Creatine supplementation: effects on blood creatine kinase activity responses to resistance exercise and creatine kinase activity measurement

Abstract

The purpose of this study was to determine the effects of creatine supplementation and exercise on the integrity of muscle fiber, as well as the effect of the supplementation on the creatine kinase (CK) assay measurement. Forty-nine sedentary individuals participated in a double-blind study and were divided into two groups: C (n=26) received 4x5-day packages of 0.6 g.kg -1 of body weight contained 50% of creatine + 50% of dextrose, and P (n=23) received packages containing only dextrose. On the first day the groups performed a 1RM test for bench press, seated row, leg extension, leg curl and leg press. On D 7 they received the supplements. On the fourteenth day, they performed a training session of five exercises, each in three sets of ten repetitions at 75% of 1RM. Blood was collected before (D 14 ) and after the exercise session (D 15 ). Differing levels of blood creatine were tested to determine the influence on the assay measurements of CK. ANOVA and Tukey's post-hoc tests were used to compare groups and different times of study protocol (P<0.05). No changes were observed in CK activity of the groups from D 0 , D 7 and D 14 . On D 15 CK activity increases 140% (women) and 200% (men). There was no difference in CK activity between groups. Blood creatine levels up to 5mM produced no significant effect on CK assay results. CK activity increased after resistance exercise, while creatine supplementation produced no difference in the muscle cellular integrity nor compromised assay methodology.Uniterms: Physical exercise/effects. Creatine/supplementation/effects. Creatine Kinase/assay. Muscle fibers.O objetivo do presente estudo foi determinar o efeito da suplementação de creatina e do exercício na integridade das fibras musculares e, também, o efeito da suplementação na técnica de mensuração da atividade da creatina kinase (CK). Quarenta e nove sedentários participaram de um estudo duplo-cego e foram divididos em dois grupos: C (n=26) que receberam 4x5 dias embalagens com 0,6 g.kg -1 de massa corporal com 50% de creatina + 50% de dextrose, e P (n=23) que receberam embalagens contendo apenas dextrose. No primeiro dia, eles realizaram o teste de 1RM para os exercícios supino reto, remada sentada, cadeira extensora, mesa flexora, e leg press. No D 7 receberam os suplementos. No décimo quarto dia eles realizaram uma sessão de treinos com os cinco exercícios, cada um com 3x10 repetições a 75% de 1RM. Sangue foi coletado antes (D 14 ) e depois da sessão de exercícios (D 15

Effect of Varying Rest Intervals Between Sets of Assistance Exercises on Creatine Kinase and Lactate Dehydrogenase Responses

“…An enzymatic method was used for enzyme activity analysis with commercial kits (BioTe´cnica --Brazil) in Cobas Mira Plus analyzer (Roche, Basel, Switzerland). The same methodology was used in Machado et al (12) and that there was high reproducibility between measurements (intraclass coefficient r = 0.99).…”

Perspectives on Exertional Rhabdomyolysis

“…Several groups have investigated the effects of creatine supplementation on recovery from intense resistance exercise that is more typical of real-world training [115, 139, 140]. Rawson et al [140] examined the effects of creatine supplementation (0.3 g/kg for 5 days; followed by 0.03 g/kg for 5 days) on recovery from a high-intensity squat workout (five sets of 15–20 reps at 50% 1-RM) and found no effect of the creatine on post-exercise strength, serum CK and LDH, ROM, swelling, and DOMS.…”

“…Rawson et al [140] examined the effects of creatine supplementation (0.3 g/kg for 5 days; followed by 0.03 g/kg for 5 days) on recovery from a high-intensity squat workout (five sets of 15–20 reps at 50% 1-RM) and found no effect of the creatine on post-exercise strength, serum CK and LDH, ROM, swelling, and DOMS. Machado et al [139] found no difference in post-exercise CK between creatine- (20 g/day for 5 days) and placebo-supplemented subjects following three sets of ten repetitions of five exercises performed at 75% of 1-RM. Recently, Veggi et al [115] showed that creatine supplementation (20 g/day for 5 days) attenuated the increase in CK and DOMS and decrease in ROM to a greater extent than a placebo following repeated bouts of resistance exercise (four sets of biceps curls at 75% 1-RM).…”

“…Together, these papers indicate that creatine supplementation does not disrupt and may enhance recovery from resistance exercise with both concentric and eccentric contractions. The effects of creatine supplementation on resistance exercise-induced muscle damage are summarized in Table 1 [115, 139, 140]. …”

Oral Creatine Supplementation Augments the Repeated Bout Effect

“…Several groups have assessed the effects of creatine supplementation on markers of muscle damage following stressful resistance (Cooke et al, 2009;Machado et al, 2009;Rahimi, 2011;Rawson et al, 2007;Rawson et al, 2001;Rosene et al, 2009;Warren et al, 2000) and endurance (Bassit et al, 2008;Bassit et al, 2010;Santos et al, 2004) exercise. Collectively, these studies indicate that creatine either reduces damage and enhances recovery from stressful exercise (Bassit et al, 2008;Bassit et al, 2010;Cooke et al, 2009;Rahimi, 2011;Rosene et al, 2009;Santos et al, 2004) or has no effect (Machado et al, 2009;Rawson et al, 2007;Rawson et al, 2001;Warren et al, 2000). Conflicting results could be related to differences between exercise protocols.…”