Search Results

You are looking at 21 - 30 of 159 items for :

  • "treadmill walking" x
Clear All
Restricted access

David V.B. James, Linda J. Reynolds and Sara Maldonado-Martin

Background:

Heart rate variability (HRV) has been promoted as a noninvasive method of evaluating autonomic influence on cardiac rhythm. Although female subjects predominate in the walking studies, no study to date has examined the influence of the duration of a moderate intensity walking physical activity bout on HRV in this population.

Methods:

Twelve healthy physically active middle-aged women undertook 2 conditions; 20min (W20) and 60min (W60) bouts of walking on a treadmill. Resting HRV measures were obtained before (−1 h), and 1 h and 24 h after the walking bouts.

Results:

Mean NN interval (ie, normal-to-normal intervals between adjacent QRS complexes) was significantly lower (P = .017) at +1 h in W60 (832, 686−979ms) compared with W20 (889, 732−1046ms). A borderline main effect for time was observed for both the SDNN intervals in W60 (P = .056), and for low frequency (LFabs) power in W60 (P = .047), with post hoc tests revealing a significant increase between −1 h (51, 33−69 ms and 847, 461−1556 ms2) and +1 h (65, 34−97ms and 1316, 569−3042 ms2) for SDNN and LFabs power, respectively, but no increase at +24h compared with −1 h.

Conclusions:

It appears that a walking bout of 60 min duration does alter cardiac autonomic influence in healthy active women, and this alteration is not evident after 20 min of walking. Given the rather subtle effect, further studies with larger sample sizes are required to explore the nature of the changes in cardiac autonomic influence following a prolonged bout of walking.

Restricted access

Christopher A. Zirker, Bradford C. Bennett and Mark F. Abel

We examined how the application of a forward horizontal force applied at the waist alters the metabolic cost, kinematics, and external work of gait. Horizontal assist forces of 4%, 8% and 12% of a subject’s body weight were applied via our testing apparatus while subjects walked at comfortable walking speed on a level treadmill. Kinematic and metabolic parameters were measured using motion capture and ergospirometry respectively on a group of 10 healthy male subjects. Changes in kinematic and metabolic parameters were quantified and found similar to walking downhill at varying grades. A horizontal assist force of 8% resulted in the greatest reduction of metabolic cost. Changes in recovery factor, external work, and center of mass (COM) movement did not correlate with changes in metabolic rate and therefore were not driving the observed reductions in cost. The assist force may have performed external work by providing propulsion as well as raising the COM as it pivots over the stance leg. Assist forces may decrease metabolic cost by reducing the concentric work required for propulsion while increasing the eccentric work of braking. These findings on the effects of assist forces suggest novel mobility aids for individuals with gait disorders and training strategies for athletes.

Restricted access

Mark Elisabeth Theodorus Willems, Mehmet Akif Şahin and Matthew David Cook

Intake of the catechin epigallocatechin gallate and caffeine has been shown to enhance exercise-induced fat oxidation. Matcha green tea powder contains catechins and caffeine and is consumed as a drink. We examined the effect of Matcha green tea drinks on metabolic, physiological, and perceived intensity responses during brisk walking. A total of 13 females (age: 27 ± 8 years, body mass: 65 ± 7 kg, height: 166 ± 6 cm) volunteered to participate in the study. Resting metabolic equivalent (1-MET) was measured using Douglas bags (1-MET: 3.4 ± 0.3 ml·kg−1·min−1). Participants completed an incremental walking protocol to establish the relationship between walking speed and oxygen uptake and individualize the walking speed at 5- or 6-MET. A randomized, crossover design was used with participants tested between Days 9 and 11 of the menstrual cycle (follicular phase). Participants consumed three drinks (each drink made with 1 g of Matcha premium grade; OMGTea Ltd., Brighton, UK) the day before and one drink 2 hr before the 30-min walk at 5- (n = 10) or 6-MET (walking speed: 5.8 ± 0.4 km/hr) with responses measured at 8–10, 18–20, and 28–30 min. Matcha had no effect on physiological and perceived intensity responses. Matcha resulted in lower respiratory exchange ratio (control: 0.84 ± 0.04; Matcha: 0.82 ± 0.04; p < .01) and enhanced fat oxidation during a 30-min brisk walk (control: 0.31 ± 0.10; Matcha: 0.35 ± 0.11 g/min; p < .01). Matcha green tea drinking can enhance exercise-induced fat oxidation in females. However, when regular brisk walking with 30-min bouts is being undertaken as part of a weight loss program, the metabolic effects of Matcha should not be overstated.

Restricted access

Kirsten Tulchin, Michael Orendurff, Stephen Adolfsen and Lori Karol

Multisegment foot models provide researchers more-detailed information regarding foot mechanics compared with single rigid body foot models. Previous work has shown that walking speed significantly affects sagittal plane ankle motion. It is important to distinguish changes in intersegment foot mechanics following treatment that are due to clinical intervention versus those due to walking speed alone. Foot and ankle kinematics were collected on 24 adults walking at 5 speeds. Significant differences were seen at the ankle using a single rigid body foot model, as well as at the hindfoot and forefoot using a multisegment foot model, with all motions exhibiting a shift toward plantar flexion and decreased stance time with increasing speed. When evaluating foot mechanics using a multisegment foot model across groups or conducting intrasubject comparison over time/treatments, it is imperative that walking speed be accounted for or controlled.

Restricted access

Anna M. Ifarraguerri, Danielle M. Torp, Abbey C. Thomas and Luke Donovan

treadmill walking by reducing the lateral plantar pressure of their injured limb in response to receiving real-time video feedback. We hypothesized that, in response to real-time video feedback, participants with CAI would be able to decrease peak pressure and pressure-time integral on the lateral aspect of

Restricted access

Yoav Gimmon, Hisham Rashad, Ilan Kurz, Meir Plotnik, Raziel Riemer, Ronen Debi, Amir Shapiro and Itshak Melzer

hands free to swing; there were no handrails on the treadmill. Familiarization with the treadmill was achieved for each subject by 4–7 min of walking prior to data collection. To prevent injury if loss of balance occurred during the treadmill walking, the subject wore a loose safety harness that could

Restricted access

Mhairi J. MacDonald, Samantha G. Fawkner, Ailsa G. Niven and David Rowe

, difficult to accurately extrapolate step rate corresponding to moderate and moderate- to vigorous-intensity walking, due to the different intensity markers used and lack of direct assessment of energy expenditure. A major limitation with several of these studies is the assumption that treadmill walking is

Restricted access

Mustafa M.O. Elhadi, Christina Z. Ma, Duo W.C. Wong, Anson H.P. Wan and Winson C.C. Lee

treadmill walking at any time they requested. Gait analysis and subjective assessments were conducted (1) before treadmill walking, (2) after the first 30-min session of treadmill walking, and 3) after the second 30-min session of treadmill walking. Subjects walked in self-selected comfortable speed in both

Restricted access

Alexander H.K. Montoye, Jordana Dahmen, Nigel Campbell and Christopher P. Connolly

alternate body location. In a previous study, Connolly et al. ( 2011 ) examined accuracy of four hip-worn PA monitors (3 pedometers, 1 accelerometer) for step counting during treadmill walking in second and third trimester pregnant women, finding that only two of the devices (both pedometers: New Lifestyle

Restricted access

Elroy J. Aguiar, Zachary R. Gould, Scott W. Ducharme, Chris C. Moore, Aston K. McCullough and Catrine Tudor-Locke

promoted as a simple and practical method for gauging intensity in the free-living setting. 8 , 9 We previously described the calibration of cadence–intensity thresholds (ie, cadence values associated with increasing levels of intensity in a sample of young adults [age 21–40 y] during treadmill walking