Time of Day Effects of Handgrip Fatiguing Protocol

The purpose of this study is to examine the effects of time of day on an intermittent handgrip fatiguing protocol. This protocol consists of repeated maximal effort isometric contractions using a handgrip dynamometer.

This study will consist of five visits. The first visit will consist of informed consent, questionnaires, demographics, and ultrasound images of the forearm. The second visit will consist of anthropometrics (height, weight, and body composition), followed by familiarization with the study protocol. The third, fourth, and fifth visits will be testing visits and will consist of the brief mood introspection scale, maximal voluntary contractions (MVC) with the handgrip dynamometer, the intermittent handgrip fatiguing protocol, and three recovery MVCs. Temperature and muscle tissue oxygenation will also be assessed via a skin temperature probe and near infrared spectroscopy (NIRS).

Visits 3-5 must be completed at different times of the day in a pre-determined randomized order. This may look like:
A) 9:00am, 2:00pm, 7:00pm
B) 2:00pm, 7:00pm, 9:00am
C) 7:00pm, 9:00am, 2:00pm

All visits will be separated by at least 24-48 hours. Each visit will take approximately 30-45 minutes.