Effect of Magnesium Lactate Dihydrate and Calcium Lactate Monohydrate on 20-km Cycling Time Trial Performance

Short-Term Magnesium Supplementation Has Modest Detrimental Effects on Cycle Ergometer Exercise Performance and Skeletal Muscle Mitochondria and Negligible Effects on the Gut Microbiota: A Randomized Crossover Clinical Trial

Background/Objectives: Although the importance of magnesium for overall health and physiological function is well established, its influence on exercise performance is less clear. The primary study objective was to determine the influence of short-term magnesium supplementation on cycle ergometer exercise performance. The hypothesis was that magnesium would elicit an ergogenic effect. Methods: A randomized, double-blind, placebo-controlled, two-period crossover design was used to study men and women who were regular exercisers. Fifteen participants ingested either a placebo or magnesium chloride (MgCl2 300 mg) twice per day, for 9 days, separated by a 3-week washout. During days 8 and 9, participants completed a battery of cycle ergometer exercise tests, and whole blood, vastus lateralis, and stools were sampled. The primary outcomes were the maximal oxygen uptake (VO2max), a simulated 10 km time trial, and the sprint exercise performance. Additional outcomes included skeletal muscle mitochondrial respiration, and, on account of the known laxative effects of magnesium, the gut microbiota diversity. Results: Compared with a placebo, MgCl2 supplementation increased the circulating ionized Mg concentration (p < 0.03), decreased the VO2max (44.4 ± 7.7 vs. 41.3 ± 8.0 mL/kg/min; p = 0.005), and decreased the mean power output during a 30 s sprint (439 ± 88 vs. 415 ± 88 W; p = 0.03). The 10 km time trial was unaffected (1282 ± 126 vs. 1281 ± 97 s; p = 0.89). In skeletal muscle, MgCl2 decreased mitochondrial respiration in the presence of fatty acids at complex II (p = 0.04). There were no significant impacts on the gut microbiota richness (CHAO1; p = 0.68), Shannon's Diversity (p = 0.23), or the beta-diversity (Bray-Curtis distances; p = 0.74). Conclusions: In summary, magnesium supplementation had modest ergolytic effects on cycle ergometer exercise performance and mitochondrial respiration. We recommend that regular exercisers, free from hypomagnesemia, should not supplement their diet with magnesium.

Acute Response of Calcium Lactate Supplementation on the Athletic Performance of Soccer Players Under the Age of 15

PURPOSE

To determine the acute response of lactate supplementation on athletic performance.

METHOD

Fifteen athletes under the age of 15 performed the following 4 sessions in a nonrandomized order: (1) familiarization, (2) control, (3)  participants ingested calcium lactate (21.5 mg·kg-1 body mass), and (4) participants ingested a placebo (PLA, calcium carbonate, 21.5 mg·kg-1 body mass). The capsules were randomly offered and consumed 60 minutes before the physical tests. To assess the physical performance, the athletes executed squat jump, countermovement squat jump, 20-m linear sprint, change of direction test, and running anaerobic sprint test.

RESULTS

There were no significant differences between conditions for squat jump, countermovement jump, change of direction, and minimum power obtained in the running anaerobic sprint test (P > .05). Conversely, we observed a worse performance (P < .05) in the 20-m linear sprint test in the PLA and lactate conditions compared with control (P < .05). The lactate condition worsened performance during running anaerobic sprint test for peak power, mean power, and fatigue index compared with control and PLA (P < .05).

CONCLUSIONS

Calcium lactate supplementation worsened repetitive running sprint ability and 20-m sprint performance. However, lactate supplementation does not affect jump or agility capacity. Therefore, calcium lactate supplementation seems to be an ineffective strategy to improve anaerobic and neuromuscular performance in soccer players 15 years of age or less.

Effects of Oral Lactate Supplementation on Acid-Base Balance and Prolonged High-Intensity Interval Cycling Performance

Lactate is an important energy intermediate and metabolic buffer, and may be ergogenic. We investigated if lactate supplementation is an effective approach to enhance the exercise performance and acid-base balance of trained cyclists during exercise devised to simulate the demands of endurance road race cycling. Sixteen endurance-trained male cyclists (V·O2max 59 ± 7 mL·kg-1·min-1) consumed 120 mg·kg-1 body mass of lactate or a placebo 70 min prior to performing an exercise performance test, comprising five repeated blocks consisting of 1 km and 4 km time trials interspersed with 10 min of moderate-intensity exercise. Blood acid-base balance (including [H+] and [HCO3-]), heart rate, perceived exertion, and gastro-intestinal tolerance were assessed. There was no effect of lactate supplementation on exercise performance (p = 0.320), despite a reduction in RPE (p = 0.012) and increases in [SID] (p = 0.026) and [HCO3-] (p = 0.041). In addition, gastro-intestinal side effects were observed, but there was no effect on heart rate. Lactate supplementation did not improve exercise performance, despite positive changes in acid-base balance and RPE. This suggests that the alkalising effects of the supplement can reduce perceived effort, but these benefits do not translate into performance improvements.

The Influence of Acute Oral Lactate Supplementation on Responses to Cycle Ergometer Exercise: A Randomized, Crossover Pilot Clinical Trial

The purpose of this study was to investigate the potential ergogenic effects of an oral lactate supplement. For this double-blind, randomized, placebo-controlled crossover design, fifteen recreational exercisers (nine males, six females) ingested a placebo or a commercially available lactate supplement prior to cycle ergometer exercise. Primary outcomes included peak oxygen uptake (VO2peak; via indirect calorimetry), VO2 at the ventilatory threshold, and work rate at the lactate threshold (arterialized venous blood from a heated hand) determined during incremental exercise to fatigue, and power output during a 20-min cycling time trial. Compared with placebo, the oral lactate supplement (19 ± 1 mg/kg body mass) did not influence VO2peak (placebo: 44.3 ± 7.8 vs. oral lactate: 44.3 ± 7.1 mL/kg/min (mean ± SD); p = 0.87), VO2 at the ventilatory threshold (placebo: 1.63 ± 0.25 vs. oral lactate: 1.65 ± 0.23 L/min; p = 0.82), or work rate at the lactate threshold (placebo: 179 ± 69 vs. oral lactate: 179 ± 59 W; p = 0.41). Throughout the 20-min time trial, the work rate was slightly greater (4%) with oral lactate (204 ± 41 W) compared with placebo (197 ± 41 W; main effect of treatment p = 0.02). Collectively, these data suggest that this commercially available lactate supplement did not acutely influence the physiological responses to incremental cycle ergometer exercise but elicited a modest ergogenic effect during the short-duration time trial.

Effects of magnesium supplementation on muscle soreness in different type of physical activities: a systematic review

BACKGROUND

Magnesium is a micronutrient and an intracellular cation responsible for different biochemical reactions involved in energy production and storage, control of neuronal and vasomotor activity, cardiac excitability, and muscle contraction. Magnesium deficiency may result in impaired physical performance. Moreover, magnesium plays an important role on delayed onset muscle soreness after training. Thus, physically active individuals and sport specialists have to pay attention to magnesium supplementation (MgS). However, the type, timing and dosage of magnesium intake are not well elucidated yet. Hence, we aimed to systematically review the literature regarding the effects of MgS on muscle soreness in physically active individuals. We focused exclusively on MgS, excluding those studies in which magnesium was administered together with other substances.

METHODS

Three electronic databases and literature sources (PUBMED, SCOPUS and Web of Sciences-Core Collection) were searched, in accordance with PRISMA guidelines. After the database search, 1254 articles were identified, and after excluding duplicates, 960 articles remained. Among these, 955 were excluded following the title and abstract screening. The remaining 5 articles were screened in full text and 4 study met the eligibility criteria.

RESULTS

These studies showed that MgS reduced muscle soreness, improved performance, recovery and induced a protective effect on muscle damage.

CONCLUSION

To reach these positive effects, individuals engaged in intense exercise should have a Mg requirement 10-20% higher than sedentary people, to be taken in capsules and 2 h before training. Moreover, it is suggested to maintain magnesium levels in the recommended range during the off-season.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42024501822.

Extracellular Buffering Supplements to Improve Exercise Capacity and Performance: A Comprehensive Systematic Review and Meta-analysis

BACKGROUND

Extracellular buffering supplements [sodium bicarbonate (SB), sodium citrate (SC), sodium/calcium lactate (SL/CL)] are ergogenic supplements, although questions remain about factors which may modify their effect.

OBJECTIVE

To quantify the main effect of extracellular buffering agents on exercise outcomes, and to investigate the influence of potential moderators on this effect using a systematic review and meta-analytic approach.

METHODS

This study was designed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Three databases were searched for articles that were screened according to inclusion/exclusion criteria. Bayesian hierarchical meta-analysis and meta-regression models were used to investigate pooled effects of supplementation and moderating effects of a range of factors on exercise and biomarker responses.

RESULTS

189 articles with 2019 participants were included, 158 involving SB supplementation, 30 with SC, and seven with CL/SL; four studies provided a combination of buffering supplements together. Supplementation led to a mean estimated increase in blood bicarbonate of + 5.2 mmol L^-1 (95% credible interval (CrI) 4.7-5.7). The meta-analysis models identified a positive overall effect of supplementation on exercise capacity and performance compared to placebo [ES_0.5 = 0.17 (95% CrI 0.12-0.21)] with potential moderating effects of exercise type and duration, training status and when the exercise test was performed following prior exercise. The greatest ergogenic effects were shown for exercise durations of 0.5-10 min [ES_0.5 = 0.18 (0.13-0.24)] and > 10 min [ES_0.5 = 0.22 (0.10-0.33)]. Evidence of greater effects on exercise were obtained when blood bicarbonate increases were medium (4-6 mmol L^-1) and large (> 6 mmol L^-1) compared with small (≤ 4 mmol L^-1) [β_Small:Medium = 0.16 (95% CrI 0.02-0.32), β_Small:Large = 0.13 (95% CrI - 0.03 to 0.29)]. SB (192 outcomes) was more effective for performance compared to SC (39 outcomes) [β_SC:SB = 0.10 (95% CrI - 0.02 to 0.22)].

CONCLUSIONS

Extracellular buffering supplements generate large increases in blood bicarbonate concentration leading to positive overall effects on exercise, with sodium bicarbonate being most effective. Evidence for several group-level moderating factors were identified. These data can guide an athlete's decision as to whether supplementation with buffering agents might be beneficial for their specific aims.

Can Magnesium Enhance Exercise Performance?

Magnesium (Mg) is an essential mineral that plays a critical role in the human body. It takes part in the process of energy metabolism and assists the maintenance of normal muscle function. A number of studies evaluated the association between Mg status/supplementation and exercise performance and found that the need for Mg increased as individuals’ physical activity level went up. Animal studies indicated that Mg might improve exercise performance via enhancing glucose availability in the brain, muscle and blood; and reducing/delaying lactate accumulation in the muscle. The majority of human studies focused on physiological effects in blood pressure, heart rate and maximal oxygen uptake (VO₂ max), rather than direct functional performances. Some cross-sectional surveys demonstrated a positive association between Mg status and muscle performance, including grip strength, lower-leg power, knee extension torque, ankle extension strength, maximal isometric trunk flexion, rotation, and jumping performance. Additionally, findings from intervention studies showed that Mg supplementation might lead to improvements in functional indices such as quadriceps torque. Moreover, Mg supplementation could improve gait speed and chair stand time in elderly women. This comprehensive review summarized the literature from both animal and human studies and aimed to evaluate scientific evidence on Mg status/supplementation in relation to exercise performance.

Effect of lactate supplementation and sodium bicarbonate on 40-km cycling time trial performance

The use of nutritional supplements to improve sporting performance and increase training adaptations is commonplace among athletes and is an expanding market in terms of product choice and availability. The purpose of this study was to examine the effects of 2 ergogenic aids with extracellular blood buffering potential, namely sodium bicarbonate (NaHCO3) and a lactate supplement, during a 40-km cycling time trial. Seven recreationally active men (age, 22.3 ± 3.3 years; height, 182.5 ± 6.5 cm; body mass, 79.2 ± 6.3 kg) completed five 40-km cycling time trials, including a familiarization trial in a randomized, blind, double placebo-controlled design. Subjects ingested (a) 300 mg·kg-1 body mass NaHCO3 (BICARB), (b) 45 mg·kg-1 body mass sodium chloride (PL-BICARB) as the placebo for the NaHCO3 trial, (c) 1115 mg lactate (LACTATE), or (d) plain flour as the placebo for the lactate trial (PL-LACTATE) 60 minutes before exercise. There was no significant difference in performance between the 4 conditions (p > 0.05). Although NaHCO3 ingestion induced significant changes in all the acid-base variables (all p < 0.05), no significant change was seen following lactate ingestion (p > 0.05). Subjects in the LACTATE condition did have a significantly higher heart rate (p < 0.05) without experiencing any greater perceived exertion (p > 0.05) than the other 3 conditions. Neither NaHCO3 nor lactate supplementation seem to improve 40-km cycling time trial performance. However, the potential benefits following LACTATE regarding perceived exertion require further research.