A Pilot 24-Week 'Bulk and Cut' Dietary Protocol Combined with Resistance Training Is Feasible and Improves Body Composition and TNF-α Concentrations in Untrained Adult Males.
Study Goal
The researchers aimed to evaluate the effects of a 24-week bodybuilding program combining resistance training with a dietary bulk-and-cut protocol on body composition, muscle strength, and inflammatory markers in middle-aged males with obesity.
Results Summary
The intervention significantly increased muscle strength (deadlift +46%, squat +65%) and improved body composition (fat-free mass +3%, body fat -6%). It also reduced resting TNF-α concentrations by 15%, indicating reduced inflammation, though other inflammatory markers and lipids did not change significantly.
Population
Middle-aged untrained males with obesity (BMI = 35.0 ± 4.6 kg/m², body fat = 36 ± 5%).
Effective Dosage
Not specified (resistance training combined with 12-week cycles of caloric bulking and cutting).
Duration
24 weeks.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
24-week bodybuilding program combining resistance training (RT) with a dietary bulk-and-cut protocol | increase | muscle strength | middle-aged adult males with obesity | - | led to significant increases | #1 |
24-week bodybuilding program combining resistance training (RT) with a dietary bulk-and-cut protocol | increase | deadlift strength | middle-aged adult males with obesity | +46% | significant increases | #2 |
24-week bodybuilding program combining resistance training (RT) with a dietary bulk-and-cut protocol | increase | squat strength | middle-aged adult males with obesity | +65% | significant increases | #3 |
24-week bodybuilding program combining resistance training (RT) with a dietary bulk-and-cut protocol | increase | fat-free mass | middle-aged adult males with obesity | +3% | Improvements in body composition were characterized by an increase | #4 |
24-week bodybuilding program combining resistance training (RT) with a dietary bulk-and-cut protocol | decrease | body fat percentage | middle-aged adult males with obesity | -6% | Improvements in body composition were characterized by a decrease | #5 |
24-week bodybuilding program combining resistance training (RT) with a dietary bulk-and-cut protocol | no change | circulating lipids (triglycerides, total, low-density, and high-density cholesterol) | middle-aged adult males with obesity | no significant change | did not change significantly | #6 |
24-week bodybuilding program combining resistance training (RT) with a dietary bulk-and-cut protocol | no change | C-reactive protein (CRP) | middle-aged adult males with obesity | no significant change | did not change significantly | #7 |
24-week bodybuilding program combining resistance training (RT) with a dietary bulk-and-cut protocol | no change | interleukin-6 (IL-6) | middle-aged adult males with obesity | no significant change | did not change significantly | #8 |
24-week bodybuilding program combining resistance training (RT) with a dietary bulk-and-cut protocol | no change | interleukin-10 (IL-10) | middle-aged adult males with obesity | no significant change | did not change significantly | #9 |
24-week bodybuilding program combining resistance training (RT) with a dietary bulk-and-cut protocol | decrease | tumor necrosis factor-alpha (TNF-α) | middle-aged adult males with obesity | 15% lower concentrations at week 24 compared to baseline | notable reduction | #10 |
24-week bodybuilding program combining resistance training (RT) with a dietary bulk-and-cut protocol | increase | body composition | middle-aged adult males with obesity | - | leading to improvements | #11 |
24-week bodybuilding program combining resistance training (RT) with a dietary bulk-and-cut protocol | decrease | resting TNF-α concentrations | middle-aged adult males with obesity | - | lower | #12 |
Background/Objectives: This study piloted a 24-week bodybuilding program combining resistance training (RT) with a dietary bulk-and-cut protocol in middle-aged adult males. Methods: Seven untrained males (33 ± 3.0 years; BMI = 35.0 ± 4.6 kg/m2; body fat = 36 ± 5%) completed a 24-week intervention combining RT with a dietary protocol consisting of 12-week cycles of caloric bulking (0-12 weeks) and cutting (12-24 weeks). The participant retention rate was 64%, while compliance with training was 96.7%, and adherence to dietary cycles was over 93%. To assess the preliminary efficacy of the intervention, venous blood samples and measurements of body composition (BodPod), muscle strength, and VO2max (cycle ergometer) were collected at baseline (week 0) and following the bulking (week 12) and cutting (week 24) cycles. Circulating lipids (triglycerides, total, low-density, and high-density cholesterol), C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-10 (IL-10) were measured in serum. Results: The training led to significant increases in muscle strength, especially in the deadlift (+46%, p < 0.001) and squat (+65%, p < 0.001). Improvements in body composition were characterized by an increase in fat-free mass and a decrease in body fat percentage over the 24-week intervention (+3% and -6%, respectively, p < 0.05). Lipids, CRP, IL-6, and IL-10 did not change significantly, but there was a notable reduction in TNF-α (time effect p = 0.05, pη2 = 0.39), with 15% lower concentrations at week 24 compared to baseline, indicating reduced inflammation. Conclusions: Overall, the pilot intervention achieved high compliance and adherence rates, leading to improvements in body composition and lower resting TNF-α concentrations in a group of middle-aged males with obesity.