Tuesday, July 22, 2014

Sport Based Youth Development and Health Promotion

Sport Based Youth Development and Health Promotion

Don Siegel

One of the goals of sport based youth development programs is health promotion. Given all that we have been hearing about the increasing prevalence of obesity in kids, and its associated co-morbidities such as type II diabetes, various cancers, cardiorespiratory diseases, and psychological stress, many have seen the involvement of youth in sports’ programs as a means to reverse, or at least, slow down such nefarious trends. Clearly, ramping-up physical activity levels in youth is a good thing, as it promotes caloric expenditures. Yet, sport is not a monolithic concept when it comes to caloric expenditures, in that substantial differences exist among activities, and in the intensities with which youth participate.

To help practitioners understand how activities differ, and the energy expenditure (EE) differences among activities, Table 1 lists a sample of youth sport/physical activities and their EE expenditures, corrected for age and pubertal status, for an 8-12 year old boy or a 8-11 year old girl weighing 99 lbs (Harrell et al., 2005). Within this table, 1 - MET may be interpreted as the metabolic equivalent of a child sitting quietly and processing oxygen at the rate of 3.5 milliliters per kilogram of body weight per minute. Calories are computed by multiplying a child’s weight in kilograms by an activity’s MET level and then using an adjustment factor for age and pubertal status (for the example given this factor = 1.71). As well, calories represent a unit of thermal energy, and as an approximation, it takes 3500 kcalories to burn 1 pound of fat.


Activity
Effort
METs
Baseball
Light
3.8
292
Baseball
Moderate
5.0
385
Baseball
Hard
6.3
485
Basketball
Light
7.2
554
Basketball
Moderate
8.2
631
Basketball
Hard
10.1
777
Bicycling
Light
4.7
362
Bicycling
Moderate
6.2
477
Bicycling
Hard
7.8
600
Cross Country Skiing
Light
7.0
539
Cross Country Skiing
Moderate
8.0
616
Cross Country Skiing
Hard
9.0
693
Dancing
Light
4.1
315
Dancing
Moderate
5.5
423
Dancing
Hard
6.9
531



Dodge Ball
Light
3.8
292
Dodge Ball
Moderate
5.0
385
Dodge Ball
Hard
6.3
485
Downhill Skiing
Light
5.0
385
Downhill Skiing
Moderate
6.0
462
Downhill Skiing
Hard
8.0
616
Golf
Light
3.0
231
Golf
Moderate
4.3
331
Golf
Hard
4.5
346
Gymnastics
Light
3.0
231
Gymnastics
Moderate
4.0
308
Gymnastics
Hard
5.0
385
Field Hockey
Light
6.0
462
Field Hockey
Moderate
8.0
616
Field Hockey
Hard
10.0
770
Horseback Riding
Light
2.5
192
Horseback Riding
Moderate
4.0
308
Horseback Riding
Hard
6.5
500
Ice Hockey
Light
6.0
462
Ice Hockey
Moderate
8.0
616
Ice Hockey
Hard
10.0
770
Jogging
Light
7.7
593
Jogging
Moderate
8.5
654
Jogging
Hard
9.3
716
Jump Rope
Light
6.2
477
Jump Rope
Moderate
8.8
677
Jump Rope
Hard
11.0
846
Kickball
Light
5.3
408
Kickball
Moderate
7.0
539
Kickball
Hard
8.8
677
Lacrosse
Light
4.8
369
Lacrosse
Moderate
6.4
492
Lacrosse
Hard
8.0
616
Martial Arts
Light
7.5
577
Martial Arts
Moderate
10.0
770
Martial Arts
Hard
12.5
962
Netball
Light
7.2
554
Netball
Moderate
8.2
631
Netball
Hard
10.1
777
Rock Climbing
Light
6.0
462
Rock Climbing
Moderate
8.0
616
Rock Climbing
Hard
11.0
846
Rollerblading
Light
4.9
377
Rollerblading
Moderate
6.5
500
Rollerblading
Hard
8.1
623
Rowing
Light
3.0
231
Rowing
Moderate
7.0
539
Rowing
Hard
12.0
923
Rugby
Light
6.6
508
Rugby
Moderate
8.8
677
Rugby
Hard
11.0
846
Soccer
Light
6.6
508
Soccer
Moderate
8.8
677
Soccer
Hard
11.0
846
Softball
Light
3.8
292
Softball
Moderate
5.0
385
Softball
Hard
6.3
485
Squash
Light
5.3
408
Squash
Moderate
7.0
539
Squash
Hard
8.8
677
Swimming
Light
8.4
646
Swimming
Moderate
9.9
762
Swimming
Hard
11.6
893
Table Tennis
Light
3.0
231
Table Tennis
Moderate
4.0
308
Table Tennis
Hard
5.0
385
Tag
Light
3.8
292
Tag
Moderate
5.0
385
Tag
Hard
6.3
485
Tennis
Light
5.3
408
Tennis
Moderate
7.0
539
Tennis
Hard
8.8
677
Touch Football
Light
6.6
508
Touch Football
Moderate
8.8
677
Touch Football
Hard
11.0
846
Ultimate Frisbee
Light
6.0
462
Ultimate Frisbee
Moderate
8.0
616
Ultimate Frisbee
Hard
10.0
770
Volleyball
Light
3.0
231
Volleyball
Moderate
4.0
308
Volleyball
Hard
5.0
385
Weight Lifting
Light
2.1
162
Weight Lifting
Moderate
2.8
215
Weight Lifting
Hard
3.5
269

What Can we Learn from Table 1 and Table 2?

Perhaps, the first things that these data show is that a child who engages in any of the sports and physical activities contained in the table expends significantly more energy than if they were sedentary. METS range from 2.1 – 12.5, with associated caloric expenditures ranging from 162 – 962 kcal/hr. From another perspective, engaging in any of the listed sports and physical activities, everything else being equal, leads to burning a pound of fat between 3.6 and 22 hours. In contrast, Table 2 shows the EE for this age group for an aggregate of sedentary activities. As one can see, these activities have MET values that range from 1 – 1.5, and caloric expenditures that range from 77 – 115 kcal/hr. Everything else being equal, it would take between 30 and 45.5 hours to burn a pound of fat in such activities.   

Table 2. EE for Selected Sedentary Activities

Activity
METs
kcalories/hr
Board Games
1.5
115
Math Test
1.5
115
Homework/Reading
1.3
100
TV Watching
1.0
77
Video Game (Sitting)
1.5
115

Consequently, as most people already know, when caloric expenditure is a goal, participating in a youth sport’s program or other physical activity makes sense. Such participation becomes especially effective when a child adheres to the recommendation of engaging in 60 minutes, or more, of physical activity each day, with most of that activity falling into the moderate – to vigorous level (i.e., > 3 METs). Extrapolating from Table 1, this would result in expending between 231 and 962 kcal/hour, and if a child participated 7 days a week in such activity, they would burn between 1617 – 6734 kcals in a week. Everything else being equal, this would result in burning a pound of fat from .5 to 3.1 weeks. Table 3 shows the time in weeks to burn 3500 kcals for selected activities, assuming that a youth participated in that activity for 1 hour a day, at a particular level, for each day of the week.

Table 3. Time to Burn 3500 kcal in Weeks

Activity
Level
Weeks to Burn 3500 kcals
Martial Arts
Hard
.5
Rowing
Hard
.5
Swimming Hard
Hard
.6
Rugby Hard
Hard
.6
Soccer
Hard
.6
Basketball
Hard
.6
Field Hockey
Hard
.6
Ice Hockey
Hard
.6
Touch Football
Hard
.6
Cross-Country Skiing
Hard
.7
Squash
Hard
.7
Tennis
Hard
.7
Ultimate Frisbee
Hard
.7
Lacrosse
Hard
.8
Downhill Skiing
Hard
.8
Baseball
Light
1.7
Softball
Light
1.7
Golf
Light
2.2
Rowing
Light
2.2
Volleyball
Light
2.2
Horseback Riding
Light
2.6
Weight Lifting
Light
3.1


Some Activities Burn more Calories than Others

As previously noted, most people think about youth sports as one entity, but Table 1 shows us that there are quite marked differences among activities with regard to EE. As well, we can also see that within activities, EE differs with regard to the effort a child expends in it while engaged. To illustrate this point, a child who plays golf with “light effort” (3 METs) would burn 231 kcal/hr while the same child engaged in martial arts at “high effort” would burn 962 kcal/hr, an approximately 4 fold difference! This is not to value one activity over another, as each has distinctive qualities, can teach unique developmental lessons, and may attract youth having diverse interests in different ways. However, if EE is an important goal, as it seems to be when promoting the notion that youth sports can be a meaningful intervention in our obesity epidemic, then recognizing that different sports and physical activities have markedly different caloric expenditures is important. This point is magnified in Table 3, which shows large differences in the time to burn 3500 kcals for different activities engaged in at high and low intensities.

Given the unique qualities associated with different activities, and their differing EE, practitioners should also focus on the manner in which youth engage in an activity. Over the years, Project Coach has had participants wear accelerometers to ascertain EEs in the various activities that we offer including soccer, volleyball, and basketball. From our observations, we have learned that how coaches structure and run activities can impact the percentage of time youth are playing “light”, “moderate” or “hard” within each sport. Some of the things that we have learned include: (a) reduce talk time to a minimum so that participants can maximize play time, (b) reduce transition time between activities within a session, (c) “tweak” activities to conform to the skill level of participants, and (d) maximize movement so that substitutes who may be waiting on the sidelines are more active on the sidelines.

First, we have learned that coaches often like to explain all aspects of a game or drill prior to having their players engage in it. Given that youth have a limited attentional span, and, often, minimal time to play, we recommend that coaches quickly convey the basics of an activity and instruct players on refinements as they play. Such a strategy not only forces coaches to understand their activity and players better, but also maximizes player’s level of activity within a session.

Second, over the years we have observed how transitioning from one activity to another one can eat up precious activity time. Often, equipment such as cones must to be placed, and/or participants need to be rearranged into different alignments for a subsequent game. Water breaks, which are important, can also devolve into disarray, making reconfiguring a team more difficult, resulting in lost movement time. By having coaches work in pairs many of these problems can be avoided. For example, as one coach leads the ongoing activity and brings it to an end, a second coach could have been setting up the playing space for the next activity and preparing for instructing and demonstrating how to get the team up and going as quickly as possible. As well, for water breaks, coaches can expedite things by providing guidance on how long players have to break, and use prompts to inform them when they should be ready for the next activity.

Third, we have learned that different developmental and skill levels can have a significant impact on how much activity a child gets if a program is too rigid in following the rules of a game. For example, we learned that younger children (e.g., grades 3-4) have difficulty-keeping balls in the air when playing volleyball, even when nets are lowered and beach balls are used to provide a larger and slower target. Consequently, we allow the ball to touch the ground while in play in order to keep a rally going, and kids engaged.  We also have added random exercise breaks into games in which a coach will blow her whistle, and everyone stops to do jumping jacks, or to change sides of the court quickly, and do sit-ups. Kids enjoy the rhythms and constant activity, in contrast to endlessly stopping play because of some mishap. We also have learned to “tweak” the way that we play basketball so that games have more continuous activity. For example, officials are lax in calling “traveling” or “incidental fouls” so that a greater amount of continuous play results. Officials also serve a coaching role to instruct players on these potential rules violations. Over time, kids move more and learn as they play, rather than being subject to more traditional sedentary lectures from their coaches, about rules and technical aspects of a game.

Finally, many games are structured where a smaller set of players get more activity than other players, or in which players are eliminated, for some period of time, because of a penalty that they may have incurred. In basketball, typically five players are on the floor at any one time, while five or more players are reserves. To enhance activity levels, we have asked our pairs of coaches to make certain that those who are “on the bench” are actually up on the sidelines practicing their passing, dribbling, and defense.  Or in games such as “Knockout” in soccer in which a player is sidelined when another player knocks their ball out of a specified area, that the “knocked-out” player can come back in the game after doing an activity such as ten jumping jacks. The idea in such situations is to creatively find ways for all kids to be active regardless of what their roles at the moment might be.

Summary

As we learn more about sports and physical activity programs for children, it is becoming increasingly evident that besides the fun and educational opportunities they provide, they can also be important in the crusade to reverse our obesity epidemic. However, we need to understand the diversity of activities encompassed by sports; one of which is the relative energy expenditures unique to different activities. Finally, as practitioners, we should be creative in maximizing the amount of movement contained in our activities by decreasing “lecture time” and “transition time”, “tweaking rules” to provide more continuity in play, and by finding ways to engage all of our players to be active during the time that we have with them.

References

Harrell, J. S., McMurray, R. G., Baggett, C. D., Pennell, M. L., Pearce, P. F., & Bangdiwala, S. I. (2005). Energy Costs of Physical Activities in Children and Adolescents. Medicine & Science In Sports & Exercise, 37(2), 329-336.


2008 Physical Activity Guidelines for Americans, Department of Health and Human Services,  available at: http://www.health.gov/paguidelines/guidelines/