Catching the detrain in football.

Why you have to monitor your conditioning program throughout the entire season

Football is a multi-component sport that depends on a number of energy sources to meet the strenuous physical demands of all the practices and games.

Every player, depending on his position and the demands of the particular game or practice, must: (1) possess an adequate cardio-respiratory capacity to meet both the short-term and long-term demands of the sport, and (2) must expend a certain amount of muscular energy in both a dynamic and static manner of varying intensity and duration.

Few other sports place such a demand on the athlete's ability to produce high levels of muscular power. The training regimen must necessarily focus on the development of strength, power, aerobic fitness, flexibility, and agility. The various benefits and metabolic adaptations associated with training are quite well documented in the literature.

The necessity of intense pre-season training is understood by all coaches. What generally isn't understood is the effect of detraining-periods of inactivity or decreased levels of activity in either the training routine or during the actual competitive season.

Though the effect of detraining is not well-documented in the research literature, a small body of evidence suggests that even short periods of inactivity may produce significant, but negative, alterations in physiological conditions and performance; that is, cause negative changes in maximum oxygen consumption (Max V[O.sub.2]), a decrease stroke volume output (SVO), smaller anterio-venous oxygen difference (A-V Diff.), and undesirable changes in muscular strength and endurance.

Conclusion: As a result, the many positive effects of training can be lost in a relatively short period of time after training is either stopped (as with injured players) or decreased in intensity.

The actual loss due to detraining will vary with the physiological systems involved and the specific time period in question, but the obvious end result is an impairment of the athlete's capacity to function at maximal levels of efficiency.

Detraining data from athletes involved in on-going competition such as football is even less available. Football has a relatively short, intensive competitive season and once the regular season commences, coaches usually spend less time on training and conditioning. Skill development and team execution tend to dominate the practice sessions.

The athletes are provided with an off-season training program and are expected to arrive at training camp in "good shape." It is usually assumed that the practice sessions will be able to maintain the specific fitness levels, but this is not always the case.

The typical football play represents only 5-10 seconds of maximum effort. From the physiological standpoint, a 60-minute football game is composed of 60 to 70 periods of high-energy movement.

Although there is a distinct division of labor among the playing positions, the game is generally played at maximum effort. For example, though aerobic fitness (which helps athletes recover between plays) may be more important for some players than others (offensive linemen vs. receivers), the demand for aerobic fitness can also change over the course of the game, depending upon the time remaining, the score, and the climatic conditions.

It is thus assumed that all players require a well-established base of fitness in every skill.

A CASE STUDY

A recent study conducted at the U. of Saskatchewan investigated possible detraining effects in a variety of the physiological and performance parameters that occur over the course of a season.

A combination of laboratory and football field tests were used to document these potential detraining changes among 29 varsity players, 21 of whom were starters.

The subjects represented the following positions: 6 defensive backs, 5 linebackers, 5 defensive linemen, 7 offensive linemen, 3 receivers, 2 running backs, and a quarterback.

The entire group was tested twice: over four days prior to start of training camp and, after 16 weeks, immediately following the season.

The laboratory tests utilized in the study included the Wingate 30-second anaerobic power test, a maximum oxygen consumption test (Max V[O.sub.2]), and static tests for knee extension and shoulder abduction strength as measured on a Cybex Isokinetic Dynamometer.

The field tests used included an IRM bench press, a vertical jump, a standing broad jump, a flexibility test, and a 20-yard shuttle run.

RESULTS

To analyze the pre-and post-season performances of the subjects, the players were placed into two groups - non-lineman and lineman groups.

The first group consisted of players whose responsibilities involved a great deal of running in practices and games, namely receivers, defensive backs, offensive backs, and a quarterback.

The second group consisted of players whose positions did not require as much running practices and games as did the non-lineman group.

Peak power - the power needed for the beginning of each play - is the most important indicator of power in football. An examination of mean values for anaerobic leg power, as measured by the Wingate test, revealed a slight decrease (0.80%) for the non-running group and a slight increase (1.78%) for the running group.

The vertical jump and long jump tests were used as a secondary measure of anaerobic power. Both groups showed a slight decrease in vertical jump mean scores (4.55% running and 2.81% non-running) and long-jump mean scores (1.15% running and 0.42% non-running).

Maximum oxygen consumption (Max V[O.sub.2]) actually showed a slight improvement, with the running group registering almost a 6% improvement and the non-running group slightly over 5%.

Muscle-strength testing showed that shoulder-abduction strength decreased over the course of the season by 11.5% for the running group and 6.3% for the non-running group.

Bench-press strength decreased for both groups by 8.1% for the running group and 4% for the non-running group, while leg-extension strength actually improved by about 4% for both groups.

DISCUSSION

When comparing the pre-season and post-season mean values of the various parameters for the two groups, it may initially appear that minimal detraining effects took place over the course of the season. But one must take care in interpreting the data and applying the results to the entire team, because mean values for the two groups were used in analyzing the data.

Football is a team game and the success of an individual play is dependent upon a maximum effort from all starting players. A weakness or a deficiency on the part of one or more players could cause the failure of the play.

When test scores (as opposed to mean scores) for the two groups are examined, it becomes evident that some players experienced significant detraining effects over the course of the season. For example, in the Cybex Isokinetic test for shoulder abduction, a starting linebacker showed a decrease of 19% while in the bench press test a starting offensive tackle demonstrated a 53% reduction.

When the individual scores for each test are examined, it becomes evident that some players (not necessarily the same ones) experienced significant detraining effects. This finding should be of great concern to the coach, especially when the success of a play is dependent upon the collective actions of everyone on the field.

A play may be unsuccessful at the point of attack because an offensive lineman did not have the power or strength to move a defensive lineman. Late in the game in a close contest, a wide receiver may no longer have the cardiovascular fitness level needed to reach the forward pass that would have won the game for his team.

SUMMARY AND CONCLUSIONS:

The results from the study could suggest a number of things.

First, the players who improved over the course of the season may not have arrived in the best physical condition, or perhaps the in-season practice sessions were strenuous enough to improve several of the basic elements in the conditioning process.

Second, since significant detraining effects appeared in some of the individual scores, it is essential for coaches to monitor their athletes and implement a maintenance program throughout the season. This becomes even more critical when you realize that the success of a play depends upon the all-out collective performances of all players.

Third, where laboratory-monitored tests are not feasible, some football-performance field tests may be quite suitable for monitoring the players physical condition.

Fourth, the possibility of detraining effects during a short competitive season deserves the attention of coaches and trainers in order to ensure the maximal performance capacities for entire season.

(V.E. Schneider Is an associate professor and assistant football coach, R.D. Bell is a professor in the College of Physical Education, and B.E. Arnold is an assistant football coach.)