The SJ equation is a slightly more accurate equation than that derived from CMJ data. This equation should be used in the determination of peak power in place of the formulas developed by both Harman et al. and Lewis. Separate equations for males and females are unnecessary.

These data show efficacy for this cherry juice in decreasing some of the symptoms of exercise induced muscle damage. Most notably, strength loss averaged over the four days after eccentric exercise was 22% with the placebo but only 4% with the cherry juice.

Muscle damage is caused by strenuous and unaccustomed exercise, especially exercise involving eccentric muscle contractions, where muscles lengthen as they exert force. Damage can be observed both directly at the cellular level and indirectly from changes in various indices of muscle function. Several mechanisms have been offered to explain the etiology of the damage/repair process, including mechanical factors such as tension and strain, disturbances in calcium homeostasis, the inflammatory response, and the synthesis of stress proteins (heat shock proteins). Changes in muscle function following eccentric exercise have been observed at the cellular level as an impairment in the amount and action of transport proteins for glucose and lactate/H+, and at the systems level as an increase in muscle stiffness and a prolonged loss in the muscle's ability to generate force. This paper will briefly review factors involved in the damage/repair process and alterations in muscle function following eccentric exercise.

Power output at 40% of 1RM explained more of the variability in HGV than did power at 70% 1RM, suggesting that measures such as HGV that require a lower percentage of maximal strength to perform might be more sensitive to differences in contraction velocity. Because HGV is highly predictive of subsequent disability, future studies should evaluate the determinants of muscle power output at low external resistances.

These findings support the concurrent and predictive validity of the LLFDI. Results support the use of the LLFDI scales as a substitute for physical performance tests when self-report is a preferred data-collection format.

Eccentric exercise continues to receive attention as a productive means of exercise. Coupled with this has been the heightened study of the damage that occurs in early stages of exposure to eccentric exercise. This is commonly referred to as delayed onset muscle soreness (DOMS). To date, a sound and consistent treatment for DOMS has not been established. Although multiple practices exist for the treatment of DOMS, few have scientific support. Suggested treatments for DOMS are numerous and include pharmaceuticals, herbal remedies, stretching, massage, nutritional supplements, and many more. DOMS is particularly prevalent in resistance training; hence, this article may be of particular interest to the coach, trainer, or physical therapist to aid in selection of efficient treatments. First, we briefly review eccentric exercise and its characteristics and then proceed to a scientific and systematic overview and evaluation of treatments for DOMS. We have classified treatments into 3 sections, namely, pharmacological, conventional rehabilitation approaches, and a third section that collectively evaluates multiple additional practiced treatments. Literature that addresses most directly the question regarding the effectiveness of a particular treatment has been selected. The reader will note that selected treatments such as anti-inflammatory drugs and antioxidants appear to have a potential in the treatment of DOMS. Other conventional approaches, such as massage, ultrasound, and stretching appear less promising.

Autoregulatory progressive resistance exercise (APRE) is a method by which athletes increase strength by progressing at their own pace based on daily and weekly variations in performance, unlike traditional linear periodization (LP), where there is a set increase in intensity from week to week. This study examined whether 6 weeks of APRE was more effective at improving strength compared with traditional LP in division I College football players. We compared 23 division 1 collegiate football players (2.65 +/- 0.8 training years) who were trained using either APRE (n = 12) or LP (n = 11) during 6 weeks of preseason training in 2 separate years. After 6 weeks of training, improvements in total bench press 1 repetition maximum (1RM), squat 1RM, and repeated 225-lb bench press repetitions were compared between the APRE and LP protocol groups. Analysis of variance (ANOVA) and analysis of covariance (ANCOVA) were used to determine differences between groups. Statistical significance was accepted at p < or = 0.05. Autoregulatory progressive resistance exercise demonstrated greater improvement in 1RM bench press strength (APRE: 93.4 +/- 103 N vs. LP: -0.40 +/- 49.6 N; ANCOVA: F = 7.1, p = 0.02), estimated 1RM squat strength (APRE: 192.7 +/- 199 N vs. LP: 37.2 +/- 155 N; ANOVA: F = 4.1, p = 0.05) and the number of repetitions performed at a weight of 225 lb (APRE: 3.17 +/- 2.86 vs. LP: -0.09 +/- 2.40 repetitions; ANCOVA: F = 6.8, p = 0.02) compared with the LP group over the 6-week training period. Our findings indicate that the APRE was more effective than the LP means of programming in increasing the bench press and squat over a period of 6 weeks.

In this study we investigated force loss and recovery after eccentric exercise, and further characterized profound losses in muscle function (n = 192 subjects--98 males, 94 females; population A). Maximal voluntary contractile force (MVC) was assessed before, immediately after, and at 36 and 132 h after eccentric exercise. Two groups were then established (A1 and A2). Group A1 demonstrated a > 70% reduction in MVC immediately after exercise, but were recovering at 132 h after exercise. These subjects performed a follow-up MVC 26 days later (n = 32). Group A2 demonstrated a > 70% reduction in MVC immediately post-exercise, but still exhibited a > 65% reduction in force at 132 h post-exercise; these subjects also performed a follow-up MVC every 7 days until full recovery was established (n = 9). In population A, there was a 57% reduction in MVC immediately post-exercise and a 67% recovery by 132 h post-exercise (P < 0.01), with no significant gender differences (P > 0.05). In group A1, although more females (two-thirds) showed large force losses after exercise, these females demonstrated greater %MVC recovery at 132 h post-exercise (59% vs 44%) and at 26 days post-exercise (93% vs 81%) compared to the males. In group A2, MVC recovery occurred between 33 and 47 days post-exercise. In conclusion, 21% of all subjects showed a delayed recovery in MVC after high-force eccentric exercise. Although there were no significant gender differences in force loss, a disproportionately larger number of females demonstrated force reductions of > 70%. However, their recovery of force was more rapid than that observed for the males who also demonstrated a > 70% force loss.