The effect of fasting on indicators of muscle damage

• Published in: Experimental gerontology Vol. 48; no. 10; pp. 1101 - 1106
• Main Authors: Dannecker, Erin A., Liu, Ying, Rector, R. Scott, Thomas, Tom R., Sayers, Stephen P., Leeuwenburgh, Christiaan, Ray, Bimal K.
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 01.10.2013
• Subjects: Arm - anatomy & histology; Body Height - physiology; Body Weight - physiology; Caloric Restriction - methods; Delayed-onset muscle soreness; Elbow - anatomy & histology; Exercise - physiology; Fasting - physiology; Female; Humans; Inflammation; Interleukin-1beta - metabolism; Intermittent fasting; Male; Muscle damage; Muscle Strength - physiology; Muscle, Skeletal - physiology; Myalgia - prevention & control; Myoglobin - metabolism; Myositis - prevention & control; Nitric Oxide - metabolism; Pain Measurement; Postprandial Period; Sprains and Strains - prevention & control; Stretch injury; Tumor Necrosis Factor-alpha - metabolism; Young Adult; Stretch injury; Inflammation; Delayed-onset muscle soreness; Muscle damage; Intermittent fasting
• ISSN: 0531-5565; 1873-6815
• DOI: 10.1016/j.exger.2012.12.006

Many studies have tested the consumption of foods and supplements to reduce exercise-induced muscle damage, but fasting itself is also worthy of investigation due to reports of beneficial effects of caloric restriction and/or intermittent fasting on inflammation and oxidative stress. This preliminary investigation compared indicators of exercise-induced muscle damage between upper-body untrained participants (N=29, 22yrs old (SD=3.34), 12 women) who completed 8h water-only fasts or ate a controlled diet in the 8h prior to five consecutive laboratory sessions. All sessions were conducted in the afternoon hours (i.e., post meridiem) and the women completed the first session while in the follicular phase of their menstrual cycles. Measures of muscle pain, resting elbow extension, upper arm girth, isometric strength, myoglobin (Mb), total nitric oxide (NO), interleukin 1beta (IL1b), and tumor necrosis factor alpha (TNFa) were collected before and after eccentric contractions of the non-dominant elbow flexors were completed. The fasting group's loss of elbow extension was less than the post-prandial group (p<.05, eta2=.10), but the groups did not change differently across time for any other outcome measures. However, significantly higher NO (p<.05, eta2=.22) and lower TNFa (p<.001, eta2=.53) were detected in the fasting group than the post-prandial group regardless of time. These results suggest intermittent fasting does not robustly inhibit the signs and symptoms of exercise-induced muscle damage, but such fasting may generally affect common indirect markers of muscle damage. ► We tested effects of fasting on exercise-induced muscle damage in humans. ► Daily 8-hour fasts were compared to a controlled meal within 4–5h of visit. ► Indicators of damage were collected before and across five days after exercise. ► The fasts did not robustly protect against exercise-induced muscle damage. ► However, NO was higher and TNFa was lower in the fasting group across time.