July 2017 - Volume 49 - Issue 7

  • L. Bruce Gladden, PhD, FACSM
  • 0195-9131
  • 1530-0315
  • 12 issues / year
  • 6/81 in Sports Sciences
  • 4.141
​​​​​​​​​​​​​​​​​​​​​​This month I am drawing attention to three intriguing studies. First, Luetkemeier et al. investigated the effect of skin tattoos on sweat rate and sweat sodium concentration. These researchers recruited 10 college-age subjects who had a tattoo on only one side of their upper body. When chemically stimulated by a cholinergic agonist, tattooed skin generated about half as much sweat as non-tattooed skin. Sweat from tattooed skin also had a higher sodium concentration indicating lower sodium reabsorption. The age of the tattoos (2 months to 4 years) was unrelated to alterations in sweat rate or sodium concentration. This indicates that damage in sweating caused by the tattoo does not normalize quickly following the procedure. Whether or not a high heat load combined with a large proportion of tattooed skin would lead to inadequate cooling and increased core temperature is currently unknown.

Next, Madzima et al. engaged 33 breast cancer survivors in a 12-week full-body resistance training program, 2 days/week utilizing 10 exercises for 2 sets of 10 repetitions and a last set performed to complete fatigue at 65%–81% of their one repetition maximum (1RM). In 17 of the subjects, the resistance training intervention was also combined with a 20-g protein supplement (whey and casein blend), consumed twice a day. Although the protein did not provide additional benefits, increases in strength (up to 32%) and lean mass (+0.9 ± 1.0 kg), and decreases in fat mass (-0.5 ± 1.2 kg), and body fat percentage (-1.0% ± 1.2%) were observed. In conclusion, this training intensity (65%–81% of 1RM) improved lean mass more than has been previously reported in breast cancer survivors participating in a resistance training intervention.

Finally, Herrick et al. reported on three US Volleyball National Team members who underwent a comprehensive genetics evaluation as well as cardiac screening. As indicated by one of the cases, people with Marfan syndrome may not present with all of the typical clinical phenotype features. In this case, the subject was tall but had no other overt clinical features of Marfan syndrome. Only by performing a screening echocardiogram was an aortopathy identified. Genetic testing then confirmed the diagnosis of Marfan syndrome, and for this reason it was recommended that he cease playing competitive volleyball. Overall, these case evaluations on three athletes suggest that clinical screening combined with genetic testing in tall athletes may be warranted because it can lead to the identification of individuals with previously undiagnosed aortopathies who are at risk for life-threatening aortic dissections.​​

L. Bruce Gladden

School of Kinesiology
Auburn University