Purpose
To investigate the training and detraining effects of two different hypoxic high-intensity protocols on cardiorespiratory fitness, maximal fat oxidation and energy contribution in obese ...women.
Methods
82 obese women completed a 12-week training of: (1) interval training in hypoxia (IHT;
n
= 19; 3 min at 90%
W
max
: 3 min at 55–65%
W
max
; FiO
2
= 17.2%), (2) interval training in normoxia (INT;
n
= 20; 3 min at 90%
W
max
: 3 min at 55–65%
W
max
), (3) repeated sprint training in hypoxia (RSH;
n
= 22; 30 s at 130%
W
max
: 3 min at 55–65%
W
max
; FiO
2
= 17.2%), and (4) repeated sprint training in normoxia (RSN;
n
= 21; 30 s at 130%
W
max
: 3 min at 55–65%
W
max
).
V
O
2max
, workload, time to exhaustion and heart rate were assessed at baseline, after completion of 36 training sessions over 12 weeks and after 4 weeks of detraining.
Results
Hypoxic training (IHT and RSH) showed a significant positive effect on absolute (
p
< 0.001) and relative maximal oxygen uptake (
p
< 0.001) as well as VT2 (%
V
O
2max
;
p
< 0.001). Both IHT and RSH showed significantly higher values of absolute
V
O
2max
(IHT: + 26.63%; RSH: + 19.79%) and relative
V
O
2max
(IHT: + 27.95%; RSH: + 19.94%) between baseline and post-exercise (
p
< 0.001).
V
O
2max
(IHT: + 21.74%; RSH: + 17.65%) and relative
V
O
2max
(IHT: + 23.53%; RSH: + 17.15%) remained significantly higher after detraining in IHT and RSH (
p
< 0.001).
Conclusion
A larger improvement in cardiorespiratory fitness has been observed after high-intensity interval training under normobaric hypoxia. As interval training or repeated sprint training did not show a significant effect, RSH might provide a time-metabolic effective strategy in this population.
The increase of wide-spread participation in endurance events in sports such as open water swimming, cycling, running and triathlons, has given rise to a concern about potential implications for ...renal function and kidney health. This study aimed to delve into the findings on exertional rhabdomyolysis (ER) and acute kidney injury (AKI) in endurance sports, emphasizing the diagnostic criteria used, physical and environmental contextual conditions in which ER and AKI are reported. Following PRISMA guidelines for systematic reviews and meta-analysis, topic related studies were searched digital sources (from 2009 to 2020). Studies with biomarkers of ER and AKI reported in endurance or ultra-endurance events were included. A total of 43 publications (sample = 813) were extracted, and 345 (43.5%) individuals were diagnosed with ER (creatinine kinase > 5000 UI/L) and 130 (16.39%) with ER + AKI (creatinine ≥ 1.88 mg/dL). Out of the total cases of ER + AKI, 96.92% were in ultra-endurance runners. There were inconsistences between studies in diagnosis criteria for ER and AKI, which represented a difficulty in the interpretation of the data. Increased levels of muscle and kidney injury immediately after endurance events were reported, but after 5.86 days these levels usually returned to baseline. There is a lack of knowledge around the potential of repeated ER and AKI predisposing to long-term chronic kidney disease. More accurate markers for subclinical and functional AKI diagnosis are needed in the analysis of kidney health after endurance events. ER and AKI are serious clinical problems with significant morbidity. Further research may be in order to help define future prevention strategies.
Among other functions, hypoxia-inducible factor plays a critical role in bone-vascular coupling and bone formation. Studies have suggested that hypoxic conditioning could be a potential ...nonpharmacological strategy for treating skeletal diseases. However, there is no clear consensus regarding the bone metabolism response to hypoxia. Therefore, this review aims to examine the impact of different modes of hypoxia conditioning on bone metabolism. The PubMed and Web of Science databases were searched for experimental studies written in English that investigated the effects of modification of ambient oxygen on bone remodelling parameters of healthy organisms. Thirty-nine studies analysed the effect of sustained or cyclic hypoxia exposure on genetic and protein expression and mineralisation capacity of different cell models; three studies carried out in animal models implemented sustained or cyclic hypoxia; ten studies examined the effect of sustained, intermittent or cyclic hypoxia on bone health and hormonal responses in humans. Different modes of hypoxic conditioning may have different impacts on bone metabolism both in vivo and in vitro. Additional research is necessary to establish the optimal cyclical dose of oxygen concentration and exposure time.
Prevention and treatment of osteoporosis are an issue of great concern in public health so that the increase/maintenance of whole-body bone mineral density (BMD) is clinically relevant and could ...reduce the financial burden. Whole-body vibration (WBV) has been recently proposed as a potential alternative to bone stimulation, which combined with therapies, could provide a new treatment for osteoporosis prevention. In this sense, moderate cyclic hypoxia protocols may help to restrain osteoclastic activity and/or stimulate osteoblastic activity, enhance the effects of whole-body vibration alone. So, the present study investigated the effects of cyclic hypoxic exposure combined with WBV training on BMD of the elderly. Healthy elderly persons (
n
= 30) were randomly assigned to a (1) Hypoxia-Whole Body Vibration group (HWBV;
n
= 10), (2) Normoxic-Whole Body Vibration group (NWBV;
n
= 10) or (3) Control group (CON;
n
= 10). During 18 weeks, HWBV performed WBV treatment under normobaric hypoxic conditions (16.1% FiO
2
). A vibration session included 4 bouts of 30 s (12.6 Hz–4 mm) with 1 min rest between bouts. NWBV performed the same vibration treatment as HWBV but under normoxic conditions. Whole-body and proximal femur BMD (g⋅cm
−2
) were measured using dual-energy X-ray absorptiometry. Two-way ANOVA indicated a borderline significant (
p
= 0.07) time x group interaction for total BMD;
post hoc
analysis revealed a slight but significant (
p
= 0.021) increase of BMD after treatment in the HWBV group. In conclusion, 18-week WBV training with hypoxic stimuli has shown positive effects for the participants of the current study. As changes did not differ significantly between groups, future large-scale studies will be necessary to confirm these findings.
Background
Ageing is accompanied by a loss of muscle mass and function, which are associated with decrease of functional capacity. Combination of WBV training with normobaric hypoxic exposure could ...augment the beneficial effects due to synergic effects of both treatments.
Aims
The purpose of this study was to examine the effects of 36 sessions of the combined WBV training and normobaric hypoxic exposure on muscle mass and functional mobility in older adults.
Methods
Nineteen elderly people were randomly assigned to a: vibration normoxic exposure group (NWBV;
n
= 10; 20.9% FiO
2
) and vibration hypoxic exposure group (HWBV;
n
= 9). Participants developed 36 sessions of WBV training along 18 weeks, which included 4 bouts of 30 s (12.6 Hz in frequency and 4 mm in amplitude) with 60 s of rest between bouts, inside a hypoxic chamber for the HWBV. The “Timed Up and Go Test” evaluated functional mobility. Percentages of lean mass were obtained with dual-energy X-ray absorptiometry.
Results
Neither statistically significant within group variations nor statistically significant differences between both groups were detected to any parameter.
Discussion
Baseline characteristics of population, training protocol and the level of hypoxia employed could cause different adaptations on muscle mass and function.
Conclusions
The combination of WBV training and hypoxic exposure did not cause any effect on either legs lean mass or functional mobility of older adults.
A moderate hypoxic stimulus is considered a promising therapeutic modality for several pathological states including obesity. There is scientific evidence suggesting that when hypoxia and physical ...activity are combined, they could provide benefits for the obese population. The aim of the present study was to investigate if exposure to hypoxia combined with two different protocols of high-intensity interval exercise in overweight/obese women was more effective compared with exercise in normoxia. Study participants included 82 overweight/obese women, who started a 12 week program of 36 sessions, and were randomly divided into four groups: (1) aerobic interval training in hypoxia (AitH; FiO
= 17.2%;
= 13), (2) aerobic interval training in normoxia (AitN;
= 15), (3) sprint interval training in hypoxia (SitH;
= 15), and (4) sprint interval training in normoxia (SitN;
= 18). Body mass, body mass index, percentage of total fat mass, muscle mass, basal metabolic rate, fat, and carbohydrate oxidation, and fat and carbohydrate energy were assessed. Outcomes were measured at baseline (T1), after 18 training sessions (T2), 7 days after the last session (T3), and 4 weeks after the last session (T4). The fat mass in the SitH group was significantly reduced compared with the SitN group from T1 to T3 (
< 0.05) and from T1 to T4 (
< 0.05) and muscle mass increased significantly from T1 to T4 (
< 0.05). Fat mass in the AitH group decreased significantly (
< 0.01) and muscle mass increased (
= 0.022) compared with the AitN group from T1 to T4. All training groups showed a reduction in the percentage of fat mass, with a statistically significant reduction in the hypoxia groups (
< 0.05). Muscle mass increased significantly in the hypoxia groups (
< 0.05), especially at T4. While fat oxidation tended to increase and oxidation of carbohydrates tended to decrease in both hypoxia groups, the tendency was reversed in the normoxia groups. Thus, high-intensity interval training under normobaric intermittent hypoxia for 12 weeks in overweight/obese women seems to be promising for reducing body fat content with a concomitant increase in muscle mass.
CrossFit is high-intensity interval training involving routines called ‘workouts of the day’ (WOD). The aim of the present study is to analyse biochemical parameters and physical performance after ...two modalities of CrossFit WODs, and to evaluate 48-hour recovery. Twelve trained CrossFit practitioners (age: 30.4 ± 5.37 years; VO2max: 47.8 ± 3.63 ml/min/kg; 1RM Power Clean: 93.2 ± 7.62 kg) participated in the study. A crossover design was applied, and participants completed two modalities of WODs on separate days: WOD1 (as many rounds as possible) and WOD2 (rounds for time). Blood lactate, ratings of perceived exertion and heart rate were measured to determine the intensity of training sessions. Biochemical parameters and physical performance were evaluated before, immediately after, 24 hours after and 48 hours after exercise. There were significant differences in intensity between WOD1 and WOD2 (lactate: 13.3±1.87 vs. 18.38±2.02 mmol/L, heart rate mean: 127.6±11.1 vs. 159.8±12.1 bpm), and blood glucose concentrations were significantly higher after WOD2 (135.4 ± 19.6 vs. 167.4±19.6 mg/dL). After exercise, WOD1 and WOD2 caused significant increases of hepatic transaminases, creatine phosphokinase and blood glucose, as well as a large decrease in the physical performance evaluated by the plank test. All these values returned to baseline by 48 hours after exercise. Both WODs caused metabolic and muscular stress, as well as a decrease in physical performance. All the levels recovered at 48 hours, so the stress caused by CrossFit WODs did not induce a pathological state.
Physical inactivity (PI) and sedentary behaviours constitute a global health problem that has negative consequences for health and is also considered the fourth leading risk factor for global ...mortality. A European project named ‘Professional and Personal Experience through Lifelong Learning and Regular Sport’ aims to encourage voluntary participation in sporting activities to achieve its benefits on health. First, a report will be carried out on the effects of physical activity (PA) or inactivity on health, which is often linked to school failure, obesity, self-esteem, etc. The data will be obtained through a completely anonymous online sport and health questionnaire, addressed to all profiles. The data collected through this survey will serve as a basis for understanding the reality of Europeans in terms of quality of life, demographics, physical fitness, and other factors. It is also intended to design a handbook with recommendations for improving health holistically through PA. Finally, the goal is to translate this project into a teaching system for sports professionals, so that they can transfer this knowledge as educational methods to improve people’s health, while adapting it to the particularities of each country, i.e., to provide these sports professionals with tools to train other people.
Purpose The aim of this study was to investigate whether or not a single whole-body vibration treatment after eccentric exercise can reduce muscle soreness and enhance muscle recovery. Subjects and ...Methods Twenty untrained participants were randomly assigned to two groups: a vibration group (n=10) and control group (n=10). Participants performed eccentric quadriceps training of 4 sets of 5 repetitions at 120% 1RM, with 4 min rest between sets. After that, the vibration group received 3 sets of 1 min whole body vibration (12 Hz, 4 mm) with 30 s of passive recovery between sets. Serum creatine kinase, blood urea nitrogen, muscle soreness (visual analog scale) and muscle strength (peak isometric torque) were assessed. Results Creatine kinase was lower in the vibration group than in the control group at 24 h (200.2 ± 8.2 vs. 300.5 ± 26.1 U/L) and at 48 h (175.2 ± 12.5 vs. 285.2 ± 19.7 U/L) post-exercise. Muscle soreness decreased in vibration group compared to control group at 48 h post-exercise (34.1 ± 11.4 vs. 65.2 ± 13.2 mm). Conclusion Single whole-body vibration treatment after eccentric exercise reduced delayed onset muscle soreness but it did not affect muscle strength recovery.
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