Studies suggest women athletics influences change in bone and body composition (3, 6, 8, 9, 11, 13). Furthermore, these changes may be sport-specific (2-5, 8, 10, 11, 13). Every sport has different approaches to training because each sport has different physical requirements and performance needs (2, 5, 8, 11, 13, 14). Significant differences have been found in total body bone mineral density (BMD) among sports (2). BMD has been associated with sport-specific mechanical loading, bone strain, total body mass and lean mass (1, 3-5, 10, 11, 14). Weight-bearing physical activities, such as sports, are noted to promote bone density (1-3, 9, 10). Attaining optimal bone density during a woman’s early twenties is an important time (2, 12). Therefore, early sports participation can help reduce risk of osteoporosis later in life (7, 12). Overall, female body type adaptations to their sport can be beneficial to their health and fitness (7).

Though there are various reports on how sports effect body composition, there is little consistency (2). So, it is difficult to take results from one study and formulate accurate real-world assumptions. One study set out to characterize in- and off-season effects on body composition, as well as build a sense of reference and consistency for future research and athletic personnel.

Let’s take a look at their science

The study investigated bone and body composition values during 3 seasonal periods (off-season, preseason and postseason) for 67 female athletes from 5 different sports (softball, volleyball, basketball, swimming, and track jumpers and sprinters).

Using specialized scans, the study evaluated bone and body composition based on the following parameters:

  • Total body mass (TM)
  • Lean mass (LM)
  • Fat mass (FM)
  • Percent body fat (%BF)
  • Bone mineral content (BMC)
  • Bone mineral density (BMD)
  • Arm BMD
  • Leg BMD
  • Pelvis BMD
  • Spine BMD

What did they find?

Several conclusions were inferred from this study. Overall, comparisons showed bone measurements of swimmers were lower than athletes from all other sports for all seasonal periods. Also, track jumpers and sprinters showed lower percent body fat and fat mass compared to all other sport athletes for all seasonal periods. (2)

Basketball and volleyball athletes had unique results as well. Both groups of athletes showed statistically similar results in several variables, generally at high values scores. Meanwhile, values for baseball athletes, generally lied in between all other athletes. (2)

To get a general idea of the study’s results, take a look at the graphic below. The graphic is meant to generalize values for all 5 sports and give an idea of how each sport placed. This does not represent exact values or statistical significance. Please refer to the publication for exact statistics.

Bone and body composition results found per seasonal period were as follows:

Off Season Results

On the lower end for TM, FM, and %BF values were jumpers and sprinters compared to the other athletes (2). Which can make sense, as track athletes typically want to be lean due to the nature of their sport. Most likely, these athletes continue to try and maintain that physique while off season.

Basketball and volleyball athletes showed the highest values for TM, LM and leg BMD. In fact, the basketball athlete values were significantly greater compared to softball and track athletes. As well, BMD and BMC were significantly greater in basketball than softball athletes. (2)

Preseason Results

Significantly lower bone measurements in all bone sites were found in swimmers compared to the other athletes. This may be due to the fact the buoyant force of water reduces bone stress. Meaning, there is little stimulus for increasing BMD values. (2)

Track athletes comparatively had the lowest values of TM, FM, and %BF to other sport groups.  (2)

Basketball and volleyball athletes comparatively had the highest values of LM, with basketball athletes having significantly greater LM than softball, swimmers and track athletes. (2)

Postseason Results

Again, swimmers measured the lowest in several variables: BMC, BMD, leg BMD, pelvis BMD, and spine BMD. Track jumpers and sprinters had the lowest values in %BF and FM. (2)

Basketball athletes, again, showed higher values in TM and LM. Their TM values were significantly greater than swimmers and track athletes, whereas their LM values were significantly greater than softball and track athletes. (2)

Only spine BMD was significantly different among the 3 seasons. (2)

So, what can we put together?

Significantly lower BMD in swimmers was found in pre- and postseason (the study was unable to evaluate swimmers’ off-season). Similarly, other studies found significantly lower bone mineral density values in swimmers compared to other sports, such as basketball, volleyball and gymnastics (3, 14). In swimming there is no high impact loading on the athletes, and though they experience forceful muscle contractions (2, 14), this may explain the low BMD values in swimmers. This suggests sports or training that include high impact loading and high rates of bone strain are vital for better bone development (1, 3-5, 10, 14).

TM and LM are suggested to correlate with BMD values (4). A 2006 study reported women with high TM and LM values, participating in high impact sports, had the highest BMD values (4). This suggests athletes with higher TM and LM values can demonstrate greater force and strains on bone which leads to greater osteogenic response (2). However, in this study, track athletes, while having similarly high values of BMD with basketball and volleyball athletes, had low TM and LM values (2). This outcome may be a result of the study using sprinters and jumpers to represent track athletes. While track athletes desire to be lean and fit, sprinters and runners do experience similar actions to basketball and volleyball athletes. Athletes in respective sports run and jump frequently. These similarities may explain why selected track athletes showed similar BMD values with basketball and volleyball athletes – yet differed in TM and LM values (2).

Though swimmers were measured on the lower side for LM, FM, and %BF, the values were statistically similar to other sport athletes (2). This suggest athletic swimming still allows for muscle development and proper maintenance of body fat (2).

What does this tell us about bone health and body composition?

What this study tells us is both bone and body composition can be sports-specific – which makes sense. It is vital for sprinters and jumpers to have low FM and %BF in order to be competitive and optimize performance (2). Furthermore, this study suggests softball, basketball and volleyball athletes share similar body compositions due to similar values in FM, %BF, and TM (2). These sports do share similar qualities of play: need for endurance, upper body strength, short sprints. Therefore, it is reasonable to imply athletes from these sports may share similarities in body structure. Swimmers had lower bone values, possibly because they experience the least amount of resistance in their sport. This suggests it is important to include high-impact loading activities into a swimmer’s training to promote bone health and development (2).

This study also found significant shifts in bone and body composition between off-season and preseason, as well as off-season and post season (2). For example, softball athletes had significantly lower BMD values compared to basketball athletes during off-season (2). However, after preseason training, there was no longer a significant difference between the 2 athlete groups (2). This means that the training structure was sufficient enough to stimulate an increase in BMD values (2). However, after playing through the season, softball athletes again had significantly lower BMD compared to basketball athletes (2). What this tells us is that it is important to continuously measure and re-evaluate an athlete.

How can Sportavida help?

As athletes progress through the seasons of competition, their bone and body composition fluctuate. Therefore, in order to make appropriate assumptions on how the season has affected their body, it is important to scientifically measure the physiologic processes. Sportavida can test athlete saliva and help monitor how training, in- and off-season activities are affecting the body. Provided these informational reports, athletes, trainers, coaches etc. can evaluate athlete’s readiness to play and tailor an individual’s training plan. This provides individuals to make decisions based on personalized data – a solution to general assumptions.

 

 

 

 

REFERENCES

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  2. Carbuhn, A. F., Fernandez, T. E., Bragg, A. F., Green, J. S., & Crouse, S. F. (2010). Sport and training influence bone and body composition in women collegiate athletes. The Journal of Strength & Conditioning Research, 24(7), 1710-1717.
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