ElHigh Entrenamiento FuncIntensity Functional de Alta IntensidadTraining (HIFT) es una nuevais a new exercise modalidad de ejercicio que enfatiza los movimientos funcionales multiarticularety that emphasizes multi-joint functional movements adaptables a cualquier nivel de condición física y promueve un mayor reclutamiento muscular to any fitness level and promotes greater muscle recruitment.
1. Introducctióon
AlgunSo
s de los cambios más sme of the most significa
tivos a los que se enfrenta la población mundial son el aumento del número y lant changes facing the world population are the increase in the number and propor
ción de personas mayorestion of older people [
1 ]
yand lathe progres
ión de la esperanza de vida a edades más avanzadas sion of life expectancy to older ages [
2 ].
El deteriCo
ro cognitiv
o es una pose impairment is a possible conse
cuencia delquence of the aging proce
so de envejecimiento, ya que a partir de la tercera década de la vida el cerebro comienza a atrofiarse, disminuyendo su riego sanguíneo y su pesoss, since from the third decade of life the brain begins to atrophy, reducing its blood flow and weight [
3 ].
EThis
to afecta en gran medida el funcionamiento del sistema nervioso central greatly affects the functioning of the central nervous system [
1 ], produci
en
do pérdida de memoria, atencióg loss of memory, attention, reduc
ción de laed learning capaci
dad de aprendizaje y ty and deterior
o de las funcionesation of cognitiv
ae functions [
4 ,
5].
EThis
ta disminución se asocia con un mayor riesgo de demenc decline is associated with an increased risk of dementia, as
í como con resultado well as advers
os para la salud, como limitacionee health outcomes such as func
ionales y discapacidadtional limitations and disability [
6 ].
The burden on health systems caused by dementia and other adverse cognitive outcomes has become a major social challenge with great added financial costs [
7]. New methods are required in order to prevent losses and even improve cognitive performance, functionality, autonomy, and quality of life in general [
6]. For this reason, over the last decades interest has grown concerning the influence of lifestyle factors such as physical exercise on the prevention of cognitive impairment among older people [
6].
Today, physical activity is deemed to be a highly protective factor of cognitive functions in normal brain aging, as well as in several stages of pathology-related cognitive deterioration [
8,
9]. Regular physical exercise has been associated with an increased brain volume of regions related to cognitive functions, which normally decline with age [
10].
ÚltimLa
mente, el entrenamiento de tely, high-intensity interval
os de alta intensidad training (HIIT
, por sus siglas en inglés) ha llamado la atención como una buena opción de ejercicio tanto para la población joven como para la adulta. Este tipo de ejercicio se c) has gained attention as a good exercise option for both the young and adult population. This type of exercise is characteriz
a por sesiones breves e ed by short, intermi
tentes de actividad de altattent sessions of high intensi
dadty activity alterna
das conted with period
os de descanso o de baja s of rest or low intensi
dad. El número de estudios que ty. The number of studies investiga
n este tipo de entrenamiento en la población mayor se hating this type of training in the elderly population has incre
mentado en los últimos añoased in recent years [
2 ,
11 ,
12 ].
UAn
a alternativ
a ale to HIIT
es el entrenamiento funcional de alta intensidadis high-intensity functional training (HIFT
, por sus siglas en inglés), una ), a relatively new training modali
dad de entrenamiento relativamente nueva que enfatiza los movimientos funcionales de múltiples articulaciones que se pueden adaptar a cualquier nivel de condición física y conducen a un mayor reclutamiento muscular que las formas de ejercicio más tradicionales. Las sesiones de HIFT pueden durar desde dosty that emphasizes multi-joint functional movements that can be adapted to any fitness level and lead to greater muscle recruitment than more traditional forms of exercise. HIFT sessions can last anywhere from two minut
os hasta más de una horaes to over an hour [
13 ].
SeIt di
ferencia delffers from HIIT
en el uso de ejercicios funcionales constantemente variados y in the use of constantly varied functional exercises and activi
dades dties of adaptable dura
ción adaptable que pueden o notion that may or may not incorpora
r pausaste breaks. [
14 ]. HIFT empl
eaoys m
úultiple
s vías de energía a través de la utilización de ejercicio energy pathways through the use of multimodal
exercise [
15]. D
ue
bido a los mú to the multiple
s esquemas de prescrip
ción relacionados con las tion schemes related to repeti
ciones y duraciones de los ejercicios etions and exercise durations in HIFT,
los program
as pueden variar desde ejercicios de peso corporal realizados es can range from bodyweight exercises performed in circuit
os o is or timed interval
os cronometrados hasta esquemas más s to more complica
dos queted schemes invol
ucran levantamientos olímpicos, con un número determinado de ving Olympic lifts, with a set number of repeti
cionetions [
13 ].
Although HIIT AND HIFT share many similarities, they differ in that HIIT uses only aerobic exercises performed at very high intensity without variation [
16], whereas HIFT uses constantly varied high-intensity functional and muscle-strengthening exercises of varying durations that may or may not incorporate breaks [
14]. Similarly, studies suggest that HIFT is more effective than HIIT in increasing strength [
17] and adherence to exercise [
15,
18], and strength training increases brain-derived neurotrophic factor [
19] and IGF-1, [
20] myokines important in cognition to a greater extent.
2. High-Intensity Functional Training in Elderly with Cognitive Impairment
Evidence exists of the benefits of HIFT on general cognition in older adults with cognitive impairment, assessed using the MMSE, the ADAS-cog, or both. Two articles that showed improvement in cognitive function used progressive HIFT with 80% RM at 6, 12, and 18 weeks; on the other hand, studies with HIFT interventions at intensities of 12 RM find no significant differences at 3, 4, 6, 7 or at 12 months. However, due to the heterogeneity of intervention protocols, measurement time points, and control group activities, divergent results were evidenced. It is still necessary to determine the modality (load and duration) that guarantees the effectiveness of the intervention.
Khandker et al. [
43], evaluated the comparability of ADAS-cog and MMSE, finding a significant association between MMSE and ADAS-cog (
p < 0.001, R2 = 0.561, in 813 patients and 1520 MMSE/ADAS-cog paired measurements) where increases by 2.01 points (95% CI [1.90, 2.11]) of ADAS-cog were associated with decreases by one point for MMSE.
Furthermore, variability in the HIFT protocols were identified, which was expected because this training modality uses constantly varied, multi-joint exercises of varying duration, with or without rest periods [
14]. Two articles [
34,
37] used intensity-based prescription (%1 RM), while the remaining five articles [
35,
36,
38,
39] used a volume measure (the number of repetitions). Despite these two measures usually being correlated, recent research has raised doubts about the accuracy of this correlation [
45]. It has been reported that the amount of muscle mass used during exercise influences the number of repetitions performed at a given percentage of 1 RM [
46]. Likewise, intensity (expressed as %1 RM) and volume (expressed as the number of repetitions), when used as the only measures of training load control, are insufficient to correctly prescribe this type of training, as it is necessary to control variables such as inter-set recovery duration [
47], the predominance of the eccentric or concentric phase [
48], and speed of execution [
49]. These variations influence force production and other hormonal [
49] and neuromuscular responses [
50]. In addition, there is evidence for a positive association between movement speed and cognition in older adults [
51], and it has been reported that a greater cognitive load is required in eccentric-predominant exercises compared to concentric-predominant ones [
52]. On the other hand, some differences found in the load progression strategies should be pointed out, which could induce different adaptations with respect to load volume [
53]. In the strategy used by Gbiri et al. [
34] the rate of execution of the exercises was monitored, increasing by 10% every 2 weeks. Additionally, the same authors reported an initial measure of the load equal to 80% RM, with no progressions in this regard.
PorOn the ot
ro lado, aunque los her hand, although the benefi
cios del ejercicio sobre la funciónts of exercise on cognitiv
a están biene function are well document
adosed [
54 ,
55 ,
56 ],
una re
visión reciente y un metanálicent review and meta-analysis reve
laron que no hubo un efecto beneficioso de lasaled no beneficial effect of HIIT-only interven
ciones basadas exclusivamente en HIIT sobre el funcionamiento cognitivo de personas contions on cognitive functioning in people with demen
ctia [
57 ].
Por elIn contra
rio, se ha informado que losst, functional exercise-based program
as basados en ejercicio funcional pueden tener ciertos efectos positivos sobre la función cognitiva ens have been reported to have some positive effects on cognitive function in older adult
os mayores con deterioros with mild cognitiv
o leve (DCLe impairment (MCI) [
58].
AIn add
emásition, HIFT ha
sidos been administ
rado aered to older adult
os mayores con demencias with modera
da ate to sever
a en hogares de ancianoe dementia in nursing homes, genera
ndo en esta población alegría y redescubrimiento de competencias corporales, así como unating in this population joy and rediscovery of bodily skills, as well as a safe adherenc
ia segura a las actividades y comprensión de los objetivos de los ejercicioe to activities and understanding of the objectives of the exercises [
59 ].
AsLi
mismo, la akewise, the applicabili
dad de este tipo de ty of this type of interven
ciones se ha tion has been successfully evalua
do con éxito eted in rela
ción con lation to the intensi
dad del ejercicio alcanzadoty of exercise achieved [
60 ].
Sin Howeve
mbargo, losr, the result
ados sobre el efecto des on the effect of HIFT
en laon general cogni
ción general son variados y en algunos casotion are varied and in some cases contradictor
iosy.
EIt is important
e recalcar que aún se necesitan más estudios que realicen un mejor seguimiento de las actividades en el grupo to emphasize that more studies are still needed to better monitor the activities in the control
, así como la e group, as well as the standar
ización de udization of an instrument
o utilizado para evaluar la used to assess general cogni
ción general y un diseño más riguroso de lation and a more rigorous design of the interven
ción. Dicho diseño debetion. This design must consider
ar, por ejemplo, la velocidad de ejecución del ejercicio, el tipo de , for example, the speed of execution of the exercise, the type of contrac
ciótion (conc
éntrica o excéntrica) y el período de recuperación entreentric or eccentric) and the recovery period between series.
Solo así sería poOnly in this way would it be possible
conocer con to know precis
ión los posibles efectoely the possible effects induc
idos por laed by the interven
ción y su duración en el tiempo. Se requiere la ution and their duration over time. Unifica
ción detion of concept
os tanto en las in both interven
ción como en la medición de lastion and measurement variables
en los ECA para diin RCTs is required to elucida
r los efectos delte the effects of HIFT
sobre laon general cogni
ción general en adultos mayores con deteriorotion in older adults with mild to moderate cognitiv
o leve a moderadoe impairment.