Cardiorespiratory Adaptations in Elderly Men Following Different Concurrent Training Regimes

The physiological and physical benefits of two types of concurrent training: a randomized controlled trial

BACKGROUND

It is widely acknowledged that aerobic exercise and strength training are crucial components of most workout programs. However, there is no consensus as to whether the effectiveness of exercises is affected by the sequence in which they are performed. Therefore, the overarching aim of the study was to understand the optimal order of two types of concurrent training program for 13 weeks by comparing the effectiveness of the training on body composition, predicated maximal oxygen uptake (VO2max), dynamic respiratory parameters and muscle strength in healthy middle-aged people.

METHODS

Thirty-three middle-aged individuals, who were categorized as moderately active based on their responses to International Physical Activity Questionnaires, underwent random allocation. The participants were randomly assigned into two groups: the Strength Training followed by Aerobic Training group (SAG, n = 16) and the Aerobic Training followed by Strength Training group (ASG, n = 17). Body composition, aerobic endurance, respiratory parameters, and upper and lower strength were assessed at baseline and after (post-test) a 13-week intervention. The chi-square test and the independent t-test were used to compare sociodemographic variables between the groups. A 2 × 2 analysis of variance (ANOVA) with repeated measures (group x measurement) was conducted. The study was retrospectively registered on clinicaltrials.gov in May of 2023 (clinicaltials.gov identifier: NCT05862415; in 04/25/2023).

RESULTS

Findings showed no significant differences between the group in the VO2max, FVC or FEV1 (F = 1.122, 0.028, 0.06, 2.483; p > 0.05, respectively). Intragroup analysis revealed changes in PEF compared to baseline in the ASG (F = 5.895; p < 0.05). Increases were observed in all strength parameters for both training programs.

CONCLUSIONS

The concurrent training effect on muscle composition, oxygen consumption and muscle strength specifically 1RM, in middle-aged individuals are equivocal, regardless of the exercise order. The results indicate that both exercise sequences can elicit similar benefits in terms of cardiovascular fitness, muscular strength, and endurance. This lack of difference suggests that the order of exercise does not play a significant role in determining the effectiveness of the workout or the subsequent physiological adaptations. CLINICALTIALS.

GOV IDENTIFIER

NCT05862415. Date of registration: 04/25/2023.

Effects of combined muscle power and endurance training with different volumes on functional and hemodynamic parameters in previously trained older adults

BACKGROUND

To promote optimal neuromuscular and cardiovascular gains in older adults, it seems crucial to investigate the effects of different combined training volumes in this population. Thus, the present study aimed to compare the effects of combined muscle power training (MPT) and endurance training (ET) with different volumes on functional and hemodynamic parameters in previously trained older adults.

METHODS

Twenty-five older adults were randomly assigned to either the lower-volume group (LVG; n = 13) or the higher-volume group (HVG; n = 12). In the LVG, participants performed 1 set of 6 repetitions for each exercise, followed by 10 min of walking exercise. In the HVG, participants performed 2 sets of 6 repetitions for each exercise, followed by 20 min of walking exercise. Lift from the ventral decubitus position (LPDV), timed up-and-go (TUG), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were assessed before and after 8 weeks.

RESULTS

Significant increases in LPDV test occurred in both groups after 8 weeks (p < 0.05). Additionally, significant improvements in TUG performance occurred in both groups from week 0 to week 8 (p < 0.05). However, no significant changes were observed between groups in functional parameters (p > 0.05). SBP and DBP remain unchanged (p > 0.05) in both groups over the experimental period.

CONCLUSIONS

These findings indicate that lower-volume and higher-volume of combined MPT and ET promoted improvements in functional parameters. This study has an important practical application, as it indicates that regardless of the volume (lower or higher), comparable improvements are observed in functional parameters in previously trained older adults.

Interindividual variability of adaptations following either traditional strength or power training combined to endurance training in older men: A secondary analysis of a randomized clinical trial

This study aimed to investigate the interindividual responses following two different concurrent training (CT) regimens in neuromuscular, cardiorespiratory and functional outcomes of older men. Thirty-five older men (65.8 ± 3.9 years) were randomly allocated into one of two CT groups: power training (PT) + high-intensity interval training (HIIT) (n = 17); or traditional strength training (TST) + HIIT (n = 18). Maximal dynamic strength (one-repetition maximum, 1RM), rate of force development at 100 milliseconds (RDF₁₀₀), countermovement jump power (CMJ), quadriceps femoris muscle thickness (QF MT), functional tests (sit-to-stand, timed-up-and-go, and stair climbing), and peak oxygen consumption (VO_2peak) were assessed pre-, post-8 and post-16 weeks of training. The Chi-squared test was used for assessing differences in the prevalence of responders (Rs), non-responders (NRs), and adverse responders (ARs). Similar prevalence of individual responses (Rs, NRs and ARs) between groups were observed after intervention in almost all outcomes: 1RM; power at CMJ; QF MT, and functional tests (P > 0.05). However, a significant difference in the distribution of Rs, NRs and ARs between groups was observed in the RFD₁₀₀ after 16 weeks (p = 0.003), with PT + HIIT group presenting high prevalence of Rs than TST + HIIT (100 % vs. 50 %). The inclusion of explosive-type of contractions in a concurrent training regime induces greater responsiveness in the RFD₁₀₀ in older men, while no differences compared to traditional strength training are observed in maximal strength, muscle size, VO_2peak, and functional performance.

A Systematic Review Examining the Approaches Used to Estimate Interindividual Differences in Trainability and Classify Individual Responses to Exercise Training

Background: Many reports describe statistical approaches for estimating interindividual differences in trainability and classifying individuals as "responders" or "non-responders." The extent to which studies in the exercise training literature have adopted these statistical approaches remains unclear. Objectives: This systematic review primarily sought to determine the extent to which studies in the exercise training literature have adopted sound statistical approaches for examining individual responses to exercise training. We also (1) investigated the existence of interindividual differences in trainability, and (2) tested the hypothesis that less conservative thresholds inflate response rates compared with thresholds that consider error and a smallest worthwhile change (SWC)/minimum clinically important difference (MCID). Methods: We searched six databases: AMED, CINAHL, EMBASE, Medline, PubMed, and SportDiscus. Our search spanned the aerobic, resistance, and clinical or rehabilitation training literature. Studies were included if they used human participants, employed standardized and supervised exercise training, and either: (1) stated that their exercise training intervention resulted in heterogenous responses, (2) statistically estimated interindividual differences in trainability, and/or (3) classified individual responses. We calculated effect sizes (ES_IR) to examine the presence of interindividual differences in trainability. We also compared response rates (n = 614) across classification approaches that considered neither, one of, or both errors and an SWC or MCID. We then sorted response rates from studies that also reported mean changes and response thresholds (n = 435 response rates) into four quartiles to confirm our ancillary hypothesis that larger mean changes produce larger response rates. Results: Our search revealed 3,404 studies, and 149 were included in our systematic review. Few studies (n = 9) statistically estimated interindividual differences in trainability. The results from these few studies present a mixture of evidence for the presence of interindividual differences in trainability because several ES_IR values lay above, below, or crossed zero. Zero-based thresholds and larger mean changes significantly (both p < 0.01) inflated response rates. Conclusion: Our findings provide evidence demonstrating why future studies should statistically estimate interindividual differences in trainability and consider error and an SWC or MCID when classifying individual responses to exercise training. Systematic Review Registration: [website], identifier [registration number].

Interference Phenomenon with Concurrent Strength and High-Intensity Interval Training-Based Aerobic Training: An Updated Model

Previous research has suggested that concurrent training (CT) may attenuate resistance training (RT)-induced gains in muscle strength and mass, i.e.' the interference effect. In 2000, a seminal theoretical model indicated that the interference effect should occur when high-intensity interval training (HIIT) (repeated bouts at 95-100% of the aerobic power) and RT (multiple sets at ~ 10 repetition maximum;10 RM) were performed in the same training routine. However, there was a paucity of data regarding the likelihood of other HIIT-based CT protocols to induce the interference effect at the time. Thus, based on current HIIT-based CT literature and HIIT nomenclature and framework, the present manuscript updates the theoretical model of the interference phenomenon previously proposed. We suggest that very intense HIIT protocols [i.e., resisted sprint training (RST), and sprint interval training (SIT)] can greatly minimize the odds of occurring the interference effect on muscle strength and mass. Thus, very intensive HIIT protocols should be implemented when performing CT to avoid the interference effect. Long and short HIIT-based CT protocols may induce the interference effect on muscle strength when HIIT bout is performed before RT with no rest interval between them.

An appraisal of the SDIR as an estimate of true individual differences in training responsiveness in parallel-arm exercise randomized controlled trials

Calculating the standard deviation of individual responses (SD_IR) is recommended for estimating the magnitude of individual differences in training responsiveness in parallel‐arm exercise randomized controlled trials (RCTs). The purpose of this review article is to discuss potential limitations of parallel‐arm exercise RCTs that may confound/complicate the interpretation of the SD_IR. To provide context for this discussion, we define the sources of variation that contribute to variability in the observed responses to exercise training and review the assumptions that underlie the interpretation of SD_IR as a reflection of true individual differences in training responsiveness. This review also contains two novel analyses: (1) we demonstrate differences in variability in changes in diet and physical activity habits across an intervention period in both exercise and control groups, and (2) we examined participant dropout data from six RCTs and found that significantly (P < 0.001) more participants in control groups (12.8%) dropped out due to dissatisfaction with group assignment compared to exercise groups (3.4%). These novel analyses raise the possibility that the magnitude of within‐subject variability may not be equal between exercise and control groups. Overall, this review highlights that potential limitations of parallel‐arm exercise RCTs can violate the underlying assumptions of the SD_IR and suggests that these limitations should be considered when interpreting the SD_IR as an estimate of true individual differences in training responsiveness.

Triceps Surae Muscle Architecture Adaptations to Eccentric Training

Background

Eccentric exercises have been used in physical training, injury prevention, and rehabilitation programs. The systematic use of eccentric training promotes specific morphological adaptations on skeletal muscles. However, synergistic muscles, such as the triceps surae components, might display different structural adaptations due to differences in architecture, function, and load sharing. Therefore, the purpose of this study was to determine the effects of an eccentric training program on the triceps surae (GM, gastrocnemius medialis; GL, gastrocnemius lateralis; and SO, soleus) muscle architecture.

Methods

Twenty healthy male subjects (26 ± 4 years) underwent a 4-week control period followed by a 12-week eccentric training program. Muscle architecture [fascicle length (FL), pennation angle (PA), and muscle thickness (MT)] of GM, GL, and SO was evaluated every 4 weeks by ultrasonography.

Results

Fascicle lengths (GM: 13.2%; GL: 8.8%; SO: 21%) and MT (GM: 14.9%; GL: 15.3%; SO: 19.1%) increased from pre- to post-training, whereas PAs remained similar. GM and SO FL and MT increased up to the 8th training week, whereas GL FL increased up to the 4th week. SO displayed the highest, and GL the smallest gains in FL post-training.

Conclusion

All three synergistic plantar flexor muscles increased FL and MT with eccentric training. MT increased similarly among the synergistic muscles, while the muscle with the shortest FL at baseline (SO) showed the greatest increase in FL.

CARDIOVASCULAR AND STRENGTH ADAPTATIONS IN CONCURRENT TRAINING IN HYPERTENSIVE WOMEN

ABSTRACT Introduction Physical exercise has been recommended as a non-pharmacological strategy for preventing and controlling hypertension. Objective To verify chronic cardiovascular and muscle strength adaptations in hypertensive women who underwent 12 weeks of concurrent training (CT) in different orders. Methods Twenty hypertensive women were randomly assigned into 2 groups: resistance exercise-endurance group (REE; 56.00 ± 5.20 years; 78.95 ± 8.28 kg; 155.10 ± 5.30 cm; 33.00 ± 5.30 kg.m-2) and endurance-resistance exercise group (ERE; 57.10 ± 13.38 years; 76.56 ± 18.87 kg; 155.50 ± 8.18 cm; 31.41 ± 5.84 kg.m-2). The endurance exercise was composed of 3 sets of 4 exercises, with 8-RM loads with a 90-second break between sets and exercises. The resistance exercise lasted for 25 minutes and was of progressive intensity. Muscle strength (8-RM), systolic and diastolic blood pressure, heart rate, and double product were assessed pre- and post-exercise. Results The ANOVA showed significant increases in strength for all exercises (p <0.0001) regardless of the order of the concurrent training (bench press, p = 0.680; leg press, p = 0.244; seated row, p = 0.668; and leg extension, p = 0.257). No significant differences in systolic (p = 0.074) and diastolic blood pressures (p = 0.064) were observed for different CT conditions. However, significant reductions in systolic (p = 0.0001) and diastolic blood pressures (p = 0.006) and double product (p = 0.006) only occurred in the REE group. Conclusion Endurance training and resistance exercise promote significant muscle strength gains after 12 weeks of training regardless of CT order in hypertensive women. Beneficial cardiovascular responses (SBP, DBP, and RPP) were also observed when endurance training was initiated. Level of evidence I; Therapeutic Studies - Investigating Treatment Outcomes.

Concurrent exercise circuit protocol performed in public fitness facilities meets the American College of Sports Medicine guidelines for energy cost and metabolic intensity among older adults in Rio de Janeiro City

The current study investigated whether a single bout of concurrent exercise (Ex Rx) at Third Age Academies (TAAs) in Rio de Janeiro City meets the American College of Sports Medicine (ACSM) guidelines for energy cost and metabolic intensity in older adults. Nine subjects (5 males and 4 females, 63-80 years of age) visited the laboratory for clinical screening and for anthropometrical, resting, and maximal oxygen uptake assessments. Thereafter, subjects performed an Ex Rx circuit consisting of a single circuit alternating aerobic and resistance exercises with outdoor exercise equipment using body mass as the load (total of 9 exercises, 1-2 sets of 15 repetitions). Expired gases were collected via a metabolic cart during exercise bouts. The mean observed energy cost value of 169.1 kcal was slightly greater than the minimum value of 150 kcal reported in the ACSM guidelines (p = 0.018). Like energy cost, all the intensity markers adopted to analyze the physiological strain induced by the Ex Rx circuit significantly exceeded their reference values for moderate intensity (reference values: 3.2 METs (mean observed value = 4.6 METs, p = 0.002); 40% of oxygen uptake reserve (mean observed value = 51.5%, p = 0.040); 40% of heart rate reserve (mean observed value = 64.1%, p < 0.001)), according to the ACSM guidelines. In conclusion, a single bout of Ex Rx circuit performed at TAAs in Rio de Janeiro City was able to induce a physiological strain (i.e., energy cost and intensity) compatible with ACSM recommendations for eliciting health benefits among older adults.