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- מאמן בטארגט
מומלץ לראות את הגרפים בתוך המחקר המלא (התוצאות מדהימות) למטה הקישור!
Abstract
The effect of regular aerobic exercise on body fat is negligible; however, other forms of exercise may have a greater impact on body composition. For example, emerging research examining high-intensity intermittent exercise (HIIE) indicates that it may be more effective at reducing subcutaneous and abdominal body fat than other types of exercise. The mechanisms underlying the fat reduction induced by HIIE, however, are undetermined. Regular HIIE has been shown to significantly increase both aerobic and anaerobic fitness. HIIE also significantly lowers insulin resistance and results in a number of skeletal muscle adaptations that result in enhanced skeletal muscle fat oxidation and improved glucose tolerance. This review summarizes the results of HIIE studies on fat loss, fitness, insulin resistance, and skeletal muscle. Possible mechanisms underlying HIIE-induced fat loss and implications for the use of HIIE in the treatment and prevention of obesity are also discussed.
1. Introduction
Most exercise protocols designed to induce fat loss have
focused on regular steady state exercise such as walking and
jogging at a moderate intensity. Disappointingly, these kinds
of protocols have led to negligible weight loss [1, 2]. Thus,
exercise protocols that can be carried out by overweight,
inactive individuals that more effectively reduce body fat
are required. Accumulating evidence suggests that highintensity
intermittent exercise (HIIE) has the potential to be
an economical and effective exercise protocol for reducing fat
of overweight individuals.
HIIE protocols have varied considerably but typically
involve repeated brief sprinting at an all-out intensity
immediately followed by low intensity exercise or rest.
The length of both the sprint and recovery periods has
varied from 6 s to 4min. Most commonly the sprints are
performed on a stationary cycle ergometer at an intensity
in excess of 90% of maximal oxygen uptake (V˙ O2max).
Subjects studied have included adolescents, young men
and women, older individuals, and a number of patient
groups [3–12]. The most utilized protocol in past research
has been the Wingate test which consists of 30 s of allout
sprint with a hard resistance [13]. Subjects typically
perform the Wingate test 4 to 6 times separated by 4 min
of recovery. This protocol amounts to 3 to 4 min of exercise
per session with each session being typically performed 3
times a week for 2 to 6 weeks. Insight into the skeletal muscle
adaptation to HIIE has mainly been achieved using this
type of exercise [13]; however, as this protocol is extremely
hard, subjects have to be highly motivated to tolerate the
accompanying discomfiture. Thus, the Wingate protocol
is likely to be unsuitable for most overweight, sedentary
individuals interested in losing fat. Other less demanding
HIIE protocols have also been utilised. For example, we have
used an 8-second cycle sprint followed by 12 s of low intensity
cycling for a period of 20 min [5]. Thus, instead of 4 to
6 sprints per session, as used in Wingate protocol studies,
subjects using the 8 s/12 s protocol sprint 60 times at a lower
exercise intensity. Total sprint time is 8min with 12 min of
low intensity cycling. For the HIIE Wingate protocols, total
exercise time is typically between 3 to 4min of total exercise
per session. Thus, one of the characteristics of HIIE is that it
involves markedly lower training volume making it a timeefficient
strategy to accrue adaptations and possible health
benefits compared to traditional aerobic exercise programs.
This review summarises results of research examining the
effect of different forms of HIIE on fitness, insulin resistance,
skeletal muscle, subcutaneous, and abdominal fat
loss.
מקור המחקר: http://downloads.hindawi.com/journals/jobe/2011/868305.pdf
Abstract
The effect of regular aerobic exercise on body fat is negligible; however, other forms of exercise may have a greater impact on body composition. For example, emerging research examining high-intensity intermittent exercise (HIIE) indicates that it may be more effective at reducing subcutaneous and abdominal body fat than other types of exercise. The mechanisms underlying the fat reduction induced by HIIE, however, are undetermined. Regular HIIE has been shown to significantly increase both aerobic and anaerobic fitness. HIIE also significantly lowers insulin resistance and results in a number of skeletal muscle adaptations that result in enhanced skeletal muscle fat oxidation and improved glucose tolerance. This review summarizes the results of HIIE studies on fat loss, fitness, insulin resistance, and skeletal muscle. Possible mechanisms underlying HIIE-induced fat loss and implications for the use of HIIE in the treatment and prevention of obesity are also discussed.
1. Introduction
Most exercise protocols designed to induce fat loss have
focused on regular steady state exercise such as walking and
jogging at a moderate intensity. Disappointingly, these kinds
of protocols have led to negligible weight loss [1, 2]. Thus,
exercise protocols that can be carried out by overweight,
inactive individuals that more effectively reduce body fat
are required. Accumulating evidence suggests that highintensity
intermittent exercise (HIIE) has the potential to be
an economical and effective exercise protocol for reducing fat
of overweight individuals.
HIIE protocols have varied considerably but typically
involve repeated brief sprinting at an all-out intensity
immediately followed by low intensity exercise or rest.
The length of both the sprint and recovery periods has
varied from 6 s to 4min. Most commonly the sprints are
performed on a stationary cycle ergometer at an intensity
in excess of 90% of maximal oxygen uptake (V˙ O2max).
Subjects studied have included adolescents, young men
and women, older individuals, and a number of patient
groups [3–12]. The most utilized protocol in past research
has been the Wingate test which consists of 30 s of allout
sprint with a hard resistance [13]. Subjects typically
perform the Wingate test 4 to 6 times separated by 4 min
of recovery. This protocol amounts to 3 to 4 min of exercise
per session with each session being typically performed 3
times a week for 2 to 6 weeks. Insight into the skeletal muscle
adaptation to HIIE has mainly been achieved using this
type of exercise [13]; however, as this protocol is extremely
hard, subjects have to be highly motivated to tolerate the
accompanying discomfiture. Thus, the Wingate protocol
is likely to be unsuitable for most overweight, sedentary
individuals interested in losing fat. Other less demanding
HIIE protocols have also been utilised. For example, we have
used an 8-second cycle sprint followed by 12 s of low intensity
cycling for a period of 20 min [5]. Thus, instead of 4 to
6 sprints per session, as used in Wingate protocol studies,
subjects using the 8 s/12 s protocol sprint 60 times at a lower
exercise intensity. Total sprint time is 8min with 12 min of
low intensity cycling. For the HIIE Wingate protocols, total
exercise time is typically between 3 to 4min of total exercise
per session. Thus, one of the characteristics of HIIE is that it
involves markedly lower training volume making it a timeefficient
strategy to accrue adaptations and possible health
benefits compared to traditional aerobic exercise programs.
This review summarises results of research examining the
effect of different forms of HIIE on fitness, insulin resistance,
skeletal muscle, subcutaneous, and abdominal fat
loss.
מקור המחקר: http://downloads.hindawi.com/journals/jobe/2011/868305.pdf
