Actigraphy: The Ambulatory Measurement of Physical Activity

Measurement is as fundamental to modern sport as it is to science. The outcomes of Olympic trials and competitions are sometimes determined by tenths or hundredths of a second. Athletic training typically entails performance measurement in order to guide and enhance training methods. Better performance is often its own reward – that is, observing improvements may strongly motivate competitive athletes. This chapter has several purposes, and correspondingly two major sections. The first purpose of this chapter is to introduce readers to actigraphy: what it is, available instruments, and basic methodological issues. This is accomplished in the first major section of this chapter. The second purpose of this chapter is to apply this information to sports. In the second section, I begin with circadian issues, since actigraphy can track activity level 24 h per day, seven days per week, 365 days per year. Subsequently, I will discuss nocturnal activity and sleep since athletes need to be properly rested. Following this, I will consider diurnal activity as training occurs during waking hours. This discussion will include high-resolution actigraphy to better understand behavioral topography in sports such as track and field, bowling, golf, skating, gymnastics, and skiing.