Trappe TA, Carroll CC, Dickinson JM, LeMoine JK, Haus JM, Sullivan BE, Lee JD, Jemiolo B, Weinheimer EM, Hollon CJ. Influence of acetaminophen and ibuprofen on skeletal muscle adaptations to resistance exercise in older adults. Am J Physiol Regul Integr Comp Physiol 300: R655-R662, 2011. First published December 15, 2010; doi:10.1152/ajpregu.00611.2010.-Evidence suggests that consumption of over-the-counter cyclooxygenase (COX) inhibitors may interfere with the positive effects that resistance exercise training has on reversing sarcopenia in older adults. This study examined the influence of acetaminophen or ibuprofen consumption on muscle mass and strength during 12 wk of knee extensor progressive resistance exercise training in older adults. Thirty-six individuals were randomly assigned to one of three groups and consumed the COX-inhibiting drugs in double-blind placebo-controlled fashion: placebo (67 Ϯ 2 yr; n ϭ 12), acetaminophen (64 Ϯ 1 yr; n ϭ 11; 4 g/day), and ibuprofen (64 Ϯ 1 yr; n ϭ 13; 1.2 g/day). Compliance with the resistance training program (100%) and drug consumption (via digital video observation, 94%), and resistance training intensity were similar (P Ͼ 0.05) for all three groups. Drug consumption unexpectedly increased muscle volume (acetaminophen: 109 Ϯ 14 cm 3 , 12.5%; ibuprofen: 84 Ϯ 10 cm 3 , 10.9%) and muscle strength (acetaminophen: 19 Ϯ 2 kg; ibuprofen: 19 Ϯ 2 kg) to a greater extent (P Ͻ 0.05) than placebo (muscle volume: 69 Ϯ 12 cm 3 , 8.6%; muscle strength: 15 Ϯ 2 kg), when controlling for initial muscle size and strength. Follow-up analysis of muscle biopsies taken from the vastus lateralis before and after training showed muscle protein content, muscle water content, and myosin heavy chain distribution were not influenced (P Ͼ 0.05) by drug consumption. Similarly, muscle content of the two known enzymes potentially targeted by the drugs, COX-1 and -2, was not influenced (P Ͼ 0.05) by drug consumption, although resistance training did result in a drug-independent increase in COX-1 (32 Ϯ 8%; P Ͻ 0.05). Drug consumption did not influence the size of the nonresistance-trained hamstring muscles (P Ͼ 0.05). Over-thecounter doses of acetaminophen or ibuprofen, when consumed in combination with resistance training, do not inhibit and appear to enhance muscle hypertrophy and strength gains in older adults. The present findings coupled with previous short-term exercise studies provide convincing evidence that the COX pathway(s) are involved in the regulation of muscle protein turnover and muscle mass in humans.cyclooxygenase; prostaglandin; sarcopenia SARCOPENIA, DEFINED AS THE loss of skeletal muscle mass, is a debilitating clinical condition associated with old age (13,40). This age-related loss of muscle mass is associated with a loss of muscle strength and function, a reduced functional independence, and a financial burden to the US healthcare system estimated at $20 billion per year (19,23,24,51). One of the most proven treatments for sarcopenia is resistance exercise training, which in...

The purpose of this investigation was to examine the activation (phosphorylation) and total protein content of MAPK signalling cascade proteins (ERK 1/2, p90RSK, Mnk 1, eIF4E, p38 MAPK, JNK/SAPK, MKP 1) at rest and following exercise, in sedentary young and old men. Eight young (22 +/- 1 years; YM) and eight old (79 +/- 3 years; OM) men underwent a resting muscle biopsy of the vastus lateralis; they then performed a knee extensor resistance exercise session (29 contractions at approximately 70 % of max), followed by a post-exercise biopsy. Western immunoblot analysis demonstrated that the OM had higher resting phosphorylation of ERK 1/2, p90RSK, Mnk 1, p38 MAPK and JNK/SAPK proteins versus YM (P < 0.05). The resistance exercise bout caused an increase in phosphorylation of the ERK 1/2, p90RSK and Mnk 1 proteins (P < 0.05) in the YM. Conversely, the OM had a decrease in ERK 1/2, p90RSK, Mnk 1, p38 MAPK and JNK/SAPK phosphorylation (P < 0.05) after the exercise bout. Neither group showed a change in eIF4E phosphorylation. The total amount of protein expression of the MAPK signalling proteins was not different between the YM and OM, except that there was a higher (P < 0.05) MKP 1 protein content in the OM. This investigation is the first to provide evidence that MAPK proteins are differentially activated at rest and in response to a bout of resistance exercise in skeletal muscle of young and old men. These findings may have implications for other processes (e.g. transcription and translation) involved in skeletal muscle type and growth, when examining the changes occurring with ageing muscle before and after resistance exercise/training.

Tendons are important for optimal muscle force transfer to bone and play a key role in functional ability. Changes in tendon properties with aging could contribute to declines in physical function commonly associated with aging. We investigated the in vivo mechanical properties of the patellar tendon in 37 men and women [11 young (27 +/- 1 yr) and 26 old (65 +/- 1 yr)] using ultrasonography and magnetic resonance imaging (MRI). Patella displacement relative to the tibia was monitored with ultrasonography during ramped isometric contractions of the knee extensors, and MRI was used to determine tendon cross-sectional area (CSA) and signal intensity. At peak force, patellar tendon deformation, stress, and strain were 13 (P = 0.05), 19, and 12% less in old compared with young (P < 0.05). Additionally, deformation, stiffness, stress, CSA, and length were 18, 35, 41, 28, and 11% greater (P < 0.05), respectively, in men compared with women. After normalization of mechanical properties to a common force, no age differences were apparent; however, stress and strain were 26 and 22% higher, respectively, in women compared with men (P < 0.05). CSA and signal intensity decreased 12 and 24%, respectively, with aging (P < 0.05) in the midregion of the tendon. These data suggest that differences in patellar tendon in vivo mechanical properties with aging are more related to force output rather than an age effect. In contrast, the decrease in signal intensity indirectly suggests that the internal milieu of the tendon is altered with aging; however, the physiological and functional consequence of this finding requires further study.

The purpose of this study was to investigate whole muscle and single muscle fiber adaptations in very old men in response to progressive resistance training (PRT). Six healthy independently living old men (82 +/- 1 yr; range 80-86 yr, 74 +/- 4 kg) resistance-trained the knee extensors (3 sets, 10 repetitions) at approximately 70% one repetition maximum 3 days/wk for 12 wk. Whole thigh muscle cross-sectional area (CSA) was assessed before and after PRT using computed tomography (CT). Muscle biopsies were obtained from the vastus lateralis before and after the PRT program. Isolated myosin heavy chain (MHC) I and IIa single muscle fibers (n = 267; 142 pre; 125 post) were studied for diameter, peak tension, shortening velocity, and power. An additional set of isolated single muscle fibers (n = 2,215; 1,202 pre; 1,013 post) was used to identify MHC distribution. One repetition maximum knee extensor strength increased (P < 0.05) 23 +/- 4 kg (56 +/- 4 to 79 +/- 7 kg; 41%). Muscle CSA increased (P < 0.05) 3 +/- 1 cm2 (120 +/- 7 to 123 +/- 7 cm2; 2.5%). Single muscle fiber contractile function and MHC distribution were unaltered with PRT. These data indicate limited muscle plasticity at the single-muscle fiber level with a resistance-training program among the very old. The minor increases in whole muscle CSA coupled with the static nature of the myocellular profile indicate that the strength gains were primarily neurological. These data contrast typical muscle responses to resistance training in young ( approximately 20 yr) and old ( approximately 70 yr) humans and indicate that the physiological regulation of muscle remodeling is adversely modified in the oldest old.

Raue, Ulrika, Dustin Slivka, Bozena Jemiolo, Chris Hollon, and Scott Trappe. Myogenic gene expression at rest and after a bout of resistance exercise in young (18 -30 yr) and old (80 -89 yr) women. J Appl Physiol 101: 53-59, 2006. First published April 6, 2006 doi:10.1152/japplphysiol.01616.2005.-The purpose of this study was to investigate mRNA expression of several key skeletal muscle myogenic controllers; myogenic differentiation factor (MyoD), muscle regulatory factor 4 (MRF4), myogenic factor 5 (Myf5), myogenin, myostatin, and myocyte enhancer factor 2 (MEF2) at rest and 4 h after a single bout of resistance exercise (RE) in young and old women. Eight young women (YW; 23 Ϯ 2 yr, 67 Ϯ 5 kg) and six old women (OW; 85 Ϯ 1 yr, 67 Ϯ 4 kg) performed 3 sets of 10 repetitions of bilateral knee extensions at 70% of one repetition maximum. Muscle biopsies were taken from the vastus lateralis before and 4 h after RE. Using real-time RT PCR, mRNA from the muscle samples was amplified and normalized to GAPDH. At rest, OW expressed higher (P Ͻ 0.05) levels of MyoD, MRF4, Myf5, myogenin, and myostatin compared with YW. In response to RE, there was a main time effect (P Ͻ 0.05) for the YW and OW combined in the upregulation of MyoD (2.0-fold) and MRF4 (1.4-fold) and in the downregulation of myostatin (2.2-fold). There was a trend (P ϭ 0.08) for time ϫ age interaction in MRF4. These data show that old women express higher myogenic mRNA levels at rest. The higher resting myogenic mRNA levels in old women may reflect an attempt to preserve muscle mass and function. When challenged with RE, old women appear to respond in a similar manner as young women. mRNA; skeletal muscle; muscle regulatory factors; real-time reverse transcriptase-polymerase chain reaction AGING RODENT (1, 31) AND HUMAN (16, 23) skeletal muscle has been shown to express high mRNA levels of muscle regulatory factors.