CHANGES IN AEROBIC FITNESS PARAMETERS ASSOCIATED WITH DIET AND EXERCISE PROGRAMS IN OVERWEIGHT ADULTS

An accurate estimation of critical speed (CS) is important to accurately define the boundary between heavy and severe intensity domains when prescribing exercise. Hence, our aim was to compare CS estimates obtained by statistically appropriate fitting procedures, i.e., regression analyses that correctly consider the dependent variables of the underlying models. A second aim was to determine the correlations between estimated CS and aerobic fitness parameters, i.e., ventilatory threshold, respiratory compensation point, and maximal rate of oxygen uptake. Sixteen male runners performed a maximal incremental aerobic test and four exhaustive runs at 90, 100, 110, and 120% of the peak speed of the incremental test on a treadmill. Then, two mathematically equivalent formulations (time as function of running speed and distance as function of running speed) of three different mathematical models (two-parameter, three-parameter, and three-parameter exponential) were employed to estimate CS, the distance that can be run above CS (d′), and if applicable, the maximal instantaneous running speed (smax). A significant effect of the mathematical model was observed when estimating CS, d′, and smax (P < 0.001), but there was no effect of the fitting procedure (P > 0.77). The three-parameter model had the best fit quality (smallest Akaike information criterion) of the CS estimates but the highest 90% confidence intervals and combined standard error of estimates (%SEE). The 90% CI and %SEE were similar when comparing the two fitting procedures for a given model. High and very high correlations were obtained between CS and aerobic fitness parameters for the three different models (r ≥ 0.77) as well as reasonably small SEE (SEE ≤ 6.8%). However, our results showed no further support for selecting the best mathematical model to estimate critical speed. Nonetheless, we suggest coaches choosing a mathematical model beforehand to define intensity domains and maintaining it over the running seasons.

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Effect of 9 weeks continuous vs. interval aerobic training on plasma BDNF levels, aerobic fitness, cognitive capacity and quality of life among seniors with mild to moderate Alzheimer’s disease: a randomized controlled trial

European Review of Aging and Physical Activity ◽

10.1186/s11556-019-0234-1 ◽

2020 ◽

Vol 17 (1) ◽

Author(s):

Lievyn Enette ◽

Thomas Vogel ◽

Sylvie Merle ◽

Anna-Gaelle Valard-Guiguet ◽

Nathalie Ozier-Lafontaine ◽

...

Keyword(s):

Quality Of Life ◽

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Performance ◽

Aerobic Fitness ◽

Aerobic Training ◽

Bdnf Level ◽

Fitness Parameters ◽

Functional Capacities

Abstract Background Evidence suggests that aerobic-type training confers physical benefits and appears to contribute positively to brain health. This study aims to compare the effect of 9-weeks continuous (CAT) to interval aerobic training (IAT) on brain derived neurotrophic factor (BDNF) plasma level, aerobic fitness, cognitive performance, and quality of life among senior with Alzheimer’s disease (AD). Methods 52 participants were randomly allocated into three groups (CAT n = 14; IAT n = 17; and Controls n = 21). CAT and IAT consisted of 18 sessions of 30-min cycling, twice a week, over 9 weeks. During the same period, controls were engaged in interactive information sessions. Plasma BDNF level; aerobic fitness parameters (Metabolic equivalent task - METs; Maximal Tolerated Power – MTP); functional capacities (6-Minute Walk Test - 6MWT); cognitive performance (Mini Mental State Examination; Rey auditory verbal learning test; and digit span test) and quality of life (Quality Of Life of Alzheimer’s Disease scale - QoL-AD) were measured in all participants at baseline and 9 weeks later. A third plasma BDNF level was quantified following a 4 weeks detraining. Results No significant change was measured in terms of plasma BDNF level and cognitive performance after interventions, in all groups compared to baseline. After 9 weeks, CAT and IAT significantly improved aerobic fitness parameters compared to controls (METs: + 0.6 and + 1.0 vs. + 0.4; MTP: + 16 watts and + 20 watts vs. + 10 watts; and functional capacities (6MWT: + 22 m and + 31 m vs. -40 m). Compared to controls, QoL-AD after CAT was improved (+ 2 points; p = 0.02). Conclusions Neither aerobic exercise modalities significantly modified plasma BDNF levels and cognitive performances. CAT and IAT enhanced aerobic fitness and functional capacities in AD patients and CAT their QoL. Trial registration ClinicalTrials.gov website (NCT02968875); registration date: 7 September 2016. “Retrospectively registered”.

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Maximal and submaximal aerobic fitness in postmenopausal women: influence of hormone-replacement therapy

Applied Physiology Nutrition and Metabolism ◽

10.1139/h08-070 ◽

2008 ◽

Vol 33 (5) ◽

pp. 922-928 ◽

Cited By ~ 3

Author(s):

Liza Stathokostas ◽

John M. Kowalchuk ◽

Robert J. Petrella ◽

Donald H. Paterson

Keyword(s):

Oxygen Consumption ◽

Hormone Replacement Therapy ◽

Replacement Therapy ◽

Postmenopausal Women ◽

Body Mass ◽

Aerobic Fitness ◽

Ventilatory Threshold ◽

Hormone Replacement ◽

Peak Oxygen Consumption ◽

Fitness Parameters

The purpose of this study was to examine whether maximal and submaximal aerobic fitness parameters (peak oxygen consumption and ventilatory threshold, respectively) are affected by hormone-replacement therapy (HRT) in moderately active postmenopausal women. Forty healthy, active, postmenopausal women (21 taking HRT, mean age 62 ± 5 years; 19 not taking HRT, mean age 62 ± 7 years) met the peak oxygen consumption criteria during a cycle ergometer test (15 W ramp) and achieved volitional fatigue. Breath-by-breath measurement was used to determine peak oxygen consumption and to estimate ventilatory threshold. There were no differences in characteristics (age, body mass, height, body mass index, leisure-time physical activity) between the non-HRT and HRT groups, nor were there any differences in responses to maximal exercise, with an observed peak oxygen consumption (mL·kg–1·min–1) of 22.9 ± 3.8 in the non-HRT group and 22.0 ± 4.7 in the HRT group. There was also no difference in submaximal aerobic capacity, with ventilatory threshold values (mL·kg–1·min–1) of 16.7 ± 3.4 in the non-HRT group and 15.6 ± 3.2 in the HRT group. In a sample of healthy moderately active postmenopausal women, there was no difference in maximal or submaximal aerobic fitness parameters beteen the HRT and non-HRT groups.

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