As usual, I am highlighting three studies in this month's issue of MSSE® (February 2018). In the first article, Kirkham et al. examined how women with breast cancer adhered to the frequency, intensity, time, and type (FITT) principle with supervised exercise consistent with recommendations. The program was concurrent with cancer treatment (chemotherapy ± radiation) and continued for 20 weeks following treatment. Frequency (i.e., attendance) decreased with increasing chemotherapy dose, but was higher during than after treatment. During treatment, the primary attendance barriers were cancer-related (e.g., feeling unwell, medical appointments) and were life-related after treatment (e.g., work, vacation). Adherence to the resistance prescription was poor both during and after treatment. Overall, individualization and flexibility in exercise prescriptions and behavioral strategies to support adherence appeared especially important for later chemotherapy cycles, after treatment completion, and for resistance exercise.
In the second highlight, Santtila et al. investigated changes in physical fitness and anthropometry of 627,142 young men entering the military service in Finland during the years 1975–2015. Weight gain had slowed in the last ten years but a significant number were still overweight. Maximal endurance capacity, measured as distance run in 12 minutes, decreased on average by 337 meters, and the proportion of poor test results increased sevenfold between 1980 and 2015. There was also only a fourth as many excellent test results. Changes in muscle fitness were similar but occurred later, during the years 1990–2010. More initiatives encouraging young men to increase their daily physical activity are needed to prevent this increasing trend of poor physical fitness and overweight.
Finally, Pethick et al. examined the influence of caffeine ingestion on the fatigue-induced loss of knee extensor torque complexity during submaximal contractions. Their previous work had shown that the "complexity" of torque output (the structure of torque fluctuations) declines during fatiguing contractions, a phenomenon previously associated with aging and disease states such as Parkinson's. They also previously suggested that peripheral fatigue was largely responsible for the fatigue-induced loss of torque complexity. However, use of caffeine ingestion in their current work revealed the loss of complexity is blunted in the absence of changes in peripheral fatigue, suggesting contribution of central mechanisms. In addition to reaffirming that caffeine can be ergogenic, this work also reveals, for the first time, caffeine's subtle influence on motor control processes as the neuromuscular system fatigues.
L. Bruce Gladden
School of Kinesiology