The purpose of the study was to examine the effects of switching from a habitual diet to a carbohydrate-restricted diet (CRD) on strength and power performance in trained men (n = 16) and women (n = 15). Subjects performed handgrip dynamometry, vertical jump, 1RM bench press and back squat, maximum-repetition bench press, and a 30-second Wingate anaerobic cycling test after consuming a habitual diet (40.7% carbohydrate, 22.2% protein, and 34.4% fat) for 7 days and again after following a CRD (5.4% carbohydrate, 35.1% protein, and 53.6% fat) for 7 days. Before both testing sessions, body weight and composition were examined using bioelectrical impedance analysis. Three 2 × 2 multiple analyses of variance were used to compare performance variables between the habitual diet and CRD. Subjects consumed significantly fewer (p < 0.05) total kilocalories during the CRD (2,156.55 ± 126.7) compared with the habitual diet (2,537.43 ± 99.5). Body mass decreased significantly (p < 0.05). Despite a reduction in body mass, strength and power outputs were maintained for men and women during the CRD. These findings may have implications for sports that use weight classes, and in which strength and power are determinants of success. A CRD may be an alternative method for short-term weight loss without compromising strength and power outputs. The use of a 7-day CRD could replace weight loss methods employing severe dehydration before competition.

Numerous studies have examined the effects that body composition has on performance in football, soccer, and ice hockey; yet, there are no similar studies examining this relationship in men's lacrosse. The purpose of the study was to examine the physiological profiles and the relationship between body composition and performance in aerobic and anaerobic tests. Fifty-four (19.63 ± 1.21 years; 178.53 ± 6.17 cm; 81.66 ± 14.96 kg) Division III intercollegiate athletes participated. Performance tests, including a 1 repetition maximum power clean (PC), body weight (lbs), bench press repetitions, parallel bar triceps dips to fatigue (DR), two 300-yard shuttles, and a 1-mile run (MT), were completed after the completion of fall preseason practices. Body composition was estimated using air-displacement plethysmography. Correlation coefficients determined relationships between percent body fat (%BF), fat-free mass (FFM), and testing variables. Increased %BF was negatively correlated to DR (r = -0.36, p = 0.01) whereas positively correlated to each 300-yard shuttle time (T1 and T2), total 300-yard shuttle time (TT), and MT (r = 0.64, p = 0.00; r = 0.68, p = 0.00; r = 0.69, p = 0.00; and r = 0.44, p = 0.00, respectively). Increased FFM was positively correlated with PC (r = 0.58, p = 0.00) yet not correlated (p ≥ 0.05) with other variables. Results indicated that increased %BF might be a detriment to the repetitive anaerobic performance and aerobic capacity vital to on-field lacrosse performance. Body composition also demonstrated a significant relationship to moving internal vs. external resistances.

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