by Emma Swanwick
Original Research
The measurement of power in swimming has previously been carried out using a number of different methods. Each method appears to produce differing wattages, the majority of which are far below those seen in athletes of a similar level in other sports. The aim of this paper was to define what is being measured, what it relates to, and to give appropriate titles to the “types of power” recorded.
American Journal of Sports Science and Medicine. 2017, 5(3), 57-63. DOI: 10.12691/ajssm-5-3-4
Pub. Date: November 21, 2017
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by Ryan D. Mitchell and Amada Podczerwinski
Original Research
Previous researchers observed that elite male cyclists’ performance improves with combined ingestion of caffeine and carbohydrate. We carried out this study to determine if similar outcomes would be observed in a group of cyclists varying widely in age and racing experience as well as gender. We administered carbohydrate with or without the addition of 6 mg/kg body weight caffeine in a counterbalanced blind manner to ten trained male and female cyclists in the fed state one hour prior to 20 minutes of steady-state (SS) cycling at 60% VO2max power followed by a simulated 10-mile time trial (TT). Ventilation (VE), rate of oxygen consumption (VO2), respiratory exchange ratio (RER), and rate of perceived exertion (RPE) were measured during the SS, whereas completion time, average power output, heart rate (HR) and RPE were measured during the TT. The addition of caffeine resulted in a significant reduction in completion time (1.9%) and increased the average power output (5.0%), as well as significantly higher heart rates during the TT (2.9%). We observed no significant differences in VE, VO2, RER, RPE, and HR during the SS between treatments. Our data shows that the ingestion of 6 mg/kg of caffeine in combination with a 7.5% carbohydrate solution in male and female cyclists in the fed state improves short duration time trial performance as measured by completion time and average power output. These findings can be of great value to cyclists across a wide range of age and experience.
American Journal of Sports Science and Medicine. 2017, 5(3), 53-56. DOI: 10.12691/ajssm-5-3-3
Pub. Date: November 02, 2017
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by Sakiko UKITA and Kaoru TSUYAMA
Original Research
In this study, we examined gender differences and age-related changes in toe muscle strength in childhood as well as the relationship between toe muscle strength and basic motor skills. The subjects included 288 children aged between 6 and 10 years who were enrolled in elementary school. Measurements were conducted for toe muscle strength, long-distance throw, 50 m running time, and standing long jump distance. Toe muscle strength develops with age throughout childhood; no differences were observed in toe muscle strength between girls and boys; however, a significant correlation was observed between toe muscle strength and each of long-distance throw, 50 m running time, and standing long jump distance. There was also a significant partial correlation (eliminating the influence of age) between toe muscle strength and long-throw distance, 50 m running time, and standing long-jump distance for both boys and girls. The results indicate that toe muscle strength tends to develop with age, but there are no gender differences. Results also suggested that toe muscle strength is significantly related to basic motor skills.
American Journal of Sports Science and Medicine. 2017, 5(3), 48-52. DOI: 10.12691/ajssm-5-3-2
Pub. Date: September 19, 2017
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by Ryan D. Mitchell and Caitlyn Crandall
Original Research
The purpose of this study was to determine the validity of a 15 minute field test of VO2max in competitive adult male and female 5k runners and analyze the factors that contribute to the VO2max of runners in the field versus on a treadmill. Nineteen trained, endurance runners completed a graded treadmill test and a 15 minute field test on a 400 m track (the Balke field test) to independently determine VO2max.We compared the data using a paired sample t-test, Pearson’s correlation, and multiple linear regression. Treadmill VO2maxof runners was significantly higher than the VO2maxdetermined by the 15 minute field test (56.9 +/- 5.3 ml/min/kg vs. 52.7 +/- 4.3 ml/min/kg, t(18) = 6.609, p = 000). We found a strong correlation when both treadmill pace at VO2max and treadmill VO2maxwere used as predictive factors for field VO2max (r2= 848, p = .000) with treadmill pace at VO2max having the strongest associative power in the correlation (β = .636, p = 001). The 15 minute field test is an adequate test of 5K race readiness, with the addition of treadmill test giving athletes and coaches an assessment of race fitness relative to aerobic capacity. In addition to treadmill VO2max, coaches and athletes must consider additional performance factors such as treadmill pace at VO2max, lactate threshold, running economy, motivation, etc. for the prediction of field or performance VO2max.
American Journal of Sports Science and Medicine. 2017, 5(3), 44-47. DOI: 10.12691/ajssm-5-3-1
Pub. Date: August 22, 2017
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