ABSTRACT
In resistance training squats are often used to strengthen the muscles of the lower extremities and core muscles. There are two common forms of squats that use a barbell for loading, the back squat and the front squat. The technique and loading of each squat differ markedly. However, the energetic demands on the muscle between the two forms are not well understood. The purpose of this study was to investigate the difference in energy demands between front and back squats by measuring the change in skeletal muscle oxygen saturation (SmO2) through the use of near infrared spectroscopy (NIRS). METHODS: Eleven resistance trained individuals, (5 female, 6 male) with an average age of 23.7 ± 1.4, completed 3 sets of 15 repetitions at 70% of their 1-RM weight for both back and front squats. Skeletal muscle oxygen saturation (SmO2) of the vastus lateralis was measured using a wireless NIRS device. RESULTS: The ΔSmO2 was not significantly different between back and front squats but was different between sets 1-3 (44.76 ± 3.24% vs. 55.19 ± 2.75% vs. 56.30 ± 2.63%), main effect p ≤ 0.0001. The recovery of SmO2 was significantly different between back (42.5 ± 3.4 sec) and front squats (30.9 ± 2.8 sec), main effect p ≤ 0.05. CONCLUSIONS: The findings of this study suggest that the energetic demands placed on the vastus lateralis during both front and back squats are similar with a slower recovery of energetics in the back squat.
ABSTRACT
BACKGROUND: The use of smartphone applications to monitor heart rate has become increasingly popular. However, there is limited research available on the validity of these applications. The purpose of this study was to examine the accuracy of a free heart rate monitoring application on two smartphone platforms while at rest and during moderate intensity exercise. One heart rate monitor application was chosen for two different technological platforms. METHODS: Twenty-four adults aged 18 and older (six males, 18 females) were randomly assigned a platform. Two groups were formed based on the platform being utilized. Both groups were monitored using an electrocardiograph (ECG) and the smart phone application. Heart rate for each participant was recorded while seated before exercise, and during moderate intensity exercise on an elliptical machine. Measurements were recorded in one-minute intervals. RESULTS: Data was analyzed using correlations and t-tests between platforms. All data was analyzed for both resting and exercise heart rate averages. There was no significant difference in heart rate while seated, t-test (-1.33; P=0.197) nor exercise heart rate, t-test (-1.54; P=0.142) when comparing means of the two platforms to an ECG. CONCLUSIONS: The applications chosen for both platforms to monitor heart rate were found to be fairly accurate, especially at rest. There are small user adaptations for monitoring heart rate, but heart rate applications provide a low-cost and efficient method for non-medical heart rate tracking. Future research should investigate the difference in accuracy for skin tone, ethnicity, race, hand size, and callosity of fingertips.
