticeable results.

I recall coaching an athlete from virtually ground zero to a 10-minute mile, and then progressing to a sub-7-minute mile as an age-group athlete in a single season. That is a tremendous amount of progress for an athlete over 40. Of course, individual results vary, but beginners often experience dramatic improvements during their first season of structured training.

The challenge comes when an athlete expects that rate of improvement to continue indefinitely.

It is easy to assume that if you continue putting in the time and doing the work, your performance will continue to improve at the same rate. Unfortunately, human physiology doesn't work that way. As an athlete becomes fitter and more experienced, physiological limitations become increasingly important. Gains become progressively smaller and harder to achieve.

One thing is certain: the faster you get, the harder it is to get faster.

Perhaps the greatest challenge for a coach is finding another few percent of performance in an athlete who is already highly conditioned and experienced.

Beginners Respond Quickly to Training

When an athlete begins training from a deconditioned state, virtually any appropriate training stimulus can produce results. For an endurance athlete, establishing basic aerobic fitness and the ability to complete a short race should initially be the primary goals.

A beginner should progress gradually toward that first race as the body adapts to the increasing training load. One of the most common mistakes new athletes make is doing too much too soon or training without a consistent plan. The result is often the first overuse injury.

Even a basic beginner training plan can help prevent this, provided that training volume increases progressively and regular recovery is included.

There is another important consideration: the body's physiological systems do not all adapt at the same rate.

Aerobic fitness may improve relatively quickly, while connective tissue can take considerably longer to adapt. Tendons, ligaments, bones, and other supporting structures need time to accommodate increased training stress. This becomes especially important for masters athletes, who may be capable of producing considerably more cardiovascular stress than their connective tissues are prepared to handle.

Fitness can improve faster than the body can safely support it.

From Completing to Competing

A large number of athletes are perfectly happy to remain at the "complete versus compete" level. There is absolutely nothing wrong with that. In fact, completing races without constantly chasing faster times may be a very balanced approach to fitness, health, and long-term sustainability.

But athletes who want continued performance improvement have to consider considerably more than simply adding mileage or training harder.

Once a solid aerobic endurance base has been established, other components of athletic performance may be incorporated into a training program. Depending on the athlete and sport, these can include:

• Strength training
• Peak power
• Aerobic capacity
• Lactate threshold training
• Strength endurance
• Anaerobic repeatability
• Sport-specific strength
• Plyometric training
• Speed and movement economy

The challenge is that an athlete cannot effectively emphasize everything at once.

Only a limited number of training objectives can receive significant attention during a particular training phase or macrocycle. Try to develop too many qualities simultaneously and the result may be that none of them receives enough stimulus to produce a meaningful adaptation.

That requires planning.

For a highly trained athlete, effective performance development may require thinking months—or even an entire season—ahead. Training has to become more specific, deliberate, and precise as the athlete becomes more advanced.

Why Successful Training Eventually Stops Working

Another important training principle is that what worked successfully in the past may not continue to work in the present.

Athletes are creatures of routine. If a particular workout or training program produced a breakthrough last season, it is perfectly logical to repeat it the following season.

The problem is that the body adapts.

Continually targeting the same physiological system can eventually produce a plateau. An athlete may continue performing the same workouts year after year, wondering why the results aren't improving.

Training adaptation requires an appropriate imbalance between stress and recovery. Once the body has adapted to a particular stimulus, that same stimulus may no longer provide enough of a challenge to create additional improvement.

This doesn't necessarily mean training harder. Sometimes it means training differently.

Continued athletic development may require a change in training volume, intensity, exercise selection, energy-system emphasis, recovery strategy, or sport-specific work. It may even require a completely different approach from what produced success in the past.

This is where an objective outside perspective can be extremely valuable.

A coach can sometimes identify a limitation that an athlete cannot see from inside their own training program. For an experienced athlete who has already developed a high level of fitness, finding that overlooked limitation may be the key to another few percent of performance.

Fitness Isn't the Whole Performance Equation

Fitness is only one part of athletic performance.

Nutrition, pacing, mental skills, injury prevention, technique, and movement economy can all have a substantial impact on race performance. In some cases, one of these non-fitness factors can become the primary limiter.

Speed skill and economy are particularly important.

An athlete may become significantly fitter without becoming proportionally faster if inefficient movement patterns prevent them from translating that fitness into performance.

Consider a few examples:

A runner who consistently runs with inefficient stride mechanics may become aerobically stronger without fully capitalizing on that fitness.

A cyclist who relies heavily on muscular force rather than developing efficient pedaling mechanics may have excellent cardiovascular fitness but struggle to turn that fitness into speed.

A swimmer can develop tremendous aerobic capacity while continuing to lose time through inefficient technique and excessive drag.

Fitness gets you to the starting line. Economy helps determine how much of that fitness you can actually use.

At the highest levels of competition, very small improvements in economy can make a meaningful difference. When athletes are already operating close to their physiological limits, saving a small amount of energy with each stride, pedal stroke, or stroke can accumulate into meaningful time over an entire event.

Running Economy and Sport-Specific Technique

Running is a particularly interesting example because most people receive very little formal instruction on how to run efficiently.

Most athletes simply start running.

Over time, they develop their own movement patterns. Some are relatively efficient, while others may create unnecessary energy expenditure or mechanical stress.

Running economy can be influenced by factors such as stride mechanics, cadence, strength, mobility, coordination, and neuromuscular training. Developing better movement patterns is not simply a matter of being born with good form. Technique can be practiced and trained.

The same principle applies across endurance sports.

Highly trained athletes don't necessarily need dramatically more fitness. They may need to become more efficient at using the fitness they already possess.

Is There a Point of Diminishing Returns?

Eventually, age catches up with all of us.

As we age, several physiological changes tend to occur, including reductions in VO2 max, increases in body fat, and declines in muscular strength. However, regular training can mitigate some of these changes and allow athletes to maintain a surprisingly high level of performance well into their 40s, 50s, and beyond.

We have all seen the "old salt" beating the spandex off athletes 20 years their junior.

I've coached athletes over 55 who were still setting personal records. While that isn't typical, it demonstrates an important point: age does not automatically determine how much an athlete can accomplish.

The combination of training history, genetics, recovery, nutrition, technique, strength, body composition, and lifestyle all influence performance.

There is also an important distinction between reaching a physiological limit and failing to address an existing limiter.

It is unusual to find an athlete who has absolutely nothing left to improve. There is often some component of training or performance that can be addressed—whether it is aerobic capacity, strength, technique, economy, pacing, recovery, nutrition, or mental skills.

How Far Can You Take Your Training?

No one really knows their true athletic potential.

There are undoubtedly genetic and physiological limits, and individual athletes will respond differently to the same training program. But the closer an athlete gets to their potential, the more important it becomes to identify the specific factors limiting further improvement.

Beginners can often improve simply by training consistently.

Advanced athletes don't have that luxury.

The highly trained athlete has to become increasingly precise about what to train, when to train it, how much training to apply, and when to recover.

The gains may become smaller, but that doesn't necessarily make them less meaningful.

Finding another minute, another watt, another second, or another few percent of performance can become an incredibly rewarding challenge.

How far can you take your training?

No one really knows what their true potential is.

There is only one way to find out.

The real fun is getting there.

Matt Russ enjoyed a professional coaching career spanning over two decades of working with professional endurance athletes. His athletes have achieved numerous regional, national, international and championship titles under his direction. Matt achieved the highest level of licensing by both USA Triathlon and USA Cycling, and was a licensed USA Track and Field Coach. His accomplishments include being named "Team USA" Coach for the 2011 Beijing World Championship. Head Coach and founder of The Sport Factory, a USA Triathlon Certified Performance Center, he has authored many articles on a wide variety of endurance related topics.