882 Journal of Strength and Conditioning Research, 2007, 21(3), 882–887  2007 National Strength & Conditioning Association THE EFFECTS OF TEN WEEKS OF RESISTANCE AND COMBINED PLYOMETRIC/SPRINT TRAINING WITH THE MERIDIAN ELYTE ATHLETIC SHOE ON MUSCULAR PERFORMANCE IN WOMEN NICHOLAS A. RATAMESS, 1 WILLIAM J. KRAEMER, 2,3 JEFF S. VOLEK, 2 DUNCAN N. FRENCH, 2 MARTYN R. RUBIN, 2 ANA L. GO ´ MEZ, 2 ROBERT U. NEWTON, 3 AND CARL M. MARESH 2 1 Department of Health and Exercise Science, The College of New Jersey, Ewing, New Jersey 08628; 2 Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, Connecticut 06269; 3 School of Biomedical and Sports Science, Edith Cowan University, Joondalup, WA, Australia. ABSTRACT. Ratamess, N.A., W.J. Kraemer, J.S. Volek, D.N. French, M.R. Rubin, A.L. Go ´mez, R.U. Newton, and C.M. Maresh. The effects of ten weeks of resistance and combined plyometric/ sprint training with the Meridian Elyte athletic shoe on mus- cular performance in women. J. Strength Cond. Res. 21(3):882– 887. 2007.—The purpose of this investigation was to examine the combined effects of resistance and sprint/plyometric training with or without the Meridian Elyte athletic shoe on muscular performance in women. Fourteen resistance-trained women were randomly assigned to one of 2 training groups: (a) an ath- letic shoe (N = 6) (AS) group or (b) the Meridian Elyte (N = 8) (MS) group. Training was performed for 10 weeks and consisted of resistance training for 2 days per week and 2 days per week of sprint/plyometric training. Linear periodized resistance train- ing consisted of 5 exercises per workout (4 lower body, 1 upper body) for 3 sets of 3–12 repetition maximum (RM). Sprint/ply- ometric training consisted of 5–7 exercises per workout (4–5 ply- ometric exercises, 40-yd and 60-yd sprints) for 3–6 sets with gradually increasing volume (8 weeks) followed by a 2-week ta- per phase. Assessments for 1RM squat and bench press, vertical jump, broad jump, sprint speed, and body composition were per- formed before and following the 10-week training period. Sig- nificant increases were observed in both AS and MS groups in 1RM squat (12.0 vs. 14.6 kg), bench press (6.8 vs. 7.4 kg), vertical jump height (3.3 vs. 2.3 cm), and broad jump (17.8 vs. 15.2 cm). Similar decreases in peak 20-, 40-, and 60-m sprint times were observed in both groups (20 m: 0.14 vs. 0.11 seconds; 40 m: 0.29 vs. 0.34 seconds; 60 m: 0.45 vs. 0.46 seconds in AS and MS groups, respectively). However, when sprint endurance (the dif- ference between the fastest and slowest sprint trials) was ana- lyzed, there was a significantly greater improvement at 60 m in the MS group. These results indicated that similar improve- ments in peak sprint speed and jumping ability were observed following 10 weeks of training with either shoe. However, high- intensity sprint endurance at 60 m increased to a greater extent during training with the Meridian Elyte athletic shoe. KEY WORDS. strength training, sprint endurance, sprint speed, jumping ability INTRODUCTION S printing speed and jumping ability are vital components to athletic success. Several train- ing devices designed to enhance both sprint- ing speed and jumping ability have been de- veloped. One such training device is the Strength Shoe. The Strength Shoe is a modified athletic shoe with a 4-cm–thick rubber platform attached to the front of the sole, designed to overload the Achilles tendon and posterior lower leg muscles (5, 20). Manufacturers of the Strength Shoe claimed superior performance enhance- ment with use of this specific model. However, research has not supported this claim (5, 20). Cook et al. (5) reported no significant difference in flexibility, strength, vertical jump, 40-yd dash, or calf girth among those training with or with- out the Strength Shoe over an 8-week training period. Por- cari et al. (20) reported no significant difference in 40-yd dash, vertical jump, or broad jump performance in those training with or without use of the Strength Shoe over a 10-week period. Both studies reported a higher rate of in- jury associated with use of this shoe. A newly designed model of resistance training shoe has been developed—the Meridian Elyte–series athletic shoe (Meridian Sports Inc., Indianapolis, IN). This shoe was de- signed specifically to improve the vertical phases of move- ment during sprinting and jumping; therefore, use of this shoe during lateral movements is contraindicated by its manufacturers. The positive angle character placed in the middle of the sole (see Figure 1) was designed to overload the plantar flexor muscles via greater stretch (range of mo- tion) during each repetition (compared to the experience of training with a typical athletic shoe). In a recent study we reported that the Meridian Elyte model shoe provided an ergogenic effect for improving vertical jump and 60-yd dash performance following only 8 weeks of combined resistance and sprint/plyometric training in men (16). Plantar flexor isometric rate of force development improved to a greater extent in subjects us- ing the Meridian Elyte shoe; therefore, it was suggested that greater elasticity in the plantar flexor muscles may have contributed to the enhanced sprinting and jumping ability (16). However, little is known concerning the ef- fects of this shoe on muscular performance over longer training periods, especially in women. Therefore, the pur- pose of this investigation was to examine the combined effects of resistance training and sprint/plyometric train- ing with or without the Meridian Elyte athletic shoe on muscular performance in women. METHODS Experimental Approach to the Problem This study was designed to examine the effects of training with the Meridian Elyte model shoe in resistance-trained women. Subjects were given either athletic shoes or Me- ridian Elyte shoes to wear during sprint/plyometric train- ing. Subjects in the Meridian shoe group were given the shoes 1 week prior to training for familiarization and were instructed on proper sprinting and jumping tech-