Resistance training induced increase in VO2max in young and older subjects

Combined exercise training decreases blood pressure in OLDER women with NOS3 polymorphism providing changes in differentially methylated regions (DMRs)

The mechanisms by which the ageing process is associated to an unhealthy lifestyle and how they play an essential role in the aetiology of systemic arterial hypertension have not yet been completely elucidated. Our objective is to investigate the influence of NOS3 polymorphisms [-786T > C and (Glu298Asp)] on systolic blood pressure (SBP) and diastolic blood pressure (DBP) response, differentially methylated regions (DMRs), and physical fitness of adult and older women after a 14-week combined training intervention. The combined training was carried out for 14 weeks, performed 3 times a week, totalling 180 minutes weekly. The genotyping experiment used Illumina Infinium Global Screening Array version 2.0 (GSA V2.0) and Illumina's EPIC Infinium Methylation BeadChip. The participants were separated into SNP rs2070744 in TT (59.7 ± 6.2 years) and TC + CC (60.0 ± 5.2 years), and SNP rs17999 in GluGlu (58.8 ± 5.7 years) and GluAsp + AspAsp (61.6 ± 4.9 years). We observed an effect of time for variables BP, physical capacities, and cholesterol. DMRs related to SBP and DBP were identified for the rs2070744 and rs17999 groups pre- and decreased numbers of DMRs post-training. When we analysed the effect of exercise training in pre- and post-comparisons, the GluGlu SNP (rs17999) showed 10 DMRs, and after enrichment, we identified several biological biases. The combined training improved the SBP and DBP values of the participants regardless of the SNPs. In addition, exercise training affected DNA methylation differently between the groups of NOS3 polymorphisms.

Molecular aspects of the exercise response and training adaptation in skeletal muscle

Skeletal muscle plasticity enables an enormous potential to adapt to various internal and external stimuli and perturbations. Most notably, changes in contractile activity evoke a massive remodeling of biochemical, metabolic and force-generating properties. In recent years, a large number of signals, sensors, regulators and effectors have been implicated in these adaptive processes. Nevertheless, our understanding of the molecular underpinnings of training adaptation remains rudimentary. Specifically, the mechanisms that underlie signal integration, output coordination, functional redundancy and other complex traits of muscle adaptation are unknown. In fact, it is even unclear how stimulus-dependent specification is brought about in endurance or resistance exercise. In this review, we will provide an overview on the events that describe the acute perturbations in single endurance and resistance exercise bouts. Furthermore, we will provide insights into the molecular principles of long-term training adaptation. Finally, current gaps in knowledge will be identified, and strategies for a multi-omic and -cellular analyses of the molecular mechanisms of skeletal muscle plasticity that are engaged in individual, acute exercise bouts and chronic training adaptation discussed.

Cardiorespiratory and aerobic demands of squat exercise

Squatting, a traditional resistance exercise classified as strength training, relies on anaerobic pathways, but its aerobic aspects remain unclear. We examined heart rate and oxygen demand during squats, exploring variations across different strength statuses. It fills gaps in understanding the cardiorespiratory effects of squatting, especially during multiple sets. Twenty-two young healthy resistance trained men (age: 28 ± 4 years) participated. Maximal oxygen consumption (V̇O2max) and 1 repetition maximum (RM) of squat were measured. Participants performed 5 sets of squat exercises at 65% of 1RM for 10 repetitions with 3-min rest intervals. Heart rate and pulmonary gas exchange were measured during the squat exercise. Participants were divided into high strength (HS; upper 50%) and low strength (LS; lower 50%) groups based on a median split of their 1 RM squat values (normalized to their body weight). During 5 sets of squat exercise, oxygen consumption (V̇O2) increased up to 47.8 ± 8.9 ml/kg/min, corresponding to 100.6% of predetermined V̇O2max. The HS group achieved a greater highest point of V̇O2 in relation to V̇O2max than the LS group (108.0 vs. 93.7%). During the exercise intervals, V̇O2 exceeded V̇CO2, while during the rest intervals, V̇CO2 surpassed V̇O2. Our findings suggest that the oxygen demand during squatting is notably substantial, which may vary according to the training status.

Greater physical fitness ( VO 2 max ) in healthy older adults associated with increased integrity of the locus coeruleus-noradrenergic system

AIM

Physical activity (PA) is a key component for brain health and Reserve, and it is among the main dementia protective factors. However, the neurobiological mechanisms underpinning Reserve are not fully understood. In this regard, a noradrenergic (NA) theory of cognitive reserve (Robertson, 2013) has proposed that the upregulation of NA system might be a key factor for building reserve and resilience to neurodegeneration because of the neuroprotective role of NA across the brain. PA elicits an enhanced catecholamine response, in particular for NA. By increasing physical commitment, a greater amount of NA is synthetised in response to higher oxygen demand. More physically trained individuals show greater capabilities to carry oxygen resulting in greaterVo 2 max - a measure of oxygen uptake and physical fitness (PF).

METHODS

We hypothesized that greaterVo 2 max would be related to greater Locus Coeruleus (LC) MRI signal intensity. In a sample of 41 healthy subjects, we performed Voxel-Based Morphometry analyses, then repeated for the other neuromodulators as a control procedure (Serotonin, Dopamine and Acetylcholine).

RESULTS

As hypothesized, greaterVo 2 max related to greater LC signal intensity, and weaker associations emerged for the other neuromodulators.

CONCLUSION

This newly established link betweenVo 2 max and LC-NA system offers further understanding of the neurobiology underpinning Reserve in relationship to PA. While this study supports Robertson's theory proposing the upregulation of the NA system as a possible key factor building Reserve, it also provides ground for increasing LC-NA system resilience to neurodegeneration viaVo 2 max enhancement.

Cardiorespiratory dynamics of type 2 diabetes mellitus: An extensive view of breathing and fitness challenges in a diabetes prevalent population

BACKGROUND

Diabetes mellitus (DM) is well known for related micro and macrovascular complications. Uncontrolled hyperglycemia in diabetes mellitus leads to endothelial dysfunction, inflammation, microvascular impairment, myocardial dysfunction, and skeletal muscle changes which affect multiple organ systems. This study was designed to take an extensive view of cardiorespiratory dynamics in patients with type 2 DM.

METHODS

One hundred healthy controls (HC) and 100 DM patients were enrolled. We measured and compared the breathing patterns (spirometry), VO2 max levels (heart rate ratio method) and self-reported fitness level (international fitness scale) of individuals with and without diabetes. Data was analyzed in SPSS v.22 and GraphPad Prism v8.0.

RESULTS

We observed restrictive spirometry patterns (FVC <80%) in 22% of DM as compared to 2% in HC (p = 0.021). There was low mean VO2 max in DM as compared to HC(32.03 ± 5.36 vs 41.91 ± 7.98 ml/kg/min; p value <0.001). When evaluating physical fitness on self-reported IFiS scale, 90% of the HC report average, good, or very good fitness levels. In contrast, only 45% of the DM shared this pattern, with a 53% proportion perceiving their fitness as poor or very poor (p = <0.05). Restrictive respiratory pattern, low VO2 max and fitness level were significantly associated with HbA1c and long-standing DM.

CONCLUSION

This study shows decreased pulmonary functions, decreased cardiorespiratory fitness (VO2 max) and IFiS scale variables in diabetic population as compared to healthy controls which are also associated with glycemic levels and long-standing DM. Screening for pulmonary functions can aid optimum management in this population.

Becoming a World Champion Powerlifter at 71 Years of Age: It Is Never Too Late to Start Exercising

This case study assessed body composition, muscle strength, cardiorespiratory fitness, and metabolic health of the present female world champion powerlifter in the 70+ age category who started resistance exercise training at 63 years of age with no prior experience with structured exercise training. Measures of body composition (magnetic resonance imaging, computed tomography, and dual-energy X-ray absorptiometry scanning, leg volume); strength (one-repetition maximum leg press and extension, maximum voluntary contraction, and handgrip strength); physical function (short physical performance battery); cardiorespiratory fitness (peak oxygen consumption); and metabolic health (oral glucose tolerance test) were assessed. In addition, a muscle biopsy was collected to assess muscle fiber type distribution and cross-sectional area (CSA). Where possible, data were compared with previously (un)published sex- and age-matched data using z scores. Skeletal muscle mass index was calculated by dividing limb muscle mass by height squared. Data from the control groups are expressed as mean ± 95% confidence interval. Our participant (age: 71 years; body mass: 64.5 kg; body mass index: 27.6 kg/m2) reported a good bone mineral density of 1.09 g/cm2 (T score between -1 and +1) and very low values of abdominal and organ body fat (i.e., between 20% and 70% lower compared with a reference group of postmenopausal women). In addition, she showed a 33% greater skeletal muscle mass index when compared with healthy, older female control subjects (7.9 vs. 5.9 [5.7-6.2] kg/m2; n = 61) as well as 37% greater muscle quadriceps CSA (63.8 vs. 46.6 [44.5-48.7] cm2; n = 48) and 46% greater Type II muscle fiber CSA (4,536 vs. 3,097 [2,707-3,488] μm2; n = 19). Absolute leg press muscle strength was 36% greater (190 vs. 140 [132-147] kg; n = 30) and handgrip strength was 33% greater (33 vs. 25 [23-26] kg; n = 48) when compared with healthy, age-matched controls. In conclusion, even for resistance exercise naïve individuals, starting exercise at an advanced age can lead to improvements in body composition and muscle strength allowing older adults to reduce the risk for developing metabolic syndrome, live independently, and even compete at a world class level.

The effects of kettlebell training versus resistance training using the own body mass on physical fitness and physiological adaptations in obese adults: a randomized controlled trial

AIM OF STUDY

This study aimed to explore the effects of different types of resistance training using kettlebells versus the own body mass, in comparison to a passive control, on key physical fitness and physiological parameters in young, obese adults.

METHODS

Data from 60 sedentary, obese male college students, aged 17-26, were used for final analyses. Participants were randomly assigned to one of three groups: a control group (CG, n = 20, no training), a kettlebell resistance training group (KRTG, n = 20), or a bodyweight resistance training group (BWRTG, n = 20). Selected measures of physical fitness were tested using the 12-minutes run test, the push-up test, the sit-up test, and the sit-and-reach test. Physiological measures included vital capacity, resting and maximum heart rate (HRmax), mean arterial blood pressure, breath holding time, and respiratory rate. Biochemical variables were measured in the morning, in a fasted state, and comprised high and low density lipoprotein, total cholesterol, and triglycerides. The 12-weeks progressive KRTG and BWRTG were specifically tailored using sets, repetitions, and intensity levels.

RESULTS

Notable findings include significant body fat reductions in BWRTG (p < 0.001; d = 1.53) and KRTG (p < 0.001; d = 1.43), and a substantial increase in VO2max for BWRTG (p < 0.001; d = 1.32) and KRTG (p < 0.001; d = 1.34) compared to CG. KRTG also showed significant improvements in vital capacity (p < 0.001; d = 1.61) and reductions in resting heart rate (p = 0.024, d = 1.05) and respiratory rate (p = 0.001, d = 1.55), with BWRTG showing similar trends (resting heart rate: p = 0.041, d = 1.35; respiratory rate: p = 0.001, d = 1.98). Both intervention groups significantly improved breath holding time (KRTG: p = 0.001, d = 1.58; BWRTG: p < 0.001, d = 1.98) and reduced total cholesterol and low-density lipoprotein levels compared to CG.

CONCLUSIONS

This study demonstrates that both KRTG and BWRTG are effective in improving body composition and selected fitness and physiological measures. Thus, resistance training using kettlebells or bodyweight training are recommended if the goal is to improve body composition and fitness in obese male adults.

TRIAL REGISTRATION

OSF, September, 28th 2023. https://doi.org/10.17605/OSF.IO/Z6Y9Gosf.io/2mb98.

Exercise induces tissue-specific adaptations to enhance cardiometabolic health

The risk associated with multiple cancers, cardiovascular disease, diabetes, and all-cause mortality is decreased in individuals who meet the current recommendations for physical activity. Therefore, regular exercise remains a cornerstone in the prevention and treatment of non-communicable diseases. An acute bout of exercise results in the coordinated interaction between multiple tissues to meet the increased energy demand of exercise. Over time, the associated metabolic stress of each individual exercise bout provides the basis for long-term adaptations across tissues, including the cardiovascular system, skeletal muscle, adipose tissue, liver, pancreas, gut, and brain. Therefore, regular exercise is associated with a plethora of benefits throughout the whole body, including improved cardiorespiratory fitness, physical function, and glycemic control. Overall, we summarize the exercise-induced adaptations that occur within multiple tissues and how they converge to ultimately improve cardiometabolic health.

Self-selected or fixed: is there an optimal rest interval for controlling intensity in high-intensity interval resistance training?

PURPOSE

This study investigated the effects of different rest interval strategies during high-intensity interval resistance training (HIRT) on cardiorespiratory, perceptual, and enjoyment responses among trained young men.

METHODS

Sixteen men experienced with HIRT underwent cardiopulmonary exercise testing and were familiarized with the exercises and HIRT protocol. On the subsequent three visits, interspaced 48-72 h, participants performed HIRT sessions with different rest intervals in a randomized order: 10 s and 30 s fixed rest intervals (FRI-10 and FRI-30), and self-selected rest interval (SSRI). Oxygen uptake (VO2), heart rate (HR), and recovery perception (Total Quality Recovery Scale) were measured during HIRT, while enjoyment responses (Physical Activity Enjoyment Scale) were assessed immediately after the sessions.

RESULTS

The VO2 during exercise was greater in FRI-10 than FRI-30 (55% VO2max and 47% VO2max, respectively, p = 0.01), while no difference occurred between SSRI and bouts performed with fixed intervals (52% VO2max vs. FRI, p > 0.05). HR, excess post-exercise oxygen consumption (EPOC), recovery perception, and enjoyment responses were similar across conditions (p > 0.05).

CONCLUSION

Exercise intensity was not affected by the rest interval strategy. High exercise intensity was maintained in sessions performed with FRI or SSRI, without negative repercussions on the duration of training sessions and enjoyment responses after exercise sessions.

Greater physical fitness (Vo2Max) in healthy older adults associated with increased integrity of the Locus Coeruleus-Noradrenergic system

Physical activity (PA) is a key component for brain health and Reserve, and it is among the main dementia protective factors. However, the neurobiological mechanisms underpinning Reserve are not fully understood. In this regard, a noradrenergic (NA) theory of cognitive reserve (Robertson, 2013) has proposed that the upregulation of NA system might be a key factor for building reserve and resilience to neurodegeneration because of the neuroprotective role of NA across the brain. PA elicits an enhanced catecholamine response, in particular for NA. By increasing physical commitment, a greater amount of NA is synthetised in response to higher oxygen demand. More physically trained individuals show greater capabilities to carry oxygen resulting in greater Vo2max - a measure of oxygen uptake and physical fitness (PF). In the current study, we hypothesised that greater Vo2 max would be related to greater Locus Coeruleus (LC) MRI signal intensity. As hypothesised, greater Vo2max related to greater LC signal intensity across 41 healthy adults (age range 60-72). As a control procedure, in which these analyses were repeated for the other neuromodulators' seeds (for Serotonin, Dopamine and Acetylcholine), weaker associations emerged. This newly established link between Vo2max and LC-NA system offers further understanding of the neurobiology underpinning Reserve in relationship to PA. While this study supports Robertson's theory proposing the upregulation of the noradrenergic system as a possible key factor building Reserve, it also provide grounds for increasing LC-NA system resilience to neurodegeneration via Vo2max enhancement.

Exercise metabolism and adaptation in skeletal muscle

Viewing metabolism through the lens of exercise biology has proven an accessible and practical strategy to gain new insights into local and systemic metabolic regulation. Recent methodological developments have advanced understanding of the central role of skeletal muscle in many exercise-associated health benefits and have uncovered the molecular underpinnings driving adaptive responses to training regimens. In this Review, we provide a contemporary view of the metabolic flexibility and functional plasticity of skeletal muscle in response to exercise. First, we provide background on the macrostructure and ultrastructure of skeletal muscle fibres, highlighting the current understanding of sarcomeric networks and mitochondrial subpopulations. Next, we discuss acute exercise skeletal muscle metabolism and the signalling, transcriptional and epigenetic regulation of adaptations to exercise training. We address knowledge gaps throughout and propose future directions for the field. This Review contextualizes recent research of skeletal muscle exercise metabolism, framing further advances and translation into practice.

Cardiopulmonary Exercise Testing, Rehabilitation, and Exercise Training in Postpulmonary Embolism

Long-term exercise intolerance and functional limitations are common after an episode of acute pulmonary embolism (PE), despite 3 to 6 months of anticoagulation. These persistent symptoms are reported in more than half of the patients with acute PE and are referred as "post-PE syndrome." Although these functional limitations can occur from persistent pulmonary vascular occlusion or pulmonary vascular remodeling, significant deconditioning can be a major contributing factor. Herein, the authors review the role of exercise testing to elucidate the mechanisms of exercise limitations to guide next steps in management and exercise training for musculoskeletal deconditioning.

Right Ventricular Morphology and Function after Exercise Training in People with Systemic Sclerosis: A Randomized Controlled Pilot Study

BACKGROUND

Vascular dysfunction and its concomitant multi-organ involvement, including cardiac involvement, affects prognosis in systemic sclerosis (SSc) patients. Regular exercise has demonstrated to be able to improve vascular function in SSc. However, the effects of an exercise program on the heart and specifically in right ventricular (RV) morphology and function in SSc have yet to be explored. The study aimed to examine whether a 3-month combined exercise program can affect RV morphology and function in SSc patients.

METHODS

Twenty-eight SSc patients were randomly allocated to either the exercise training (ET) or the control (CON) group. Baseline and follow-up assessments consisted of a cardiopulmonary exercise test along with both a conventional and a two-dimensional speckle tracking echocardiography (2DSTE) focused on RV morphology and function. Following the baseline assessments, Group ET participated in a supervised combined exercise program for 12 weeks, while group CON received their usual care.

RESULTS

The ET group demonstrated increases in peak oxygen consumption by 25.1% (p < 0.001), global RV free wall longitudinal systolic strain by 6.69% (p < 0.03), RV free wall longitudinal systolic strain of the basal segment by 13.5% (p < 0.001), and global RV four-chamber longitudinal systolic strain by 6.76% (p < 0.03) following the exercise program. No differences were observed in group CON.

CONCLUSIONS

Combined exercise improved cardiorespiratory efficiency and indices of RV systolic function, as assessed by the 2DSTE, in SSc patients.

The Efficacy of an Immersive Virtual Reality Exergame Incorporating an Adaptive Cable Resistance System on Fitness and Cardiometabolic Measures: A 12-Week Randomized Controlled Trial

Exergaming, combining elements of video game into the realm of exercise, has recently incorporated immersive virtual reality (IVR) with resistance training. Thirty-two participants (14 females, mean age = 24.3) were randomized to IVR or self-directed control group (SELF) and worked out thrice weekly for 12 weeks (for 36 sessions). The IVR group spent 14 fewer minutes per session (p < 0.001) while reporting the sessions “enjoyable’. Compared to SELF, the IVR group had significantly greater improvement in changes from baseline to post-training in upper-and-lower muscular strength (1-RM) and muscular endurance (85% 1-RM) (14.3 kg vs. 10.0 kg for 1-RM upper, 28.6 kg vs. 22.5 kg for 1-RM lower, 2.6 reps vs. 1.9 reps for 85% 1-RM of upper, 2.7 vs. 2.0 reps for 85% 1-RM of lower, all p < 0.001), peak leg power (1424 vs. 865 W, p < 0.001), body fat% (−3.7% vs. −1.9%, p < 0.001), heart rate variability (4.3 vs. 1.8 ms, p < 0.001), rVO2max (3.28 vs. 0.89 mL/min/kg, p < 0.001) with decreased systolic BP (−0.4 vs. −2.3 mmHg, p < 0.001), and level of perceived exertion during workouts (RPE 14 vs. 16, p < 0.001). With its high-paced and action-filled gaming coupled with superior fitness and cardiometabolic outcomes, this IVR exergaming platform should be considered as another exercise modality for performance and health-related training.

German volume training for health promotion: Acute vasopressor, pulmonary and metabolic responses

Resistance training (RT) is increasingly recommended for incorporation into comprehensive fitness or "exercise as medicine" programs. However, the acute effects of RT, and especially its different sub-types, and how they impact health outcomes are not fully investigated. This study evaluated German Volume Training (GVT) ("10 set × 10 rep scheme") for its efficacy for its use in health settings. This study utilized a randomized crossover design with subjects serving as their own controls to establish baseline values. Subjects were blinded to the study hypothesis. Subjects performed a single session of GVT or no exercise, in a randomised order separated by a 1-week washout period. Outcomes were assessed before and immediately post-exercise. GVT significantly (p < 0.05) decreased systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP), but increased heart rate (HR), rate pressure product (RPP) and rating of perceived exertion (RPE). No changes were found in the measured spirometry parameters. Increases were observed in carbon dioxide production (VCO₂) and minute ventilation (V_E), but not respiratory exchange ratio. Post hoc analysis demonstrated that post-GVT values were significantly lower for SBP (p = 0.017; d = 1.00), DBP (p = 0.013; d = 0.90), MAP (p = 0.024; d = 1.06), and VCO₂ (p = 0.009; d = -1.32), and significantly higher for RPP (p = 0.001; d = -3.11), RPE (p = 0.001; d = -14.14), and HR (p = 0.001; d = -3.00). This study indicates that acute GVT promotes post-exercise hypotension and is of sufficient intensity to increase both objective HR and subjective RPE intensities appropriately for use in a variety of health promotion settings.

Vitamin D Supplementation Has No Impact on Cardiorespiratory Fitness, but Improves Inflammatory Status in Vitamin D Deficient Young Men Engaged in Resistance Training

Data on the effect of vitamin D (Vit-D) supplementation on cardiorespiratory fitness (VO2max) are conflicting. A possible source of discrepancies in the literature is the heterogeneity in baseline Vit-D status among participants in previous studies. The main objectives of the present study were to assess the impact of Vit-D supplementation on VO2max and inflammatory status in Vit-D deficient young healthy men. Participants (n = 39, baseline serum Vit-D level < 50 nmol/L) were quasi-randomly assigned to one of the two groups, which, in a double-blind manner, supplemented their diet daily with either Vit-D (8000 IU; VD) or placebo (PLC) and concomitantly performed a 12-week supervised resistance training program. During the 12-week intervention, serum Vit-D concentrations increased 3.9-fold (p < 0.001) in the VD group while no changes occurred in the PLC group. Baseline VO2max did not differ in the two groups and remained unchanged during the intervention. Serum interleukin-10/tumour necrosis factor alpha ratio increased significantly (30%, p = 0.007; effect size 0.399) in VD but not in PLC group. In conclusion, 12-week Vit-D supplementation increases serum 25(OH)D levels and improves inflammatory status, but has no impact on VO2max in Vit-D deficient young men engaged in resistance training.

[Efficacy of the different therapeutic exercise modalities in cardiac rehabilitation after myocardial infarction. A review of the literature]

We aimed to assess the efficacy of different therapeutic exercise modalities in cardiac rehabilitation after acute myocardial infarction. A search of randomized controlled studies published between 2016 and 2021 in Scopus, PubMed, CINAHL, Web of Science and Cochrane Library was carried out using the MeSH terms "exercise therapy" and "myocardial infarction". Ten articles met the inclusion criteria; in these studies, the used exercises were combined or traditional programs that included relaxation training, and were performed either at home or at the hospital. We examined exercise tolerance, cardiovascular parameters, anthropometric measurements, and quality of life. Significant improvements in the assessed variables were observed in most studies. We conclude that all studied therapeutic exercise modalities are useful in cardiac rehabilitation after myocardial infarction, although the best outcomes are seen for combined therapeutic exercise programs.

An evaluation of cardiopulmonary endurance and muscular strength in adults living with sickle cell disease

There have been limited investigations into exercise in sickle cell disease (SCD). In the general population, health is reflected in general physical fitness. It is unclear if the same associations are seen in people with SCD. Here, we report a cross-sectional assessment of two important measures of physical fitness, muscle strength and cardiorespiratory endurance, in adults with SCD. A total of 29 adults with SCD (aged 24-62 years; 72% female) completed cardiopulmonary and muscular strength testing using a cycle ergometer and an isokinetic dynamometer. Adults with SCD had lower median values for cardiorespiratory endurance (the median [interquartile range, IQR] peak oxygen uptake [VO₂ ] 16.1 [6.3] vs. 42.65 [11.3] ml/kg/min, p < 0.001) and knee strength (median [IQR] flexor torque 26.91[22.5] vs. 55.6 [22.7] Nm, p < 0.001) compared to controls and predicted values. Interestingly, there was a very positive association between muscular strength and peak VO₂ values for adults with SCD (r = 0.53, p = 0.003) suggesting these values may be useful in determining cardiopulmonary health.

Effects of Running-Specific Strength Training, Endurance Training, and Concurrent Training on Recreational Endurance Athletes' Performance and Selected Anthropometric Parameters

OBJECTIVE

The present study aimed to verify the effects of running-specific strength training alone, endurance training alone, and concurrent training on recreational endurance athletes' performance and selected anthropometric parameters.

METHOD

Thirty male recreational endurance runners were randomly assigned using a blocking technique to either a running-specific strength training group (RSSTG), an endurance training group (ETG), or a concurrent training group (CTG). RSSTG performed three strength-training sessions per week orientated to running, ETG underwent three endurance sessions per week, and CTG underwent a 3-day-per-week concurrent training program performed on non-consecutive days, alternating the strength and endurance training sessions applied to RSSTG and ETG. The training protocol lasted 12 weeks and was designed using the ATR (Accumulation, Transmutation, Realization) block periodization system. The following assessments were conducted before and after the training protocol: body mass (BM), body mass index (BMI), body fat percentage (BFP), lean mass (LM), countermovement jump (CMJ), 1RM (one-repetition maximum) squat, running economy at 12 and 14 km/h (RE12 and RE14), maximum oxygen consumption (VO₂max), and anaerobic threshold (AnT).

RESULTS

RSSTG significantly improved the results in CMJ, 1RM squat, RE12, and RE14. ETG significantly improved in RE12, RE14, VO₂max, and AnT. Finally, CTG, obtained significant improvements in BFP, LM, CMJ, 1RM squat, RE12, RE14, VO₂max, and AnT. RSSTG obtained improvements significantly higher than ETG in CMJ, 1RM squat, and RE14. ETG results were significantly better than those attained by RSSTG in AnT. Moreover, CTG marks were significantly higher than those obtained by ETG in CMJ and RE14.

CONCLUSION

Performing a 12-week concurrent training program integrated into the ATR periodization system effectively improves body composition and performance variables that can be obtained with exclusive running-specific strength and endurance training in recreational runners aged 30 to 40. Running-specific strength training enhances maximum and explosive strength and RE, whereas exclusive endurance training improves VO₂max, AnT, and RE. Performing concurrent training on non-consecutive days effectively prevents the strength and endurance adaptations attained with single-mode exercise from being attenuated. The ATR periodization system is useful in improving recreational endurance athletes' performance parameters, especially when performing concurrent training programs.

Effects of supervised high-intensity hardstyle kettlebell training on grip strength and health-related physical fitness in insufficiently active older adults: the BELL pragmatic controlled trial

The Ballistic Exercise of the Lower Limb (BELL) trial examined the efficacy and safety of a pragmatic hardstyle kettlebell training program in older adults. Insufficiently active men and women aged 59–79 years, were recruited to a 6-month repeated measures study, involving 3-months usual activity and 3-months progressive hardstyle kettlebell training. Health-related physical fitness outcomes included: grip strength [GS], 6-min walk distance [6MWD], resting heart rate [HR], stair-climb [SC], leg extensor strength [LES], hip extensor strength [HES], Sit-To-Stand [STS], vertical jump [CMVJ], five-times floor transfer [5xFT], 1RM deadlift, body composition (DXA), attendance, and adverse events. Sixteen males (68.8 ± 4.6 yrs, 176.2 ± 7.8 cm, 90.7 ± 11.0 kg, 29.2 ± 2.6 kg/m²) and sixteen females (68.6 ± 4.7 yrs, 163.9 ± 5.4 cm, 70.4 ± 12.7 kg, 26.3 ± 4.9 kg/m²) were recruited. Compliance with the supervised exercise program was very high (91.5%). Kettlebell training increased GS (R: MD = 7.1 kg 95% CI [4.9, 9.3], L: MD = 6.3 kg 95% CI [4.1, 8.4]), 6MWD (41.7 m, 95% CI [17.9, 65.5]), 1RM (16.2 kg, 95% CI [2.4, 30.0]), 30 s STS (3.3 reps, 95% CI [0.9, 5.7]), LES (R: MD = 61.6 N, 95% CI [4.4, 118.8]), HES (L: MD = 21.0 N,95% CI [4.2,37.8]), appendicular skeletal lean mass (MD = 0.65 kg, 95% CI [0.08, 1.22]), self-reported health change (17.1%, 95% CI [4.4, 29.8]) and decreased SC time (2.7 s, 95% CI [0.2, 5.2]), 5xFT time (6.0 s, 95% CI [2.2, 9.8]) and resting HR (7.4 bpm, 95% CI [0.7, 14.1]). There were four non-serious adverse events. Mean individual training load for group training sessions during the trial was 100,977 ± 9,050 kg. High-intensity hardstyle kettlebell training was well tolerated and improved grip strength and measures of health-related physical fitness in insufficiently active older adults.

Trial registration: Prospectively registered: 20/08/2019, Australian New Zealand Clinical Trials Registry (ACTRN12619001177145).

Handcycling Training in Men with Spinal Cord Injury Increases Tolerance To High Intensity Exercise

Individuals with spinal cord injury are characterised by reduced physical capacity as compared to able-bodied persons, and are at risk of developing cardiovascular disease. The study aimed to evaluate the differences in physiological responses to an exercise test in handcycling-trained vs. able-bodied-trained and non-trained men. Eight males with spinal cord injury who were trained in handcycling, eighteen able-bodied males who were trained in powerlifting, and fourteen physically active non-athletes performed a graded arm crank ergometer test. The following physiological indices were measured before and during the test: heart rate, oxygen uptake, and blood lactate concentrations. Aerobic capacity was significantly higher in athletes with spinal cord injury compared to able-bodied athletes (p<0.01) and the control group (p<0.01). The heart rate achieved by handcycling-trained athletes was significantly lower as compared to powerlifters (p<0.01), however, the oxygen pulse was significantly higher (p<0.05). Handcycling-trained athletes reached significantly higher peak power (Pmax) during the graded arm exercise in comparison with powerlifters, and significantly higher post exercise blood lactate concentration (p<0.05). The lactate threshold was observed at a significantly higher P in individuals with spinal cord injury compared to able-bodied-trained (p<0.05) and non-trained men (p<0.001). Athletes with spinal cord injury were found to have excellent aerobic capacity and better physiological adaptation to the maximal graded exercise test as compared to able-bodied-trained men. These findings emphasize the importance of regular physical exercise and its potential therapeutic role in the prevention of cardiovascular disease in patients with spinal cord injury.

Cycle ergometer training and resistance training similarly increase muscle strength in trained men

The aim of this study was to compare two different maximal intensity exercise modality training protocols of similar durations on muscle strength, cardiorespiratory fitness, and lower limb composition in recreationally trained men. Twenty-five trained men (28.9 ± 5.6 years) were randomly divided into Cycle ergometer (4 sets of 30 seconds sprints) and Leg press (4 sets of 10-12 repetitions to momentary failure). Both groups trained three times a week for 5 weeks. Before and after the training period, the participants performed a 10-repetition maximum (10RM) test for knee extension, an incremental exercise test on a treadmill for time to exhaustion (TTE) and peak oxygen consumption (V˙O_2peak) and underwent dual energy X-ray absorptiometry to assess lower limb composition. Knee extension 10RM and TTE increased in both groups with no statistically significant between group (p = 0.614 and p = 0.210). Only cycle ergometer group increased V˙O_2peak (p ₌ 0,012). For all lower limb composition outcomes, changes were minimal. The results suggest that 5 weeks of effort and duration matched exercise protocols using cycle ergometer training or leg press may produce similar strength adaptations.

Sex dimorphism in cardiac and aerobic capacities: The influence of body composition

OBJECTIVE

The contribution of body composition to sex differences in strong prognostic cardiorespiratory variables remains unresolved. This study aimed to elucidate whether body composition determines sex differences in cardiac and oxygen (O₂ ) uptake responses to incremental exercise.

METHODS

Healthy, moderately active women and men (n = 60, age = 60.7 [12.3] years) matched by age and cardiorespiratory fitness were included. Body composition was determined via dual-energy x-ray absorptiometry. Transthoracic echocardiography and O₂ uptake were assessed at rest and throughout incremental exercise with established methods. Major cardiac and pulmonary outcomes were normalized by body surface area (BSA), total lean body mass (LBM), or leg LBM.

RESULTS

Women presented with smaller anthropometrical indices (height, weight, BSA) and LBM compared with men (p < 0.001). Peak exercise cardiac dimensions and output (i.e., peak cardiac outout [Q_peak ]), commonly normalized by BSA, were reduced in women relative to men (p ≤ 0.019). Cardiac sex differences were abolished after normalization by total or leg LBM (p ≥ 0.115). Strong linear relationships of total and leg LBM with Q_peak and peak oxygen uptake were detected exclusively in women (r ≥ 0.53, p ≤ 0.003), independent of body fat percentage.

CONCLUSIONS

Total and leg LBM stand out as strong independent determinants of cardiac and aerobic capacities in women, regardless of body fat percentage, relationships that are not present in age- and fitness-matched men.

Toward Predicting Human Performance Outcomes From Wearable Technologies: A Computational Modeling Approach

Wearable technologies for measuring digital and chemical physiology are pervading the consumer market and hold potential to reliably classify states of relevance to human performance including stress, sleep deprivation, and physical exertion. The ability to efficiently and accurately classify physiological states based on wearable devices is improving. However, the inherent variability of human behavior within and across individuals makes it challenging to predict how identified states influence human performance outcomes of relevance to military operations and other high-stakes domains. We describe a computational modeling approach to address this challenge, seeking to translate user states obtained from a variety of sources including wearable devices into relevant and actionable insights across the cognitive and physical domains. Three status predictors were considered: stress level, sleep status, and extent of physical exertion; these independent variables were used to predict three human performance outcomes: reaction time, executive function, and perceptuo-motor control. The approach provides a complete, conditional probabilistic model of the performance variables given the status predictors. Construction of the model leverages diverse raw data sources to estimate marginal probability density functions for each of six independent and dependent variables of interest using parametric modeling and maximum likelihood estimation. The joint distributions among variables were optimized using an adaptive LASSO approach based on the strength and directionality of conditional relationships (effect sizes) derived from meta-analyses of extant research. The model optimization process converged on solutions that maintain the integrity of the original marginal distributions and the directionality and robustness of conditional relationships. The modeling framework described provides a flexible and extensible solution for human performance prediction, affording efficient expansion with additional independent and dependent variables of interest, ingestion of new raw data, and extension to two- and three-way interactions among independent variables. Continuing work includes model expansion to multiple independent and dependent variables, real-time model stimulation by wearable devices, individualized and small-group prediction, and laboratory and field validation.

Indicators of response to exercise training: a systematic review and meta-analysis

BACKGROUND

Means-based analysis of maximal rate of oxygen consumption (VO2max) has traditionally been used as the exercise response indicator to assess the efficacy of endurance (END), high intensity interval (HIIT) and resistance exercise training (RET) for improving cardiorespiratory fitness and whole-body health. However, considerable heterogeneity exists in the interindividual variability response to the same or different training modalities.

OBJECTIVES

We performed a systematic review and meta-analysis to investigate exercise response rates in the context of VO2max: (1) in each training modality (END, HIIT and RET) versus controls, (2) in END versus either HIIT or RET and (3) exercise response rates as measured by VO2max versus other indicators of positive exercise response in each exercise modality.

METHODS

Three databases (EMBASE, MEDLINE, CENTRAL) and additional sources were searched. Both individual response rate and population average data were incorporated through continuous data, respectively. Of 3268 identified manuscripts, a total of 29 studies were suitable for qualitative synthesis and a further 22 for quantitative. Stratification based on intervention duration (less than 12 weeks; more than or equal to 12 weeks) was undertaken.

RESULTS

A total of 62 data points were procured. Both END and HIIT training exhibited differential improvements in VO2max based on intervention duration. VO2max did not adequately differentiate between END and HIIT, irrespective of intervention length. Although none of the other exercise response indicators achieved statistical significance, LT and HRrest demonstrated common trajectories in pooled and separate analyses between modalities. RET data were highly limited. Heterogeneity was ubiquitous across all analyses.

CONCLUSIONS

The potential for LT and HRrest as indicators of exercise response requires further elucidation, in addition to the exploration of interventional and intrinsic sources of heterogeneity.

Effect of different types of regular exercise on physical fitness in adults with overweight or obesity: Systematic review and meta-analyses

This systematic review examined the effect of exercise training interventions on physical fitness in adults with overweight or obesity and compared the effectiveness of different types of exercise training. Four electronic databases were searched. Articles were included if they described randomized controlled trials of exercise training interventions and their effect on maximal oxygen consumption or muscle strength in adults with overweight or obesity. Changes in outcome parameters were analyzed using random effects meta-analyses for different training types (aerobic, resistance, combined aerobic plus resistance, and high-intensity interval training). Eighty-eight articles satisfied the inclusion criteria of which 66 (3964 participants) could be included in the meta-analyses. All training types increased VO_2max (mean difference 3.82 ml/min/kg (95% CI 3.17, 4.48), P < 0.00001; I² = 48%). In direct comparisons, resistance training was less effective in improving VO_2max than aerobic training, HIIT was slightly more effective than aerobic training, and no difference between aerobic and combined aerobic plus resistance training was found. For muscle strength benefits, incorporation of resistance exercise in the training program is indicated. Exercise training increases VO_2max and muscle strength in adults with overweight or obesity. Differences between training types should be weighed with other needs and preferences when health professionals advise on exercise training to improve physical fitness.

Metabolic Profile of Reciprocal Supersets in Young, Recreationally Active Women and Men

ABSTRACT

Realzola, RA, Mang, ZA, Millender, DJ, Beam, JR, Bellovary, BN, Wells, AD, Houck, JM, and Kravitz, L. Metabolic profile of reciprocal supersets in young, recreationally active females and males. J Strength Cond Res XX(X): 000-000, 2020-Reciprocal supersets (RSSs) are a time-efficient style of resistance exercise (RE) that consist of performing 2 consecutive exercises with opposing muscle groups while limiting rest times between them. Previous research in men indicates a RSS has an increased physiological response when compared with traditional RE (TRAD). No between-sex comparison of metabolic data for RSSs exists. The purpose of this study was to create a metabolic profile for RSSs in men and women. Eighteen resistance-trained individuals underwent 2 bouts of volume-load equated RE: RSS and TRAD. Reciprocal superset exercises were split into 3 clusters: (a) hexagonal bar deadlift superset with leg press, (b) chest press superset with seated row, and (c) overhead dumbbell press superset with latissimus dorsi pull-downs. The TRAD protocol, doing the same exercises, emulated hypertrophy emphasis training. Oxygen uptake (V[Combining Dot Above]O2), heart rate (HR), blood lactate ([BLa]), rate of perceived exertion (RPE), and excess post-exercise oxygen consumption (EPOC) were measured. Aerobic and anaerobic energy expenditure were estimated using V[Combining Dot Above]O2 and lactate, respectively. The level of significance set for this study was p ≤ 0.05. Regardless of sex, a RSS elicited significantly greater average V[Combining Dot Above]O2, HR, [BLa], RPE, and anaerobic and aerobic energy expenditures, and was completed in a shorter time compared with TRAD (p ≤ 0.05). When compared with women, men had significantly greater EPOC, average [BLa], and anaerobic and aerobic energy expenditures during RSSs (p ≤ 0.05). The average [BLa] and aerobic energy expenditure of the men were also significantly greater than the women during TRAD (p ≤ 0.05). This study suggests that a RSS is a metabolically demanding RE session that may elicit increases in musculoskeletal, cardiorespiratory, and physiological adaptations while decreasing the duration of exercise.

Effects of Chair-Based, Low-Load Elastic Band Resistance Training on Functional Fitness and Metabolic Biomarkers in Older Women

Strength training can improve myriad health parameters in elderly cohorts. Although potentially more appropriate for the elderly, low-load resistance training protocols have been less investigated. We aimed to examine the effects of 12 weeks of chair-based, low-load resistance training with elastic band (EBT) on functional fitness and metabolic biomarkers in older women. One hundred sixty-eight women were allocated randomly to an elastic band resistance training (EBT, n = 86, 75.7 ± 8.9 years, 71.3 ± 12.2 kg) or a control group (CON, n = 82, 74.5 ± 8.2years, 70.6 ± 12.0 kg). RT protocol consisted of periodized chair-based, low-load whole-body resistance exercises (2 sets, 12-15 repetitions, 40-60% of one repetition maximum-1RM) using an elastic band, twice weekly for 12 weeks. The resistance training program was generally designed to maintain internal load over time, provided with increasing intensity using various elastic bands (Thera-Band). Functional fitness (30-s Chair Stand,30-s Arm Curl, 2-min Step Test, Chair Sit-and-Reach, Back Scratch, 8-Foot Up-and-Go, Handgrip Strength) and metabolic markers (Fasting blood glucose, triglycerides, total cholesterol, high (HDL) and low (LDL) density lipoprotein) were measured before and after the training period. To detect pre/post intervention changes and between group- differences 2x2 repeated measures ANOVA was applied. Significant improvements over time for all fitness variables for EBT comparing to CON were obtained (F = 12.78, p < 0.05 for 30-s Chair Stand; F = 14.04, p < 0.05 for 30-s Arm Curl; F = 5.18, p < 0.05 for 2-min Step Test; F = 10.90, p < 0.05 for Chair Sit-and-Reach; F = 16.57, p < 0.05 for Back Scratch; F = 11.79, p < 0.05 for 8-foot Up-and-Go; and F = 29.25, p < 0.05 for Handgrip Strength). In addition, significant improvements over time for all but one (triglycerides) biomarkers for EBT comparing to CON were obtained (F = 7.30, p < 0.05 for blood sugar levels; F = 13.36, p < 0.05 for total cholesterol; F = 8.61, p < 0.05 for HDL; and F = 11.53, p < 0.05 for LDL). Furthermore, the participants' adherence to training sessions of over 90% was reported. In conclusion, 12 weeks of EBT is safe and beneficial for improving health-related fitness and metabolic biomarkers in older women and seems to be viable model to ensure a high training adherence rate.

Chronic Resistance Exercise Improves Functioning and Reduces Toll-Like Receptor Signaling in Elderly Patients With Postoperative Deconditioning

OBJECTIVE

Elderly patients continue to experience low levels of mobility during and following postoperative hospitalization that lead to persistent physical decline. Therefore, here we compared chronic resistance (CR) exercise against chronic aerobic (CA) exercise in ameliorating postoperative functioning and reducing proinflammatory muscular Toll-like receptor (TLR)-associated signaling in elderly postoperative patients.

METHODS

We conducted a prospective, randomized trial comparing the effects of 3 exercise programs (CR, CA, and CR + CA) in 66 elderly patients recovering from recent hip, femur, or pelvic fracture repair surgery. The primary outcomes were changes in anatomic/physical performance parameters (ie, maximal oxygen intake, endurance, quadriceps cross-sectional area, and maximum knee-extensor force). The secondary outcomes were changes in TLR/nuclear factor kappa beta signaling pathway marker expression.

RESULTS

Three of the 4 anatomic/physical performance parameters significantly improved for the CR and CR + CA cohorts. Muscular expression of myeloid differentiation primary response gene 88, transforming growth factor beta-activated kinase 1 (TLR signaling pathway markers), p50, p65, tumor necrosis factor α, and interleukin 6 (nuclear factor kappa beta signaling pathway markers) all showed significant reductions after CR and CR + CA. Serum expression of 2 key TLR4 ligands, heat shock protein 70 and serum amyloid A, also showed significant reductions after CR and CR + CA.

CONCLUSIONS

Three months of CR or CR + CA improves maximal oxygen consumption, quadriceps cross-sectional area, and maximum knee-extensor force while lowering muscular proinflammatory signaling markers in elderly adults with postoperative deconditioning.

Perspective: Pragmatic Exercise Recommendations for Older Adults: The Case for Emphasizing Resistance Training

Optimal health benefits from exercise are achieved by meeting both aerobic and muscle strengthening guidelines, however, most older adults (OAs) do not exercise and the majority of those who do only perform one type of exercise. A pragmatic solution to this problem may be emphasizing a single exercise strategy that maximizes health benefits. The loss of muscle mass and strength at an accelerated rate are hallmarks of aging that, without intervention, eventually lead to physical disability and loss of independence. Additionally, OAs are at risk of developing several chronic diseases. As such, participating in activities that can maintain or increase muscle mass and strength, as well as decrease chronic disease risk, is essential for healthy aging. Unfortunately, there is a widely held belief that adaptations to aerobic and resistance exercise are independent of each other, requiring the participation of both types of exercise to achieve optimal health. However, we argue that this assertion is incorrect, and we discuss crossover adaptations of both aerobic and resistance exercise. Aerobic exercise can increase muscle mass and strength, though not consistently and may be limited to exercise that overloads a particular muscle group, such as stationary bicycling. In contrast, resistance exercise is effective at maintaining muscle health with increasing age, and also has significant effects on cardiovascular disease (CVD) risk factors, type 2 diabetes (T2D), cancer, and mortality. We posit that resistance exercise is the most effective standalone exercise strategy for improving overall health in OAs and should be emphasized in future guidelines.

Effects of 6 Weeks of Traditional Resistance Training or High Intensity Interval Resistance Training on Body Composition, Aerobic Power and Strength in Healthy Young Subjects: A Randomized Parallel Trial

Consistent practice of physical activity has well known positive effects on general health; however, time for exercise remains one major barrier for many. An acute bout of high intensity interval resistance training (HIIRT) increases acute resting energy expenditure (REE) and decreases respiratory ratio (RR), suggesting its potential role on weight loss and increased fatty acid oxidation. The aim of this study was to test the long-term effect of HIIRT on body composition, lipid profile and muscle strength using a randomized parallel trial. Twenty healthy young adults (22.15 1.95 years) were randomized to perform either a HIIRT (N = 11) protocol, consisting of three sets of 6 repetitions at 6 repetition maximum (RM) and then 20 seconds of rest between repetitions until exhaustion repeated for 3 times with 2'30″ rest between sets or a traditional training (TRT, N = 9) protocol of 3 sets of 15 reps with 75 sec of rest between sets. Body composition, resting energy metabolism, aerobic capacity, muscle strength and blood measurements were taken before and after 8 weeks of training. Both protocols enhanced muscle strength, but only HIIRT improved endurance strength performance (+22.07%, p < 0.05) and lean body mass (+2.82%, p < 0.05). REE and RR were unaltered as lipid profile. HIIRT represents a valid training method to improve muscle strength and mass, but its role on body weight control was not confirmed.

Effects of Aerobic and Resistance Exercise on Cardiovascular Parameters for People Living With HIV: A Meta-analysis

People living with HIV (PLWH) have limited exercise capacity because of anemia, neuromuscular disorders, and pulmonary limitations. We used a meta-analysis to examine the effect of aerobic and resistance exercise alone and in combination on cardiovascular parameters. Subgroup meta-analyses were conducted and long-term effects of exercise were investigated. A systematic literature search was conducted up to July/August 2017. The Physiotherapy Evidence Database-scale was used to rate quality and assess the risk of bias on the papers. Standardized mean differences (SMDs) were calculated to assess the effect of exercise. Posttreatment comparison between the exercise and control groups revealed moderate and large effect sizes in favor of the intervention group for VO2max (SMD = 0.66, p < .0001) and the 6-minute walk test (SMD = 1.11, p = .0001). Exercise had a positive effect on cardiovascular parameters in PLWH. Exercise can be a prevention factor for PLWH dealing with multiple comorbidities.

Twelve Weeks of Combined Resistance and Aerobic Exercise Improves Cardiometabolic Biomarkers and Enhances Red Blood Cell Hemorheological Function in Obese Older Men: A Randomized Controlled Trial

The present study examined the effect of a 12-week combined resistance and aerobic exercise training program on cardiometabolic biomarkers and red blood cell (RBC) hemorheological function in 20 obese older men (mean age: 68.8 ± 0.9 years). Subjects were randomly divided into two groups (exercise intervention [EXP; n = 10] and control [CON; n = 10]). The EXP subjects performed resistance and aerobic exercise training program three times per week for 12 weeks, and the CON subjects maintained their regular lifestyle during the intervention period. Body composition was estimated using bioelectrical impedance analysis equipment. Cardiometabolic biomarkers (glucose, insulin, homeostasis model assessment-estimated insulin resistance (HOMA-IR), HOMA β-cell function, and leptin) and RBC hemorheological parameters (RBC deformability and aggregation) were analyzed. Percent body fat decreased significantly in the EXP group during the intervention period but increased significantly in the CON group. Insulin increased significantly in the CON group over the 12-week period and both insulin and HOMA-IR were significantly higher in the CON group than in the EXP group at post-test. RBC deformability (RBC EI_3Pa) and aggregation (RBC AI_3Pa) improved significantly only in the EXP group. The present study suggests that combined exercise training can be useful for improving cardiometabolic biomarkers and RBC hemorheological parameters in obese older men and may help prevent metabolic syndrome and cardiovascular diseases.

The effects of same-session combined exercise training on cardiorespiratory and functional fitness in older adults: a systematic review and meta-analysis

Endurance and strength training are effective strategies for counteracting age-associated reductions in physical performance in older adults, with a combination of both exercise modes recommended to maximise potential fitness benefits. This meta-analysis sought to quantify the effects of same-session combined endurance and strength training on fitness in adults aged over 50 years. Five electronic databases were searched with studies required to include one of the following outcome measures: VO_2peak, 6-min walk test (6MWT), 8-ft timed up-and-go (TUG), and 30-s chair stand. Separate random-effects meta-analyses compared combined training with (1) no-exercise control, (2) endurance training, and (3) strength training with probabilistic magnitude-based inferences subsequently applied. Twenty-seven studies involving 1346 subjects with a mean age of 68.8 years (range 54–85 years) were included in the analysis. The meta-analysed effect on VO_2peak was a moderately beneficial effect for the combined training compared to no-exercise controls (3.6 mL kg⁻¹ min⁻¹; ± 95% confidence limits 0.8 mL kg⁻¹ min⁻¹) with additional increases for studies with greater proportions of female participants and shorter training interventions. Combined training also had small-to-moderately beneficial effects on VO_2peak when compared to endurance training (0.8 mL kg⁻¹ min⁻¹; ± 1.0 mL kg⁻¹ min⁻¹), 30-s chair stand when compared with strength training (1.1 repetitions; ± 0.5 repetitions) and on TUG (0.8 s; ± 0.7 s), 30-s chair stand (2.8 repetitions; ± 1.7 repetitions), and 6MWT (31.5 m; ± 22.4 m) when compared to no-exercise controls. All other comparisons were unclear. Same-session combined training can induce clinically relevant fitness improvements in older adults.

Comparisons of Resistance Training and "Cardio" Exercise Modalities as Countermeasures to Microgravity-Induced Physical Deconditioning: New Perspectives and Lessons Learned From Terrestrial Studies

Prolonged periods in microgravity (μG) environments result in deconditioning of numerous physiological systems, particularly muscle at molecular, single fiber, and whole muscle levels. This deconditioning leads to loss of strength and cardiorespiratory fitness. Loading muscle produces mechanical tension with resultant mechanotransduction initiating molecular signaling that stimulates adaptations in muscle. Exercise can reverse deconditioning resultant from phases of detraining, de-loading, or immobilization. On Earth, applications of loading using exercise models are common, as well as in μG settings as countermeasures to deconditioning. The primary modalities include, but are not limited to, aerobic training (or "cardio") and resistance training, and have historically been dichotomized; the former primarily thought to improve cardiorespiratory fitness, and the latter primarily improving strength and muscle size. However, recent work questions this dichotomy, suggesting adaptations to loading through exercise are affected by intensity of effort independent of modality. Furthermore, similar adaptations may occur where sufficient intensity of effort is used. Traditional countermeasures for μG-induced deconditioning have focused upon engineering-based solutions to enable application of traditional models of exercise. Yet, contemporary developments in understanding of the applications, and subsequent adaptations, to exercise induced muscular loading in terrestrial settings have advanced such in recent years that it may be appropriate to revisit the evidence to inform how exercise can used in μG. With the planned decommissioning of the International Space Station as early as 2024 and future goals of manned moon and Mars missions, efficiency of resources must be prioritized. Engineering-based solutions to apply exercise modalities inevitably present issues relating to devices mass, size, energy use, heat production, and ultimately cost. It is necessary to identify exercise countermeasures to combat deconditioning while limiting these issues. As such, this brief narrative review considers recent developments in our understanding of skeletal muscle adaptation to loading through exercise from studies conducted in terrestrial settings, and their applications in μG environments. We consider the role of intensity of effort, comparisons of exercise modalities, the need for concurrent exercise approaches, and other issues often not considered in terrestrial exercise studies but are of concern in μG environments (i.e., O2 consumption, CO2 production, and energy costs of exercise).

Resistance Training for Older Adults in Cardiac Rehabilitation

Cardiac rehabilitation plays a key role in the care of older patients after a coronary event. Hospitalizations are prevented and quality of life, exercise capacity, and physical function are improved. Almost 50% of cardiac rehabilitation participants are older adults (>65 years), many of whom are frail or deconditioned. Resistance training, as a component of cardiac rehabilitation, improves muscle strength, endurance, and physical function. The purpose of this review is to describe the effects of resistance training in cardiac rehabilitation for older adults with a particular focus on physical function.

Association among 2-min step test, functional level and diagnosis of dementia

Aerobic capacity declines significantly throughout life, beginning at the age of 30 years and accelerating from 60 years, where a decline of 17% per decade is expected thereafter.

Objective

To investigate the association between aerobic capacity and a diagnosis of mild cognitive impairment (MCI), mild AD or moderate AD in older adults, considering the risk classification of functional loss of the Step test.

Methods

In this cross-sectional study, 93 patients (age >60 years) were evaluated (Healthy=36; MCI=18, AD=39). The step test was used to assess aerobic capacity, while overall cognitive status was measured using the MMSE. The groups were divided according to the risk classifications of functional loss into below or above the standard cut-off point for aerobic capacity.

Results

Subjects in the functional loss risk group were approximately ten to fourteen times more likely to be diagnosed with mild (OR:10.7; p=0.001) or moderate (OR.=14.7; p=0.002) AD than their fitter counterparts. Low aerobic fitness was also associated with the MCI condition (OR=4.5; p=0.05), but only after controlling for educational level, age and sex. In the overall sample (N=93), there was an association between aerobic capacity and MMSE performance (R²=0.35; p<0.001) after controlling for confounding variables.

Conclusion

low aerobic capacity was associated with cognitive decline, and older adults at risk of functional loss on the STEP test had greater chance of being diagnosed with MCI or AD after controlling for age, sex and education.

Comparison of time-matched aerobic, resistance, or concurrent exercise training in older adults

A supervised 12-week intervention of time-matched aerobic vs resistance versus concurrent exercise training was employed to investigate mode- and time course-specific effects of exercise training in older adults. Community-dwelling men and women (n = 84; M/F, 45/39; 69.3 ± 3.5 years; 26.4 ± 3.8 kg m^-2 ) were randomly assigned (n = 21 each) to either non-exercise control (CON), aerobic exercise only (AER), resistance exercise only (RES), or concurrent aerobic and resistance exercise (CEX). Training groups trained three times per week, each performing 72 minutes of active exercise time per week. Body composition, physical and cognitive function, and markers of metabolic health were assessed before (PRE), and after 6 (MID) and 12 (POST) weeks of exercise training. Hand-grip strength, 1RM chest press, and arm LBM were improved by both RES and CEX, but not AER. Aerobic fitness increased in AER and RES, but not CEX. Cognitive function improved in all groups, but occurred earlier (ie, at MID) in AER. CEX improved gait speed and lower limb strength and reduced trunk fat compared to either AER or RES. Leg LBM was unchanged in any group. Temporal patterns were observed as early as 6 weeks of training (gait speed, upper and lower limb strength, aerobic fitness), whereas others were unchanged until 12 weeks (hand-grip strength, timed up-and-go, sit-to-stand). Compared to either aerobic or resistance exercise training alone, concurrent exercise training is as efficacious for improving a range of health-related parameters and is more efficacious for increasing gait speed and lower limb strength, and decreasing trunk fat in older adults.

Comparison of structured and unstructured physical activity training on predicted VO2max and heart rate variability in adolescents - a randomized control trial

BACKGROUND

Physical inactivity contributes to many health issues. The WHO-recommended physical activity for adolescents encompasses aerobic, resistance, and bone strengthening exercises aimed at achieving health-related physical fitness. Heart rate variability (HRV) and maximal aerobic capacity (VO2max) are considered as noninvasive measures of cardiovascular health. The objective of this study is to compare the effect of structured and unstructured physical training on maximal aerobic capacity and HRV among adolescents.

METHODS

We designed a single blinded, parallel, randomized active-controlled trial (Registration No. CTRI/2013/08/003897) to compare the physiological effects of 6 months of globally recommended structured physical activity (SPA), with that of unstructured physical activity (USPA) in healthy school-going adolescents. We recruited 439 healthy student volunteers (boys: 250, girls: 189) in the age group of 12-17 years. Randomization across the groups was done using age and gender stratified randomization method, and the participants were divided into two groups: SPA (n=219, boys: 117, girls: 102) and USPA (n=220, boys: 119, girls: 101). Depending on their training status and gender the participants in both SPA and USPA groups were further subdivided into the following four sub-groups: SPA athlete boys (n=22) and girls (n=17), SPA nonathlete boys (n=95) and girls (n=85), USPA athlete boys (n=23) and girls (n=17), and USPA nonathlete boys (n=96) and girls (n=84).

RESULTS

We recorded HRV, body fat%, and VO2 max using Rockport Walk Fitness test before and after the intervention. Maximum aerobic capacity and heart rate variability increased significantly while heart rate, systolic blood pressure, diastolic blood pressure, and body fat percentage decreased significantly after both SPA and USPA intervention. However, the improvement was more in SPA as compared to USPA.

CONCLUSIONS

SPA is more beneficial for improving cardiorespiratory fitness, HRV, and reducing body fat percentage in terms of magnitude than USPA in adolescent individuals irrespective of their gender and sports activities.

Similar acute physiological responses from effort and duration matched leg press and recumbent cycling tasks

The present study examined the effects of exercise utilising traditional resistance training (leg press) or ‘cardio’ exercise (recumbent cycle ergometry) modalities upon acute physiological responses. Nine healthy males underwent a within session randomised crossover design where they completed both the leg press and recumbent cycle ergometer conditions. Conditions were approximately matched for effort and duration (leg press: 4 × 12RM using a 2 s concentric and 3 s eccentric repetition duration controlled with a metronome, thus each set lasted  60 s; recumbent cycle ergometer: 4 × 60 s bouts using a resistance level permitting 80–100 rpm but culminating with being unable to sustain the minimum cadence for the final 5–10 s). Measurements included VO₂, respiratory exchange ratio (RER), blood lactate, energy expenditure, muscle swelling, and electromyography. Perceived effort was similar between conditions and thus both were well matched with respect to effort. There were no significant effects by ‘condition’ in any of the physiological responses examined (all p > 0.05). The present study shows that, when both effort and duration are matched, resistance training (leg press) and ‘cardio’ exercise (recumbent cycle ergometry) may produce largely similar responses in VO₂, RER, blood lactate, energy expenditure, muscle swelling, and electromyography. It therefore seems reasonable to suggest that both may offer a similar stimulus to produce chronic physiological adaptations in outcomes such as cardiorespiratory fitness, strength, and hypertrophy. Future work should look to both replicate the study conducted here with respect to the same, and additional physiological measures, and rigorously test the comparative efficacy of effort and duration matched exercise of differing modalities with respect to chronic improvements in physiological fitness.

Combined sprint and resistance training abrogates age differences in somatotropic hormones

The aim of this investigation was to compare serum growth hormone (GH), insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein-3 (IGFBP-3) in response to a combined sprint and resistance training (CSRT) program in young and middle-aged men.Thirty-eight healthy, moderately trained men participated in this study. Young and middle-aged men were randomly assigned to, a young training group (YT = 10, 21.4±1.2yrs) ora young control group (YC = 9, 21.6±1.8 yrs), a middle-aged training group (MAT = 10, 40.4±2.1 yrs) or a middle-aged control group (MAC = 9, 40.5±1.8 yrs). Participants performed the Wingate Anaerobic Test (WAnT) before and after a 13-week CSRT program (three sessions per week). Blood samples were collected at rest, after warm-up, immediately post-WAnT, and 10 min post-WAnT. CSRT induced increases in GH at rest and in response to the WAnT in YT and MAT (P<0.05). CSRT-induced increases were observed for IGF-1 and IGFBP-3 at rest in MAT only (P<0.05). Pre-training, GH, IGF-1 and IGFBP-3 were significantly higher at rest and in response to the WAnT in young participants as compared to their middle-aged counterparts (P<0.05). Post-training, YT and MAT had comparable basal GH (P>0.05). In response to the WAnT, amelioration of the age-effect was observed between YT and MAT for IGF-1 and IGF-1/IGFBP-3 ratio following CSRT (P>0.05). These data suggest that CSRT increases the activity of the GH/IGF-1 axis at rest and in response to the WAnT in young and middle-aged men. In addition, CSRT reduces the normal age-related decline of somatotropic hormones in middle-age men.

Acute Responses to Resistance and High-Intensity Interval Training in Early Adolescents

Harris, NK, Dulson, DK, Logan, GRM, Warbrick, IB, Merien, FLR, and Lubans, DR. Acute responses to resistance and high-intensity interval training in early adolescents. J Strength Cond Res 31(5): 1177-1186, 2017-The purpose of this study was to compare the acute physiological responses within and between resistance training (RT) and high-intensity interval training (HIIT) matched for time and with comparable effort, in a school setting. Seventeen early adolescents (12.9 ± 0.3 years) performed both RT (2-5 repetitions perceived short of failure at the end of each set) and HIIT (90% of age-predicted maximum heart rate), equated for total work set and recovery period durations comprising of 12 "sets" of 30-second work followed by 30-second recovery (total session time 12 minutes). Variables of interest included oxygen consumption, set and session heart rate (HR), and rate of perceived exertion, and change in salivary cortisol (SC), salivary alpha amylase, and blood lactate (BL) from presession to postsession. Analyses were conducted to determine responses within and between the 2 different protocols. For both RT and HIIT, there were very large increases pretrial to posttrial for SC and BL, and only BL increased greater in HIIT (9.1 ± 2.6 mmol·L) than RT (6.8 ± 3.3 mmol·L). Mean set HR for both RT (170 ± 9.1 b·min) and HIIT (179 ± 5.6 b·min) was at least 85% of HRmax. V[Combining Dot Above]O2 over all 12 sets was greater for HIIT (33.8 ± 5.21 ml·kg·min) than RT (24.9 ± 3.23 ml·kg·min). Brief, repetitive, intermittent forays into high but not supramaximal intensity exercise using RT or HIIT seemed to be a potent physiological stimulus in adolescents.

Effects of resistance training frequency on cardiorespiratory fitness in older men and women during intervention and follow-up

This study investigated the effects of resistance training (RT) performed with different frequencies, including a follow-up period, on cardiorespiratory fitness in healthy older individuals. Eighty-eight men and women (69±3years, 167±9cm and 78±14kg) were randomly placed into four groups: training one- (M1=11, W1=12), two- (M2=7, W2=14), or three- (M3=11, W3=13) times-per-week or a non-training control group (MCon=11, WCon=9). During months 1-3, all subjects trained two-times-per-week while during the subsequent 6months, training frequency was set according to the group. Oxygen consumption (cycling economy: CE), gross efficiency (GE), blood lactate concentrations (La) and heart rate (HR) were evaluated during a submaximal cycle ergometer test. Hemoglobin (Hb), hematocrit (Hct), heart rate (HRrest) and body composition by DXA were also measured at rest. Maximal strength was measured by a 1-RM leg press test. Most improvements in CE, GE, La and HR occurred in all groups during months 1-3. No additional statistically significant improvements were observed during months 4-9, although effect sizes for the change in CE and GE at higher workloads indicated a dose-response pattern in men (CE at 75W: M1 g=0.13, M2 g=-0.58, M3 g=-0.89; 100W: M1 g=0.43, M2 g=-0.59, M3 g=-0.68) i.e. higher training frequency (two- and three-times-per-week versus one-time-per-week) led to greater improvements once the typical plateau in performance had occurred. Hb increased in W1 and W2, while no changes were observed in Hct or HRrest. 1-RM increased from months 1-3 in all intervention groups (except M2) and from month 4-9 only in M3 and in all women intervention groups. During follow-up, maximal strength was maintained but cycling economy returned to the baseline values in all training groups. These data indicate that RT led to significant improvements in cardiorespiratory fitness during the initial 3months of training. This was partly explained by the RT protocol performed but further improvements may require higher training frequency. These changes are likely to be originated by the improved cardiorespiratory functions rather than neuromuscular adaptations evidenced by a lack of significant relationship during the intervention as well as the divergent results during follow-up.