Abstract
Inclusion Body Myositis (IBM) is a rare, progressive inflammatory myopathy characterized by asymmetrical muscle atrophy of the quadriceps and finger flexors, resulting in impaired function and increased fall risk. Although supervised resistance exercise has been shown to be safe in inflammatory myopathies, most prior studies have emphasized low-resistance or non-weighted interventions, with limited focus on quadriceps function, which plays a critical role in sit-to-stand performance and fall prevention. PURPOSE: To determine whether a 12-week progressive overload resistance training program could improve or preserve lower-limb strength, muscle mass, and functional mobility in a patient with IBM. METHODS: One male participant with a confirmed diagnosis of IBM, who had been cleared by his physician, completed an exercise physiologist-led 12-week progressive overload intervention focused on lower-limb function. Three times per week, the participant performed weighted sit-to-stand movements in 2 to 3 sets of 6 to 10 reps, with 3 minutes of rest between sets. Weights were secured to a hip belt, with the load progressing incrementally by ~10-22% of the working weight, as tolerated. Assessments conducted at baseline and post-intervention included DEXA scans, Biodex testing of each quadriceps, Functional Fitness Chair Stand Test (CST), Timed Up-and-Go (TUG), and balance measures. Additionally, functional performance and Biodex testing were conducted at the midpoint of the study. RESULTS: Peak torque extension increased in the right (R) leg from 5.3 ft-lbs pretest to 7.5 ft-lbs posttest (+41.5%) and decreased in the left (L) leg from 20.2 ft-lbs to 16.2 ft-lbs (-24.70%). Peak torque asymmetry decreased from 282% to 115% (-173.0%), and impulse difference decreased from 362.5% to 100% (-262.5%). Coefficient of variation decreased in both legs: R leg, 173.2% to 0% (-173.2%); L leg, 14.3% to 5.1% (-9.2%). Performance in the CST improved from 6.5 stands to 7.5 stands (+15.40%), and TUG test times improved from 18.24 s to 15.10 s. DEXA scans showed improvements of +2.4% and +1.8% in lean mass of the R and L legs, respectively. Balance tests showed vertical loading of the R leg increased 91.22%, vertical unloading of the L leg increased 216.95%, and the center of pressure area of the R leg increased by 888.67%, reflecting altered postural control. CONCLUSION: Progressive overload resistance training produced measurable improvements in motor control and balance, strength symmetry, and mobility in a patient with IBM. Lean mass increases exceeded the standard error of measurement for DEXA, indicating true preservation of lower-limb muscle mass. Findings support the safety of progressive overload resistance training for patients with IBM and its potential to improve neuromuscular efficiency and slow both functional decline and muscular degeneration.
Recommended Citation
Haynes, Cara F.; Nuner, Emery; Dalby, Ashley; and Jeon, Woohyoung
(2026)
"Effects of Progressive Overload Resistance Training on Lower-Limb Strength, Muscle Mass, and Mobility in Inclusion Body Myositis: An N-of-1 Study,"
International Journal of Exercise Science: Conference Proceedings: Vol. 2:
Iss.
18, Article 54.
Available at:
https://digitalcommons.wku.edu/ijesab/vol2/iss18/54