The aim of the present project is to compare the acute and chronic effect of stair descending versus stair ascending exercise on muscle damage and performance in elderly males with chronic heart failure.
Study design: Twelve elderly males with chronic heart failure, New York Heart Association class I-II, will participate in this study. Participants will be allocated into two equally-sized groups: a stair descending group (n = 6) and a stair ascending group (n = 6). At the beginning of the study, the volunteers will perform an acute bout of stair descending or stair ascending exercise on an automatic escalator (4 sets of 3 min each, speed will be set at 45 steps∙min-1). Step height will be 20.5 mm. Before and at day 2 post exercise, physiologic measurements will be performed and blood samples will be collected. Then, participants will carry out six weeks of stair descending or ascending training consisting of three exercise sessions per week (the first two weeks the speed will be set at 45 steps∙min-1, the next two weeks at 50 steps∙min-1 and the last two weeks at 55 steps∙min-1 for both groups). Afterward, they will repeat the acute stair descending or ascending protocol, as carried out at the beginning of the study, and the same physiologic measurements will be performed and blood samples will be collected. Measurements: Isometric (at 90 knee flexion), concentric and eccentric peak torque at 60o∙s-1of quadriceps femoris, pain-free range of motion, delayed onset muscle soreness and creatine kinase will be measured.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
NONE
Enrollment
12
Comparison between stair descending and stair ascending training
European University Cyprus
Nicosia, Cyprus
Muscle strength (torque)
An isokinetic dynamometer (Cybex, Ronkonkoma, NY) will be used for the measurement of isometric, eccentric and concentric knee extensor peak torque at 90° knee flexion. The average of the three best maximal voluntary contractions with their dominant leg will be recorded. In order to ensure that the subjects provide their maximal effort, the measurements will be repeated if the difference between the lower and the higher torque value exceeded 10%. There will be two minutes rest between isometric efforts.
Time frame: Change from baseline in muscle strength at day 2 post exercise at the first and sixth week of training
Pain free range of motion (degrees)
The assessment of pain-free ROM will be performed manually using the the isokinetic dynamometer. The investigator will move the calf at a very low angular velocity from 0 knee extension to the position where the subject will feel any discomfort.
Time frame: Before and at day 2 post exercise at the first and sixth week of training
Creatine kinase, CK (activity IU)
CK activity will be measured as a general indicator of muscle damage.It will be measured in a Cobas Integra Plus 400 chemistry analyzer.
Time frame: Before and at day 2 post exercise at the first and sixth week of training
Delayed onset muscle soreness, DOMS (scale 1-10)
Each participant will assess delayed onset muscle soreness (DOMS) during squat movement (90o knee flexion) and perceived soreness will be rated on a scale ranging from 1 (normal) to 10 (very sore).
Time frame: Before and at day 2 post exercise at the first and sixth week of training
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