On June 16th, 2020 a high school football player in Mississippi and a high school soccer player in Kentucky dropped dead during the first two weeks of their team's summer workouts. And while at the time of writing this article the official cause of death has not been released publicly, one can only assume that it is similar to what happened at the University of Maryland in 2018 (where Jordan McNair died of Cardiac Arrest). These instances, as completely unfortunate as they are, can often be avoided through proper understanding of conditioning and how to prepare for sports.
Unfortunately, there is a stigma around training for sports, or even general fitness, that conditioning should leave you gasping for air or borderline vomiting for it to have been a good workout. This could not be farther from the truth.
Conditioning, by definition, is classified as "the process of training or accustoming a person or animal to behave in a certain way or to accept certain circumstances."
I have underlined the major key points because it stands to reason that conditioning is not running until you puke or pass out. It's a process of identifying the key circumstances in a sport and adapting the human body to show characteristics for it. For many sports, long runs, endless sprints with little rest times, or failure sets of body weight exercises.
To understand conditioning, we need to understand the body's three main energy systems and identify which is dominant for a few main sports:
Anaerobic - alactic: this energy system does not use oxygen to create energy and utilizes phosphocreatine to create muscle contractions, which then cause rapid movement. This energy system is used primarily in fast movements lasting less than 10 seconds, and causes a byproduct called lactate. This is a primary energy system used in baseball/softball, american football, and short duration Track/Field events, and takes about ten times the length of the movement to fully recover.
Anaerobic - lactic: This energy system uses lactate to create energy and create rapid muscle contractions for movements lasting up to ~60 seconds. High amounts of time spent in this energy system creates a build up of lactate, which is flushed out of the muscle tissue in the 0-60 minutes post exercise (and not what makes you sore). This is dominant in sports like volleyball, tennis, wrestling, or mid-duration Track events, and takes about five to ten times the duration of the movement to fully recover.
Aerobic: This is the energy system that utilizes oxygen for the creation of energy, and is one of the most efficient energy systems. However, it takes a long time to make energy via this system, and is responsible for the "less athletic" movements in sports (I use quotations, because it is a different type of athleticism, but often the kind that gets skipped over in highlight reels). This is dominant in sports like swimming, rowing, and cross-country, and takes one to two times the duration of the movement to recover.
Now, when choosing conditioning activities for each sport, it is important to understand the characteristics of each sport and what adaptation you want to create in the muscles. If you want the ability to move fast and create powerful movements, then you need to train consistently in an Anaerobic-alactic manner. This means short, fast movements like a five second sprint, followed by long rest periods are optimal for developing speed and power. Slower, longer runs with short rest time is would then be great for developing endurance and slow twitch dominant athletes.
When we condition athletes to be better at their sport, we have to take these things into consideration. We must also consider their current level of ability when planning rest periods and which exercises get used for conditioning. In a detrained state, such as what we find almost every athlete or human to be in after more than 3 straight months off, recovery and rest becomes an essential part of conditioning. The less "in shape" someone is the slower they recover between an exercise or drill. And if you lack adequate rest time for conditioning, you start to switch which energy system the body uses and therefore may condition athletes into the wrong type of energy system for the sport.
Additionally, conditioning to the point of nausea or vomiting that many glorify as being a "good workout", may in fact have two main negative circumstances. Sickness during exercise, often brought on by a high blood acidity level, is a negative consequence of exercise. Your lungs act as a gas exchange system, with the body needing to get rid of CO2 and replacing it with oxygen. But if it can't get rid of CO2 fast enough, it can lead to nausea and vomiting. This then brings us an additional negative consequence that is more psychological than physical: conditioning to hate exercise.
When you train to the point of sickness, you create a negative psychological association with exercise and training, which can keep an athlete from putting full effort into a workout or practice. This then can be interpreted by coaches or parents as laziness, when it really boils down to be a psychological defense mechanism from getting sick. Think about it this way:
If you ate a handful of wild berries that caused you to throw up, you're likely not going to eat wild berries again.
The same can happen for training when we train until the vomit point. Athletes don't want to do what makes them feel bad, even if training is something that will ultimately prepare them for future success in their sport.
To wrap it up, it may help to follow the following though process: Identify the energy needs of the sport, identify the current level of conditioning for an athlete/team, then make a plan that accounts for meeting both of those things where they are at.