一位 A. Magrini博士

部门

Exercise Science and Pre-Health Professions

位置

Assistant Professor

文章

• Journal of Strength and Conditioning Research
  Leland Barker, Jacob Siedlik, 一位 Magrini, 撒莱Uesato, 哈维王, 亚历克斯Sjovold, Garrett Ewing, John R Harry Currently, 随着落点高度的增加，降落过程中的偏心力-速度分布(eFVP)还没有研究, which may reveal an athlete's braking capacity and control strategies. 因此, 本研究的目的是评估随着落差高度的增加，双侧降落时的eFVP. 第二个目的是探索和确定eFVP与常见指标(如相对强度和跳跃性能)之间的相关关系. 整体, 19名来自该大学的休闲训练运动员完成了1次最大后蹲重复, countermovement jumps, 蹲跳, 减少跳跃, and drop landings from 0.3 to 1.52-m box heights in 0.15-m increments. 使用峰值降落试验的平均力和速度来生成eFVP. The mean linear eFVP was −6.65x + 14.73, and the mean second order polynomial eFVP was −1.37x2 − 25.84x + 0.17. 二阶多项式拟合数据效果较好，且效果较大(dunb = 1).05, p < 0.05). eFVP系数与强度和跳跃测量值之间无显著相关性. Future research could investigate how training can influence the eFVP. 着陆过程中产生的偏心力可能是一种独特的品质，需要特定的开发策略, such has fast or slow eccentric training. 2022
• Journal of Motor Behavior
  一位 Magrini, Ryan J Colquhoun, Matt C Ferrell, Sydnie R Fleming, 雅各布·莫塔, Jacob A Siedlik, Nick M Poidomani, Nathaniel DM Jenkins, 本研究考察了肌肉激活和运动单位数估计(MUNE)对年轻(YM)和老年(OM)男性早期自愿扭矩发展率(RTD)的影响. Thirty-two YM (n = 17; Age = 22 yrs) and OM (n = 15; Age = 74 yrs) volunteered to participate in this study. Early phase RTD (first 50 ms of a rapid isometric contraction; RTD50) and normalized surface electromyography (first 50 ms of muscle excitation; nEMG50) were recorded from the right quadricep muscle group. MUNE was examined from the right vastus lateralis. 多元线性回归分析显示，nEMG50对RTD50有显著影响，与年龄组无关(p≤0.001). nEMG50 had a significant effect on RTD50 in the OM group (p = 0.037). MUNE had no effect on RTD50 independent of age. 与年轻人相比，老年人可能更多地依赖于早期RTD收缩发作时的肌肉激活.
  54 2021
• Journal of Strength and Conditioning Research
  Masoud Moghaddam, Carlos A Estrada, Tyler WD Muddle, 一位 A Magrini, Nathaniel DM Jenkins, 这项研究比较了两种高强度间歇训练(HIIT)的效果, 10比5 vs. 一个20-10秒的工作休息比，对无氧和有氧表现. 34人被随机分配到10-5-HIIT组(n = 17)和20-10-HIIT组(n = 17)，完成6个周期的6项运动, 3 days a week for 4 weeks. 10-5- hiit以10秒:5秒的工作休息比进行，周期之间恢复1分钟, 而20-10- hiit以20秒:10秒的工作休息比进行，然后进行2分钟的恢复. Anaerobic (i.e., peak power [PP], anaerobic capacity [AC], anaerobic power [AP], and total work [TW]) and aerobic fitness (i.e., time to exhaustion [TE], absolute V̇o2max [A-V̇o2max], 采用训练前和训练后干预测量相对V值[R-V值]. A significant main effect time was observed for both 10-5-HIIT and 20-10-HIIT (p < 0.05) in PP (9.2%, 5.7%); AC (14.9%, 8.6%); AP (9.0%, 6.2%); TW (15.1%, 8.5%); TE (4.3%, 5.5%); A-V̇o2max (9.4%, 8.9%); R-V̇o2max (8.5%, 8.2%), respectively. In conclusion, 个人可以通过执行10-5 hiit来获得与20-10-HIIT相似的健康益处, despite exercising for 50% less total time. 高强度间歇训练被认为是一种“时间效率”的运动模式，可以减轻身体活动的最重要障碍, “lack of time.“10-5-HIIT和20-10-HIIT都可以在类似程度上诱导性能调整. 然而, because of shorter time commitment, 以10:5的工作休息比进行10:5 - hiit可以提供更短且同样有效的间隔. HIIT方案中的功能健身训练似乎与基于测功计的HIIT一样有益于改善无氧和有氧表现.
  35, p. 1685-1692 2021
• Clinical Parkinsonism & Related Disorders
  Kelley G Hammond, mitchell A Magrini, Jacob A Siedlik, C Scott Bickel, Marcas M Bamman引言 人们普遍认为，帕金森病(PD)患者中枢神经系统的病理生理变化会对运动功能产生负面影响. 然而，关于PD在骨骼肌上的病理信息知之甚少. 本研究的目的是确定疲劳等距膝关节伸展方案对PD患者和未受损老年人(OLD)使用诱发抽搐收缩的肌肉力学的影响。. 方法 在PD患者(66±9年)的疲劳过程中检测诱发抽搐收缩, n = 8) and OLD (65 ± 10 yr, n = 5). 参与者进行5秒最大等长自主股四头肌收缩，休息5秒，持续3分钟. Every 30-sec during rest intervals, 对股四头肌进行最大经皮电刺激，量化诱发的峰值抽搐扭矩(pTT)。, peak relaxation rate (pRR), and peak rate of torque development (pRTD). 结果 A large effect of voluntary fatigue (%decline) was observed (g = 1.58). There were no significant differences in pTT (p = 0.09; 95% CI:-3.6, 0.28) or pRR (p = 0.11; 95% CI:-31, 3.6). 然而, the slope decline of pRTD in OLD (-35.4 ± 24.7) was greater than PD (-11.5 ± 11.4; p = 0.03), 表明PD患者的骨骼肌与未受损的老年人相比不易疲劳. 结论 率, not the maximum capacity, 在疲劳的膝关节伸展过程中肌肉产生的扭矩受到PD的影响. 未来的研究有必要确定造成PD患者骨骼肌收缩特性差异和潜在肌纤维分布变化的机制.
  5 2021