Effects of Nonperiodized and Linear Periodized Combined Training on Health-Related Physical Fitness in Adults With Obesity: A Randomized Controlled Trial

Characteristics of interventions with exercise according to the adherence of adults with obesity: A systematic review

The aim was to summarize the characteristics of exercise interventions based on the adherence of adults with obesity. Studies were identified through a systematic review of the literature conducted in databases in June 2022. The articles selected were from clinical trials involving adults with obesity. The total number of prescribed sessions and the mean or percentage of sessions attended by participants who completed the intervention were identified, along with details of the exercise prescription, including duration, attendance, and intensity control. A total of 21 studies were included in the synthesis. The adherence percentage ranged from 18% to 99% of the prescribed exercise sessions. Interventions that provided only guidance meetings for physical activities without supervising the training-allowing participants to choose the modality and loads-resulted in adherence to less than half of the prescribed sessions. The session duration and weekly attendance varied between 30-60 min and 2-3 times per week across the studies synthesized. These variables did not appear to significantly affect adherence percentages in this population. It was possible to conclude that supervised interventions, with combined training, which include moderate to high-intensity physical exercises and/or interval training and with some social support, resulted in greater adherence to sessions in adults with obesity.

Effects of Periodization on Strength and Muscle Hypertrophy in Volume-Equated Resistance Training Programs: A Systematic Review and Meta-analysis

BACKGROUND

In resistance training, periodization is often used in an attempt to promote development of strength and muscle hypertrophy. However, it remains unclear how resistance training variables are most effectively periodized to maximize gains in strength and muscle hypertrophy.

OBJECTIVE

The aims of this study were to examine the current body of literature to determine whether there is an effect of periodization of training volume and intensity on maximal strength and muscle hypertrophy, and, if so, to determine how these variables are more effectively periodized to promote increases in strength and muscle hypertrophy, when volume is equated between conditions from pre to post intervention.

METHODS

Systematic searches were conducted in PubMed, Scopus and SPORTDiscus databases. Data from the individual studies were extracted and coded. Meta-analyses using the inverse-variance random effects model were performed to compare 1-repetition maximum (1RM) and muscle hypertrophy outcomes in (a) non-periodized (NP) versus periodized training and (b) in linear periodization (LP) versus undulating periodization (UP). Subgroup analyses examining whether results were affected by training status were performed. Meta-analyses of other periodization model comparisons were not performed, due to a low number of studies.

RESULTS

Thirty-five studies met the inclusion criteria. Results of the meta-analyses comparing NP and periodized training demonstrated an overall effect on 1RM strength favoring periodized training (ES 0.31, 95% confidence interval (CI) [0.04, 0.57]; Z = 2.28, P = 0.02). In contrast, muscle hypertrophy did not differ between NP and periodized training (ES 0.13, 95% CI [-0.10, 0.36]; Z = 1.10, P = 0.27). Results of the meta-analyses comparing LP and UP indicated an overall effect on 1RM favoring UP (ES 0.31, 95% CI [0.02, 0.61]; Z = 2.06, P = 0.04). Subgroup analyses indicated an effect on 1RM favoring UP in trained participants (ES 0.61, 95% CI [0.00, 1.22]; Z = 1.97 (P = 0.05)), whereas changes in 1RM did not differ between LP and UP in untrained participants (ES 0.06, 95% CI [-0.20, 0.31]; Z = 0.43 (P = 0.67)). The meta-analyses showed that muscle hypertrophy did not differ between LP and UP (ES 0.05, 95% CI [-0.20, 0.29]; Z = 0.36 (P = 0.72)).

CONCLUSION

The results suggest that when volume is equated between conditions, periodized resistance training has a greater effect on 1RM strength compared to NP resistance training. Also, UP resulted in greater increases in 1RM compared to LP. However, subgroup analyses revealed that this was only the case for trained and not previously untrained individuals, indicating that trained individuals benefit from daily or weekly undulations in volume and intensity, when the aim is maximal strength. Periodization of volume and intensity does not seem to affect muscle hypertrophy in volume-equated pre-post designs. Based on this, we propose that the effects of periodization on maximal strength may instead be related to the neurophysiological adaptations accompanying resistance training.

Effects of Non-periodized and Linear Periodized Combined Exercise Training on Insulin Resistance Indicators in Adults with Obesity: A Randomized Controlled Trial

BACKGROUND

The aim was to verify the effect of non-periodized and linear periodized combined (aerobic plus resistance) exercise training on insulin resistance markers in adults with obesity.

METHODS

A blinded randomized control trial was conducted with three groups of individuals with obesity (BMI, 30-39.9 kg/m²): control group (CG, n = 23), non-periodized group (NG, n = 23), and linear periodized group (PG, n = 23). The NG and PG performed aerobic and resistance exercises in the same session in aerobic-resistance order for 16 weeks. Both intervention groups trained three sessions weekly, with a total duration of 60 min each. The aerobic training of the NG had a duration of 30 min always between 50% and 59% of the reserve heart rate (HRres), while resistance exercise was comprised of 6 exercises, performed always in 2 × 10-12 maximum repetitions (MRs). The PG progressed the aerobic and resistance training from 40%-49% to 60%-69% (HRres) and from 2 × 12-14 to 2 × 8-10 RM, respectively, along the intervention period. The evaluated indicators of insulin resistance included fasting glucose, fasting insulin, and homeostasis model assessment-estimated insulin resistance (HOMA-IR) collected pre- and post-intervention. The analyses to verify the exercise training effect were performed using generalized estimating equations.

RESULTS

After 16 weeks of training, per protocol analysis (n = 39) showed significant reductions in HOMA-IR only in the training groups (NG: Δ = - 1.6, PG: Δ = - 0.6; p = 0.094). Intention-to-treat analysis demonstrated significant reductions in fasting insulin levels (NG: Δ = - 1.4, PG: Δ = - 1.0; p = 0.004) and HOMA-IR (NG: Δ = - 5.5, PG: Δ = - 3.8; p = 0.002).

CONCLUSION

Periodized and non-periodized combined exercise training similarly reduces insulin resistance markers in adults with obesity.

TRIAL REGISTRATION

Brazilian Registry of Clinical Trials, RBR-3c7rt3. Registered 07 February 2019- https://ensaiosclinicos.gov.br/trial/5970/1 .