The Effect of Time-Equated Concurrent Training Programs in Resistance-Trained Men

Chad Dolan; Justin M Quiles; Jacob A Goldsmith; Kristin M Mendez; Alex Klemp; Zac P Robinson; Joshua C Pelland; Catherine Coccia; Michael C Zourdos

doi:10.5114/jhk/185637

The Effect of Time-Equated Concurrent Training Programs in Resistance-Trained Men

J Hum Kinet. 2024 Apr 15;91(Spec Issue):87-103. doi: 10.5114/jhk/185637. eCollection 2024 Mar.

Authors

Chad Dolan¹, Justin M Quiles¹, Jacob A Goldsmith^{2

3}, Kristin M Mendez¹, Alex Klemp¹, Zac P Robinson¹, Joshua C Pelland¹, Catherine Coccia⁴, Michael C Zourdos¹

Affiliations

¹ Muscle Physiology Laboratory, Department of Exercise Science and Health Promotion, Florida Atlantic University, Boca Raton, FL, USA.
² James J. Peters VA Medical Center, Spinal Cord Injury Research, Bronx, NY, USA.
³ Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, USA.
⁴ Department of Dietetics and Nutrition, Florida International University, Miami, FL, USA.

Abstract

The purpose of this investigation was to compare the effects of three different concurrent training (CT) programs and a resistance training (RT) program. Twenty-three resistance trained men (age: 24 ± 3 years) were randomized into four groups: concurrent RT and high intensity interval cycling (CTH, n = 6), concurrent RT and moderate intensity continuous cycling (CTM, n = 5), RT and barbell circuit training (RTC, n = 6), or RT only (RT, n = 6). Back squat and bench press strength, quadriceps, and pectoralis muscle thickness, VO_2peak, and maximum workload (W_max, Watts) were assessed. Squat strength gains were meaningful in all groups and comparable among CTH (16.88 kg [95% CrI: 11.15, 22.63]), CTM (25.54 kg [95% CrI: 19.24, 31.96]), RTC (17.5 kg [95% CrI: 11.66, 23.39]), and RT (20.36 kg [95% CrI: 15.29, 25.33]) groups. Bench press strength gains were meaningful in all groups and comparable among CTH (11.86 kg [95% CrI: 8.28, 15.47]), CTM (10.3 kg [95% CrI: 6.49, 14.13]), RTC (4.84 kg [95% CrI: 1.31, 8.47]), and RT (10.16 kg [95% CrI: 7.02, 13.22]) groups. Quadriceps hypertrophy was meaningful in all groups and comparable among CTH (2.29 mm [95% CrI: 0.84, 3.76]), CTM (3.41 mm [95% CrI: 1.88, 4.91]), RTC (2.6 mm [95% CrI: 1.17, 4.05]), and RT (2.83 mm [95% CrI: 1.55, 4.12]) groups. Pectoralis hypertrophy was meaningful in CTH (2.29 mm [95% CrI: -0.52, 5.1]), CTM (5.14 mm [95% CrI: 2.1, 8.15]), and RTC (7.19 mm [95% CrI: 4.26, 10.02]) groups, but not in the RT group (1 mm [95% CrI: -1.59, 3.59]); further, between-group contrasts indicated less pectoralis growth in the RT compared to the RTC group. Regarding cardiovascular outcomes, only the RTH and RTM groups experienced meaningful improvements in either measure (VO_2peak or W_max). These data suggest that the interference effect on maximal strength and hypertrophy can be avoided when the aerobic training is moderate intensity cycling, high intensity cycling, or a novel barbell circuit for ~one hour per week and on non-RT days. However, the barbell circuit failed to elicit meaningful cardiovascular adaptations.

Keywords: aerobic training; hypertrophy; resistance exercise; strength.