Effects of Exercise Type on Muscle Strength and Body Composition in Men and Women: A Systematic Review and Meta-Analysis

Background and Objectives: There are typical differences in body composition and distribution of muscle fiber types between women and men. However, research investigating the effects of exercise based on sex differences is limited, and studies examining sex differences in physiological adaptations according to exercise type are scarce. We aimed to compare the effects of exercise types on muscle strength and body composition in men and women through a meta-analysis. Materials and Methods: A systematic literature search was conducted using the PubMed/Medline, Web of Science, CINAHL, and EBSCO databases. Keywords included "endurance training", "resistance training", "concurrent training", "muscle strength", "body composition", "sex characteristics", and "men and women". The standardized mean difference (SMD) was presented separately for men and women based on the pre- and post-intervention values for each exercise type. Results: Concurrent training showed the greatest effect on the increase in leg press muscle strength in men, and resistance training showed the greatest effect in women. Concurrent training showed the greatest effect size in both men and women in increasing bench press muscle strength. Resistance training and concurrent training showed a small effect size on lean mass reduction in both men and women. Endurance training and concurrent training significantly reduced fat mass in men. However, no significant changes in fat mass were observed in any exercise type among women. Conclusions: Concurrent training is the most efficient type of exercise for men, as it is effective in increasing upper- and lower-body muscle strength, increasing lean mass, and reducing fat mass. Resistance training is most effective in increasing muscle strength in females, whereas endurance training is most effective in reducing fat mass. However, it is difficult to corroborate these results because of the lack of study samples included in the analysis and the differences in exercise methods, participant age, and exercise duration.

Two-week step-reduction has limited negative effects on physical function and metabolic health in older adults

PURPOSE

This study determined the effects of a 2-week step-reduction period followed by 4-week exercise rehabilitation on physical function, body composition, and metabolic health in 70-80-year-olds asymptomatic for injury/illness.

METHODS

A parallel-group randomized controlled trial (ENDURE-study, NCT04997447) was used, where 66 older adults (79% female) were randomized to either intervention or control group. The intervention group reduced daily steps to < 2000, monitored by accelerometer, for two weeks (Period I) and then step-reduction requirement was removed with an additional exercise rehabilitation 4 times per week for 4 weeks (Period II). The control group continued their habitual physical activity throughout with no additional exercise intervention. Laboratory tests were performed at baseline, after Period I and Period II. The primary outcome measure was leg lean mass (LLM). Secondary outcomes included total lean and fat mass, blood glucose and insulin concentration, LDL cholesterol and HDL cholesterol concentration, maximal isometric leg press force (MVC), and chair rise and stair climb performance.

RESULTS

LLM remained unchanged in both groups and no changes occurred in physical function nor body composition in the intervention group in Period I. HDL cholesterol concentration reduced after Period I (from 1.62 ± 0.37 to 1.55 ± 0.36 mmol·L-1, P = 0.017) and returned to baseline after Period II (1.66 ± 0.38 mmol·L-1) in the intervention group (Time × Group interaction: P = 0.065). MVC improved after Period II only (Time × Group interaction: P = 0.009, Δ% = 15%, P < 0.001).

CONCLUSION

Short-term step-reduction in healthy older adults may not be as detrimental to health or physical function as currently thought.

Effect of resistance training on inflammatory markers in middle-aged and older adults: A meta-analysis

BACKGROUND AND OBJECTIVE

A meta-analysis was conducted to evaluate the impact of resistance training on pro-inflammatory cytokines c-reactive protein (CRP), interleukin 6 (IL 6), and tumor necrosis factor- α (TNF- α) in middle-aged and elderly individuals.

METHODS

The retrieval period for the Web of Science and other large electronic databases is set by default to March 2022. Both included and excluded researchers are independent examination literature on the impact of resistance exercise on markers of inflammation in the elderly. The physical medical care Evidence Database scale (Physical Therapy Evidence Database, PEDro) was used to evaluate the research quality, and Revmen 5.3 was used to end the index analysis.

RESULTS

After a total of four rounds of elimination, 12 items were eventually included. The total sample size for the research was 388 persons. Resistance training substantially reduced CRP levels in middle-aged and older individuals, with SMD = -0.56 and 95 % confidence interval ([-0.78, -0.34], P < 0.00001, correspondingly. Resistance training can successfully lower IL6 concentrations in middle-aged and older adults, although the combined impact is not substantial. SMD = -0.25, 95 % CI [-0.54, 0.04]; P = 0.09. TNF- concentrations did not alter significantly following resistance exercise in middle-aged and older adults. The overall effect was SMD = -0.07, with a 95 % confidence interval [-0.37, 0.23], while P = 0.64.

CONCLUSION

Resistance training reduces CRP, IL6, and TNF-α levels among middle-aged and elderly people. However, it has no significant anti-inflammatory effects on TNF-α. Resistance exercise at a moderate level for 3 times / week with a duration of 6-12 weeks or 16-32 weeks, significantly reduced CRP levels. This work contributing to exploring the resistance training program for the elderly to reduce inflammatory markers, and further, providing suggestions for the elderly to participate in resistance training and reduce the concentration of inflammatory markers.

Perspectives on Concurrent Strength and Endurance Training in Healthy Adult Females: A Systematic Review

BACKGROUND

Both strength and endurance training are included in global exercise recommendations and are the main components of training programs for competitive sports. While an abundance of research has been published regarding concurrent strength and endurance training, only a small portion of this research has been conducted in females or has addressed their unique physiological circumstances (e.g., hormonal profiles related to menstrual cycle phase, menstrual dysfunction, and hormonal contraceptive use), which may influence training responses and adaptations.

OBJECTIVE

The aim was to complete a systematic review of the scientific literature regarding training adaptations following concurrent strength and endurance training in apparently healthy adult females.

METHODS

A systematic electronic search for articles was performed in July 2021 and again in December 2022 using PubMed and Medline. This review followed, where applicable, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality of the included studies was assessed using a modified Downs and Black checklist. Inclusion criteria were (1) fully published peer-reviewed publications; (2) study published in English; (3) participants were healthy normal weight or overweight females of reproductive age (mean age between > 18 and < 50) or presented as a group (n > 5) in studies including both females and males and where female results were reported separately; (4) participants were randomly assigned to intervention groups, when warranted, and the study included measures of maximal strength and endurance performance; and (5) the duration of the intervention was ≥ 8 weeks to ensure a meaningful training duration.

RESULTS

Fourteen studies met the inclusion criteria (seven combined strength training with running, four with cycling, and three with rowing or cross-country skiing). These studies indicated that concurrent strength and endurance training generally increases parameters associated with strength and endurance performance in female participants, while several other health benefits such as, e.g., improved body composition and blood lipid profile were reported in individual studies. The presence of an "interference effect" in females could not be assessed from the included studies as this was not the focus of any included research and single-mode training groups were not always included alongside concurrent training groups. Importantly, the influence of concurrent training on fast-force production was limited, while the unique circumstances affecting females were not considered/reported in most studies. Overall study quality was low to moderate.

CONCLUSION

Concurrent strength and endurance training appears to be beneficial in increasing strength and endurance capacity in females; however, multiple research paradigms must be explored to better understand the influence of concurrent training modalities in females. Future research should explore the influence of concurrent strength and endurance training on fast-force production, the possible presence of an "interference effect" in athletic populations, and the influence of unique circumstances, such as hormone profile, on training responses and adaptations.

Effects of concurrent training sequence on VO2max and lower limb strength performance: A systematic review and meta-analysis

The aim of this study is to compare the effects of concurrent strength and endurance training sequences on VO_2max and lower limb strength performance to provide scientific guidance for training practice. We searched PubMed, EBSCO, Web of Science (WOS), Wanfang, and China National Knowledge Infrastructure (CNKI) databases up to December 2022. The included articles were randomized controlled trials that allowed us to compare the strength-endurance (S-E) sequence and endurance-strength (E-S) sequence on VO_2max, maximum knee extension strength, maximum knee flexion strength, and lower limb power. The Cochrane bias risk tool was used to evaluate the methodological quality of the included literature, and Stata 12.0 was used for the heterogeneity test, subgroup analysis, draw forest map, sensitivity analysis, and publication bias evaluation. The results have been presented as standardized mean differences (SMDs) between treatments with 95% confidence intervals and calculations performed using random effects models. Significance was accepted when p < 0.05. The studies included 19 randomized controlled trials (285 males and 197 females), 242 subjects in S-E sequence, and 240 subjects in E-S sequence in the analyses. No difference changes between S-E and E-S sequences has been observed on VO_2max in the overall analysis (SMD = 0.02, 95% CI: -0.21-0.25, p = 0.859). The S-E sequence shows a greater increase in lower limb strength performance than does the E-S sequence (SMD = 0.19, 95% CI: 0.02-0.37, p = 0.032), which was manifested in the elderly (p = 0.039) and women (p = 0.017); in training periods >8 weeks (p = 0.002) and training frequencies twice a week (p = 0.003); and with maximum knee flexion (p = 0.040) and knee extension strength (p = 0.026), while no difference was found in lower limb power (p = 0.523). In conclusion, the effect of VO_2max will not change with different concurrent training sequences. The S-E sequence improves lower limb strength more significantly, mainly in the improvement of knee flexion and knee extension. This advantage is more related to factors such as age, gender, training period, and training frequency.

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.

Changes in Body Composition and Strength after 12 Weeks of High-Intensity Functional Training with Two Different Loads in Physically Active Men and Women: A Randomized Controlled Study

This study examined the effects of two different resistance loads during high-intensity Functional Training (HIFT) on body composition and maximal strength. Thirty-one healthy young individuals were randomly assigned into three groups: moderate load (ML: 70% 1-RM), low load-(LL: 30% 1-RM), and control (CON). Each experimental group performed HIFT three times per week for 12 weeks with a similar total volume load. Body fat decreased equally in both experimental groups after 6 weeks of training (p < 0.001), but at the end of training it further decreased only in LL compared to ML (−3.19 ± 1.59 vs. −1.64 ± 1.44 kg, p < 0.001), with no change in CON (0.29 ± 1.08 kg, p = 0.998). Lean body mass (LBM) increased after 6 weeks of training (p = 0.019) in ML only, while after 12 weeks a similar increase was observed in LL and ML (1.11 ± 0.65 vs. ML: 1.25 ± 1.59 kg, p = 0.034 and 0.013, respectively), with no change in CON (0.34 ± 0.67 kg, p = 0.991). Maximal strength increased similarly in four out of five exercises for both experimental groups by between 9.5% and 16.9% (p < 0.01) at the end of training, with no change in CON (−0.6 to 4.9%, p > 0.465). In conclusion, twelve weeks of HIFT training with either low or moderate resistance and equal volume load resulted in an equal increase in LBM and maximal strength, but different fat loss.

Periodization and Block Periodization in Sports: Emphasis on Strength-Power Training-A Provocative and Challenging Narrative

ABSTRACT

Stone, MH, Hornsby, WG, Haff, GG, Fry, AC, Suarez, DG, Liu, J, Gonzalez-Rave, JM, and Pierce, KC. Periodization and block periodization in sports: emphasis on strength-power training-a provocative and challenging narrative. J Strength Cond Res 35(8): 2351-2371, 2021-Periodization can be defined as a logical sequential, phasic method of manipulating fitness and recovery phases to increase the potential for achieving specific performance goals while minimizing the potential for nonfunctional over-reaching, overtraining, and injury. Periodization deals with the micromanagement of timelines and fitness phases and is cyclic in nature. On the other hand, programming deals with the micromanagement of the training process and deals with exercise selection, volume, intensity, etc. Evidence indicates that a periodized training process coupled with appropriate programming can produce superior athletic enhancement compared with nonperiodized process. There are 2 models of periodization, traditional and block. Traditional can take different forms (i.e., reverse). Block periodization has 2 subtypes, single goal or factor (individual sports) and multiple goals or factors (team sports). Both models have strengths and weaknesses but can be "tailored" through creative programming to produce excellent results for specific sports.

A 10-Week Block of Combined High-Intensity Endurance and Strength Training Produced Similar Changes in Dynamic Strength, Body Composition, and Serum Hormones in Women and Men

Purpose: To examine the potential sex differences in adaptations to combined endurance and strength training in recreationally endurance trained (eumenorrheic) women (n = 9) and men (n = 10).

Methods: Isometric (ISOM_max) and dynamic bilateral leg press (1RM), countermovement jump (CMJ), running performance (3,000 m time trial), lean mass and body fat % (LEAN and FAT% determined by dual X-ray absorptiometry) as well as serum testosterone and cortisol (TES and COR, respectively, measured using hormone-specific immunoassay kits) were examined before a control period and pre, mid, and post a supervised 10-week combined high-intensity interval endurance training (4 × 4 min intervals and 3 × 3 × 100 m repeated sprints) and mixed maximal and explosive strength training. No more than 2 weeks separated training and testing for either women or men and all women were tested in the early follicular phase of the menstrual cycle to minimize the possible influence of menstrual cycle phase on performance measures.

Results: Absolute and relative changes in 1RM, CMJ, 3,000 m, LEAN, and FAT% were similar between groups. The only statistically significant differences observed between groups were observed at post and included a larger Δ% increase in ISOM_max force in men and a relatively greater Δ% decrease in serum TES in women.

Conclusion: Women and men can achieve similar relative adaptations in dynamic maximal strength and CMJ as well as endurance performance gains and body composition over the same high-intensity 10-week combined program, although relative adaptations in TES may differ.

Health-Related Physical Fitness Benefits in Sedentary Women Employees after an Exercise Intervention with Zumba Fitness®

Background: The protective properties of high physical fitness levels on health are manifest independently of age, sex, fatness, smoking, alcohol consumption, and other clinical factors. However, women are less active than men, which contributes to low physical fitness and a high risk of CVD. Thus, the objective of this study is to analyze the effect of two exercise interventions on health-related physical fitness in sedentary employed females. Methods: A total of 98 physically inactive adult women were randomly assigned to 3 study groups: the control group (CG) = 31, the endurance training group based on Zumba Fitness^® classes (ET; n = 39), and the concurrent training group that had an extra muscle-strengthening workout after the Zumba Fitness^® class (CnT; n = 28). Body composition (BMI, waist circumference), motor fitness (one-leg stand test), musculoskeletal fitness (shoulder–neck mobility, handgrip strength test, jump and reach test, and dynamic sit-up test), and cardiorespiratory fitness (2-km test and estimated VO₂ max) were assessed with the ALPHA-Fit test battery for adults. Results: Both interventions showed a significant improvement in the majority of health-related fitness and body composition variables/test (waist circumference: ET = −2.275 ± 0.95, p = 0.02, CnT = −2.550 ± 1.13, p = 0.03; one-stand leg test: ET = 13.532 ± 2.65, p < 0.001; CnT = 11.656 ± 2.88, p < 0.001; shoulder–neck mobility: ET = 1.757 ± 0.44, p < 0.001, CnT = 2.123 ± 0.47, p < 0.001; handgrip test: 0.274 ± 0.08, p < 0.001, CnT = 0.352 ± 0.08, p < 0.001; dynamic sit-up: ET = 1.769 ± 0.45, p < 0.001, CnT = −1.836 ± 0.49, p < 0.001; 2-km test time: −1.280 ± 0.25, p < 0.001, CnT = −1.808 ± 0.28, p < 0.001; estimated VO₂ max: ET = 1.306 ± 0.13, p < 0.001, CnT = 1.191 ± 0.15, p < 0.001). There were no significant differences after the intervention between the two exercise intervention groups. Conclusions: Exercise interventions based on Zumba fitness^® or Zumba fitness^® combined with an extra muscle-strengthening workout based on bodyweight training exercises are effective strategies to improve the health-related physical fitness in sedentary women employees.

Effect of Two Choreographed Fitness Group-Workouts on the Body Composition, Cardiovascular and Metabolic Health of Sedentary Female Workers

Daily sedentary working hours contribute negatively to body composition, cardiovascular and metabolic health, especially in women, who are usually less active than men. The objective of this study was to analyze the effect of two trending choreographed fitness group-workouts on the body composition and cardiovascular and metabolic health of sedentary female workers. A total of 98 physically inactive and working women (38.9 ± 6.4 years of age) were randomly assigned to three study groups: Control group (CG) = 31, Zumba Fitness^® with three one-hour classes per week (ZF) = 39, and Zumba Fitness with 20 min of additional Bodyweight strength training (ZF + BW) = 28. Measurements included body composition, blood pressure, cardiovascular risk by the Framingham Heart Study tools (10 yr cardiovascular risk and vascular age) and a metabolic blood panel. Post-intervention, both choreographed fitness group-workouts reached a similar significant loss of fat mass (ZF = 2.805 ± 0.48, p < 0.0001; ZF + BW = 3.540 ± 0.04, p < 0.0001), an increase in muscle mass (ZF = 1.70 ± 0.581, p = 0.005; ZF + BW = 3.237 ± 0.657, p < 0.0001) and a decrease in SBP (ZF= 6.454 ± 1.70, p < 0.0001; ZF + BW = 4.12 ± 1.95, p = 0.039). Only the ZF group significantly improved the 10 yr cardiovascular risk (p = 0.032) and metabolic age (p = 0.0025) post-intervention. No significant improvement was observed in the metabolic panel for both choreographed fitness group-workouts. In conclusion, the ZF program generated improvements in cardiovascular and metabolic risk variables compared to ZF + BW or CG. Both choreographed fitness group-workouts contributed similarly to the improvement in systolic blood pressure, fat mass, muscle mass, and also engendered a great adherence to exercise.

Changes in inflammation markers after a 10-week high-intensity combined strength and endurance training block in women: The effect of hormonal contraceptive use

OBJECTIVES

The influence of hormonal contraceptives (HC) on inflammation and body composition after high-intensity combined strength and endurance training was investigated.

DESIGN

Active healthy women formed two training groups: HC users (HCU, n = 9) and those who had never used HC (NHC, n = 9). Training included two strength training sessions and two high-intensity interval training sessions per week for 10 weeks.

METHODS

Before (PRE) and after (POST) the training intervention, high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1beta (IL-1β) concentrations were measured. Dual-energy X-ray absorptiometry was used to estimate fat mass (FM), abdominal fat mass (aFM), and lean mass (LM).

RESULTS

Circulating concentrations of hs-CRP decreased significantly in the NHC from pre to post with -0.46 mg l^-1 (95% CI: -0.78, -0.14, p = 0.009, ES = 0.434), whereas a significant increase was observed in HCU from pre to post with 0.89 mg l^-1 (95% CI: 1.66, 0.12, p = 0.048, ES = 1.988) with a significant between-group difference (p = 0.015). In addition, hs-CRP concentration was significantly higher in HCU than in NHC after training (p = 0.036) at post. Lean mass increased significantly more in NHC than in HCU (p = 0.049).

CONCLUSIONS

High-intensity combined strength and endurance training can modify inflammation and body composition of women. The present study showed that inflammation, in terms of hs-CRP was higher post training in HCU than NHC, which may be associated with smaller gains in lean mass in response to training.

Changes in Physical Fitness After 12 Weeks of Structured Concurrent Exercise Training, High Intensity Interval Training, or Whole-Body Electromyostimulation Training in Sedentary Middle-Aged Adults: A Randomized Controlled Trial

This study aimed to investigate the influence of different exercise training modalities [(i) a concurrent training based on physical activity recommendation from the World Health Organization group (PAR group), (ii) a high intensity interval training group (HIIT group), and (iii) a high intensity interval training adding whole-body electromyostimulation group (WB-EMS group)] on physical fitness in sedentary middle-aged adults. A total of 89 (52.7% women) middle-aged sedentary adults (53.7 ± 5.1 years old) were enrolled in the FIT-AGING study. Cardiorespiratory fitness was determined by a maximum treadmill test using indirect calorimetry. Lower, upper, and core body muscular strength were assessed by an isokinetic strength test, by the handgrip strength test, and by several core strength endurance tests, respectively. All the exercise types induced similar increases on cardiorespiratory fitness (Δ VO₂max ≥ 11%, Δ maximal heart rate ≥ 8%, and Δ total test duration ≥ 14%; all P ≤ 0.034), as well as on muscular strength (Δ extension and flexion peak torque ≥ 10%, Δ total hand grip ≥ 3%, Δ core strength endurance tests ≥ 20%; all P ≤ 0.050) compared with a control group. In conclusion, our results suggest that a 12-week structured exercise intervention improves physical fitness regardless of the training program in sedentary middle-aged adults. Despite slightly greater improvements in some physical fitness variables, the changes observed in the WB-EMS group were not superior to the other exercise programs.

Effects of morning vs. evening combined strength and endurance training on physical performance, sleep and well-being

The aim of the present study was to examine how combined strength and endurance training in the morning and evening influences the adaptations in strength and endurance performance, perception of time management, psychological well-being and sleep. The combined training period lasted for 24 weeks and the participants were divided into the morning training (MG, n = 18), evening training (EG, n = 24) and control groups (CG, n = 10). Isometric leg press force (iLP), maximal oxygen consumption (VO₂max), sleep behavior, fatigue, time management, motivation, self-esteem and health-related quality of life (HRQoL) were assessed. Morning to evening difference in iLP was observed in both MG and EG at Pre and Post, with higher force values in the evening, but not for VO₂max. iLP force increased significantly in EG in the morning (p < 0.001) and evening (p = 0.010). VO₂max increased in MG and EG both in the morning (both p < 0.001) and in the evening (MG: p < 0.001; EG: p = 0.003). Participants of the present study slept 7-8 h per night and the self-reported sleep duration, get-up time and the average time to go to bed were similar between the groups and did not change from Pre to Post. From HRQoL dimensions, the score for bodily pain decreased in MG (p = 0.029) and significant between-group differences were observed for Pre-Post changes in MG and EG (p = 0.001) as well as between MG and CG (p < 0.001). In vitality, a significant between-group difference was observed for Pre to Post changes in MG and EG (p = 0.014). Perception of time management decreased in EG (p = 0.042) but stayed unchanged for MG and CG. For the intrinsic motivation to participate, significant between-group differences were observed for MG and EG (p = 0.033) and between MG and CG (p = 0.032) for Pre to Post changes. Self-esteem improved in MG (p = 0.029) and EG (p = 0.024). The present combined strength and endurance training program performed in the morning and in the evening led to similar improvements in strength and endurance performance. Training in the morning or in the evening did not disrupt the already good sleep behavior and it was able to further increase the self-esteem. Although training in the morning hours may leave more time for free time activities or social life (i.e. family and friends) compared to the evening training, it might be more challenging to stay motivated to participate in prolonged training programs in the morning hours.

Strength Training Improves Metabolic Health Markers in Older Individual Regardless of Training Frequency

The main purpose of the present study was to investigate the effect of frequency, thereby increasing training volume, of resistance training on body composition, inflammation markers, lipid and glycemic profile in healthy older individuals (age range 65–75 year). Ninety-two healthy participants were randomly assigned to one of four groups; performing strength training one- (EX1), two- (EX2), or three- (EX3) times-per-week and a non-training control (CON) group. Whole-body strength training was performed using 2–5 sets and 4–12 repetitions per exercise and 7–9 exercises per session. All training groups attended supervised resistance training for 6 months. Body composition was measured by dual X-ray absorptiometry and fasting blood samples were taken pre- and post-training. There were significant main effects of time for total fat mass (F = 28.12, P < 0.001) and abdominal fat mass (F = 20.72, P < 0.001). Pre- to post-study, statistically significant reductions in fat mass (Δ = -1.3 ± 1.4 kg, P < 0.001, n = 26) were observed in EX3. Pre- to post-study reductions in low density lipoprotein (LDL) concentration (Δ = -0.38 ± 0.44 mmol⋅L^-1, P = 0.003, n = 19) were observed only in EX3, whereas a significant pre- to post-study increases in high density lipoprotein (HDL) concentration (0.14–0.19 mmol⋅L^-1) were observed in all training groups. Most variables at baseline demonstrated a significant (negative) relationship when correlating baseline values with their change during the study including: Interleukin-6 (IL-6) (r = -0.583, P < 0.001), high-sensitivity c-reactive protein (hs-CRP) (r = -0.471, P < 0.001, and systolic blood pressure (r = -0.402, P = 0.003). The present study suggests that having more than two resistance training sessions in a week could be of benefit in the management of body composition and lipid profile. Nevertheless, interestingly, and importantly, those individuals with a higher baseline in systolic blood pressure, IL-6 and hs-CRP derived greatest benefit from the resistance training intervention, regardless of how many times-a-week they trained. Finally, the present study found no evidence that higher training frequency would induce greater benefit regarding inflammation markers or glycemic profile in healthy older adults.

Effect of two different intensity distribution training programmes on aerobic and body composition variables in ultra-endurance runners

The aim of this study was to compare the effects of two different intensity distribution training programmes (polarized (POL) and threshold (THR)) on aerobic performance, strength and body composition variables in ultra-endurance runners. Twenty recreationally trained athletes were allocated to POL (n = 11; age: 40.6 ± 9.7 years; height: 175.4 ± 7 cm; weight: 73.5 ± 10.8 kg; fat mass 18.4 ± 6.0%; VO₂max: 55.8 ± 4.9 ml/kg/min) or THR group (n = 9; age: 36.8 ± 9.2 years; height: 178.5 ± 4.2 cm; weight: 75.5 ± 10.4 kg; fat mass 14.9 ± 5.3%; VO₂max: 57.1 ± 5.2 ml/kg/min) and performed the 12 weeks training programme. Both programmes had similar total time and load but a different intensity distribution (POL = 79.8 ± 2.1% in Zone 1; 3.9 ± 1.9% in Zone 2; 16.4 ± 1.5% in Zone 3; THR = 67.2 ± 4.6% in Zone 1; 33.8 ± 4.6% in Zone 2; 0% in Zone 3). Body composition, isokinetic strength and aerobic running performance were measured before and after each programme. Both groups decreased fat mass after training (POL= Δ-11.2%; p = .017; ES = 0.32; THR= Δ-18.8%; p < .01; ES = 0.48). Also, POL group improved running economy at 10 km/h (Δ-5.4%; p = 0.003; ES = 0.71) and 12 km/h (Δ-4.5%; p = .026; ES = 0.73) and running time to exhaustion (Δ2.4%; p = .011; ES = 0.33). No changes were observed in strength and no significant differences were observed between the group in any variable. Compared with THR distribution, 12 weeks of POL training efficiently improves aerobic performance in recreational ultra-endurance runners.

Effects of Combined Strength and Endurance Training on Physical Performance and Biomarkers of Healthy Young Women

Kyröläinen, H, Hackney, AC, Salminen, R, Repola, J, Häkkinen, K, and Haimi, J. Effects of combined strength and endurance training on physical performance and biomarkers of healthy young women. J Strength Cond Res 32(6): 1554-1561, 2018-Cardiovascular fitness has decreased and obesity has increased in young adults worldwide during the last 10 years. Therefore, there is an urgent need to find out optimal exercise training programs for improving physical performance and health outcomes, especially among sedentary women. Subjects were 25- to 30-year-old women with a very low physical activity, and 65% of them were overweight (body mass index > 25). They performed endurance and strength training 3 times a week for 9 weeks. Independent strength training and instructed endurance training by indoor cycling were prescribed. Measurements were performed before, in the middle, and after the training period. No nutritional guidelines were given to the subjects. The 9-week training period led to an 8.5% increase in estimated maximal oxygen uptake. Maximal isometric strength of the leg and arm extensors as well as trunk flexors and extensors increased by 28.9, 7.8, 27.2, and 16.1%, respectively. Total cholesterol values lowered by 7.6%, and high-density lipoprotein increased by 8.8%, whereas low-density lipoprotein, hemoglobin, serum glucose, and triglyceride remained unchanged. Serum cortisol increased by 22.7%, but no changes in plasma testosterone, estradiol, or sex hormone binding globulin were observed. The skeletal muscle mass increased by 0.8% without other changes in body composition. Our results indicated that only 27 combined endurance and strength training sessions in 9 weeks improved maximal endurance and strength capacity as well as some health outcomes. Thus, combined strength and endurance training itself can induce significant health benefits without the necessity of changes in dietary habits.

The categorization of amateur cyclists as research participants: findings from an observational study

Sampling bias is an issue for research involving cyclists. The heterogeneity of cyclist populations, on the basis of skill level and riding purpose, can generate incorrect inferences about one specific segment of the population of interest. In addition, a more accurate categorization would be helpful when physiological parameters are not available. This study proposes using self-reported data to categorize amateur cyclist types by varying skill levels and riding purposes, therefore improving sample selection in experimental studies. A total of 986 cyclists completed an online questionnaire between February and October 2016. Two-step cluster analyses were performed to generate distinct groups, and dependent variables of these groups were compared (demographics and characteristics of cycling practice). The cluster analysis relied on 4 descriptors (cycling weekly volume, average cycling speed, riding purpose, and cycling discipline) and yielded five distinct groups: competitive road, recreational road, competitive mountain bike (MTB), recreational MTB and competitive triathlon. Among these groups, averages and distributions for age, height, body mass, body mass index, training volume and intensity, and years of experience varied. This categorization can potentially help researchers recruit specific groups of cyclists based upon self-reported data and therefore better align the sample characteristic with the research aims.