High-intensity exercise programs in people with dementia — a systematic review and meta-analysis

Dementia is a syndrome characterized by a progressive deterioration of cognitive and physical functions. The aim of this systematic review was to investigate the effects of high-intensity exercise training (HIT) programs on cognitive and mental health, physical performance, activities of daily living (ADLs) and quality of life (QoL) in people with dementia. A systematic literature search for randomized controlled trials was performed until July 2019. We calculated mean difference (MD) or standardized MD (SMD) and the 95% confidence interval (CI), and assessed heterogeneity using I2 statistic. Nine studies from three large-scale research projects which were based on the high-intensity functional exercise (HIFE) program incorporating strength, balance and mobility exercises of the lower limbs, including 456 participants (85.5 ± 7.0 years), were considered. There was an overall good study quality (mean PEDro score = 7.6 ± 0.7). Compared to seated control activities, strength and balance HIT resulted in statistically significant but small positive effects on balance performance (MD = 2.31, 95% CI = 0.44–4.17, p = 0.02; I2 = 73%) and on the abilities to independently perform ADLs (SMD = 0.28, 95% CI = 0.12–0.44, p = 0.0006; I2 = 0%). No differences were found in cognitive function, depressive symptoms and QoL. The qualitative analyses yielded sporadic beneficial results (mobility, psychological well-being and apathetic behaviour) in favour of HIT. There is only limited evidence for an intensity-related dose–response relationship. Further well-designed studies are needed to identify the best exercise type for different types and stages of dementia.

Acute Cardiopulmonary and Metabolic Responses to High-Intensity Interval Training Protocols Using 60 s of Work and 60 s Recovery

Rozenek, R, Salassi III, JW, Pinto, NM, and Fleming, JD. Acute cardiopulmonary and metabolic responses to high-intensity interval training protocols using 60 s of work and 60 s recovery. J Strength Cond Res 30(11): 3014-3023, 2016-Low-volume, high-intensity interval training (HIIT) consisting of 60 s work and 60 s recovery (60 s/60 s) repeated for 10 times has previously been found to produce beneficial cardiopulmonary, cellular, and metabolic adaptations in healthy and at-risk populations. There is currently relatively little information pertaining to the acute changes that take place during individual training sessions. The purpose of this study was to examine the acute physiological responses to 60 s/60 s × 10 HIIT protocols using several combinations of work and recovery intensities. Eleven healthy adults (mean age ± SD = 26.0 ± 5.3 years) performed 4 HIIT trials on separate days at varying percentages of peak power output that consisted of the following work/recovery intensities: (a) 80% PPO/0% PPO (80/0); (b) 80% PPO/50% PPO (80/50); (c) 100% PPO/0% PPO (100/0); and (d) 100% PPO/50% PPO (100/50). Compared with the other protocols, 100/50 produced higher (p ≤ 0.05) peak, average, and nadir %V[Combining Dot Above]O2peak. Other than the nadir values resulting from the 80/0 trial, all trials produced average, peak, and nadir %V[Combining Dot Above]O2peak and %HRpeak values that were within exercise intensity ranges (≈45-90% V[Combining Dot Above]O2max; ≈65-90% HRmax) recommended by the American College of Sports Medicine for improvement of cardiopulmonary function. Similar average HR and peak HR, RPE, blood lactate, and %V[Combining Dot Above]O2peak values were produced by 80/50 and 100/0 protocols. However, the average %V[Combining Dot Above]O2peak was significantly higher (∼9.3% absolute) in 80/50. It appeared that use of the 80/0, 80/50, and 100/0 protocols would be appropriate for individuals who are at the low to moderate end of the cardiopulmonary fitness spectrum.

High intensity interval training in a real world setting: a randomized controlled feasibility study in overweight inactive adults, measuring change in maximal oxygen uptake

Background

In research clinic settings, overweight adults undertaking HIIT (high intensity interval training) improve their fitness as effectively as those undertaking conventional walking programs but can do so within a shorter time spent exercising. We undertook a randomized controlled feasibility (pilot) study aimed at extending HIIT into a real world setting by recruiting overweight/obese, inactive adults into a group based activity program, held in a community park.

Methods

Participants were allocated into one of three groups. The two interventions, aerobic interval training and maximal volitional interval training, were compared with an active control group undertaking walking based exercise. Supervised group sessions (36 per intervention) were held outdoors. Cardiorespiratory fitness was measured using VO₂max (maximal oxygen uptake, results expressed in ml/min/kg), before and after the 12 week interventions.

Results

On ITT (intention to treat) analyses, baseline (N = 49) and exit (N = 39) O₂ was 25.3±4.5 and 25.3±3.9, respectively. Participant allocation and baseline/exit VO₂max by group was as follows: Aerobic interval training N =  16, 24.2±4.8/25.6±4.8; maximal volitional interval training N = 16, 25.0±2.8/25.2±3.4; walking N = 17, 26.5±5.3/25.2±3.6. The post intervention change in VO₂max was +1.01 in the aerobic interval training, −0.06 in the maximal volitional interval training and −1.03 in the walking subgroups. The aerobic interval training subgroup increased VO₂max compared to walking (p = 0.03). The actual (observed, rather than prescribed) time spent exercising (minutes per week, ITT analysis) was 74 for aerobic interval training, 45 for maximal volitional interval training and 116 for walking (p =  0.001). On descriptive analysis, the walking subgroup had the fewest adverse events.

Conclusions

In contrast to earlier studies, the improvement in cardiorespiratory fitness in a cohort of overweight/obese participants undertaking aerobic interval training in a real world setting was modest. The most likely reason for this finding relates to reduced adherence to the exercise program, when moving beyond the research clinic setting.

Trial Registration

ACTR.org.au ACTRN12610000295044