Revista de Medicina Desportiva (English) March 2018 - Page 7

well as the efficiency of the O2 consumption and the lactic threshold ), other factors are also themselves as determinants in the athlete ’ s sporting success , notably complexes factors of a motivational and sociological nature . 7 The study design used in this work also seems to have little transfer for elite athletes , as it implied total interruption of training for two days . In relation to the stress fractures , it should also be stressed out that the these only represent up to 20 % of the injuries sustained in the sports , and even in some sports it may represent only 0.7 %. 8 In women , other factors such as amenorrhea also seem related to their occurrence 9 , so these results should not be extrapolated to the female gender , due to the physiological and hormonal complexity involved .
This overvaluation of short-term results recalls the excessive importance that has already been given to the immediate replacement of carbohydrates after the exercise , which is only justified when the interval between workouts is less than 8 hours and loses relevance when it is superior . 10 In the same line of reasoning , it seems a risky step to translate effects into intermediate markers for an outcome more final , such as bone density or risk of fractures . It is therefore urgent to carry out studies that can measure directly the bone mineral density in response to these intermediate markers , such as the radiological Dual Energy Densitometry ( DED ). This work , again recalls the enormous importance given to the impact of protein intake on the short-term muscular protein synthesis assuming that it would inevitably translate into muscular hypertrophy , which is not so linear . 11 Last , and not least , it is a frank limitation of this study not to have corrected the values of the markers for the hemoconcentration , as well as not to have presented data of the intake of other important nutrients for bone health , other than calcium , like magnesium and vitamins A and D . In future studies , it would also be interesting to evaluate the effect of exercise intake on days of multiple training sessions , particularly at night , since there is a zenith at this time of day in the biochemicals markers of bone turnover . 8
References
1 . Townsend R , Elliot-Sale KJ , Currell K , Tang J , Fraser WD , Sale C . The Effect of Postexercise Carbohydrate and Protein Ingestion on Bone Metabolism . Med Sci Sport Exerc . 2017 Jun ; 49 ( 6 ): 1209-18 .
2 . American Dietetic Association , Dietitians of Canada , American College of Sports Medicine , Rodriguez NR , Di Marco NM , Langley S . American College of Sports Medicine position stand . Nutrition and athletic performance . Med Sci Sports Exerc . 2009 ; 41 ( 3 ): 709-31 .
3 . Scott JPR , Sale C , Greeves JP , Casey A , Dutton J , Fraser WD . The effect of training status on the metabolic response of bone to an acute bout of exhaustive treadmill running . J Clin Endocrinol Metab . 2010 ; 95 ( 8 ): 3918-25 .
4 . Sale C , Varley I , Jones TW , James RM , Tang JCY , Fraser WD , et al . Effect of carbohydrate feeding on the bone metabolic response to running . J Appl Physiol . 2015 ; 119 ( 7 ): 824-30 .
5 . Scott JPR , Sale C , Greeves JP , Casey A , Dutton J , Fraser WD . Effect of fasting versus feeding on the bone metabolic response to running . Bone . 2012 Dec ; 51 ( 6 ): 990-9 .
6 . de Oliveira EP , Burini RC , Jeukendrup A . Gastrointestinal complaints during exercise : prevalence , etiology , and nutritional recommendations . Sports Med . 2014 ; 44 Suppl 1 ( S1 ): S79-85 .
7 . Joyner MJ , Coyle EF . Endurance exercise performance : the physiology of champions . J Physiol . 2008 ; 586 ( 1 ): 35-44 .
8 . Schlemmer A , Hassager C . Acute fasting diminishes the circadian rhythm of biochemical markers of bone resorption . Eur J Endocrinol . 1999 ; 140 ( 4 ): 332-7 .
9 . Duckham RL , Peirce N , Meyer C , Summers GD , Cameron N , Brooke-Wavell K . Risk factors for stress fracture in female endurance athletes : a cross-sectional study . BMJ Open . 2012 ; 2 ( 6 ).
10 . Burke LM , van Loon LJC , Hawley JA . Postexercise muscle glycogen resynthesis in humans . J Appl Physiol . 2017 ; 122 ( 5 ): 1055-67 .
11 . Damas F , Phillips SM , Libardi CA , Vechin FC , Lixandrão ME , Jannig PR , et al . Resistance training-induced changes in integrated myofibrillar protein synthesis are related to hypertrophy only after attenuation of muscle damage . J Physiol . 2016 ; 594 ( 18 ): 5209-22 .
Revista de Medicina Desportiva informa march 2018 · 5
well as the efficiency of the O2 con- sumption and the lactic threshold), other factors are also themselves as determinants in the athlete’s sporting success, notably complexes factors of a motivational and socio- logical nature. 7 The study design used in this work also seems to have little transfer for elite athletes, as it implied total interruption of training for two days. In relation to the stress fractures, it should also be stressed out that the these only represent up to 20% of the injuries sustained in the sports, and even in some sports it may represent only 0.7%. 8 In women, other factors such as amen- orrhea also seem related to their occurrence 9 , so these results should not be extrapolated to the female gender, due to the physiological and hormonal complexity involved. This overvaluation of short-term results recalls the excessive impor- tance that has already been given to the immediate replacement of carbohydrates after the exercise, which is only justified when the interval between workouts is less than 8 hours and loses relevance when it is superior. 10 In the same line of reasoning, it seems a risky step to translate effects into intermediate markers for an outcome more final, such as bone density or risk of frac- tures. It is therefore urgent to carry out studies that can measure directly the bone mineral density in response to these intermediate markers, such as the radiological Dual Energy Densitometry (DED). This work, again recalls the enormous importance given to the impact of protein intake on the short-term muscular protein synthesis assuming that it would inevitably translate into muscular hypertrophy, which is not so lin- ear. 11 Last, and not least, it is a frank limitation of this study not to have corrected the values of the markers for the hemoconcentration, as well as not to have presented data of the intake of other important nutrients for bone health, other than calcium, like magnesium and vitamins A and D. In future studies, it would also be interesting to evaluate the effect of exercise intake on days of mul- tiple training sessions, particularly at night, since there is a zenith at this time of day in the biochemicals markers of bone turnover. 8 References 1. Townsend R, Elliot-Sale KJ, Currell K, Tang J, Fraser WD, Sale C. The Effect of Postexercise Carbohydrate and Protein Ingestion on Bone Metabolism. Med Sci Sport Exerc. 2017 Jun; 49(6):1209-18. 2. American Dietetic Association, Dietitians of Canada, American College of Sports Medicine, Rodriguez NR, Di Marco NM, Langley S. American College of Sports Medicine position stand. Nutrition and athle- tic performance. Med Sci Sports Exerc. 2009; 41(3):709-31. 3. Scott JPR, Sale C, Greeves JP, Casey A, Dut- ton J, Fraser WD. The effect of training status on the metabolic response of bone to an acute bout of exhaus FfRG&VF֖'Vr6ƖVF7&WF"#R3#RB6R2f&WW2ErW2$Fp5g&6W"tBWBVffV7Bb6&&G&FPfVVFrFR&RWF&Ɩ2&W76RF'VЦr6#Sr#B3R66GB"6R2w&VWfW266WGWGFg&6W"tBVffV7Bbf7FrfW'7W0fVVFrFR&RWF&Ɩ2&W76RF'VЦr&R#"FV3SbӒbFRƗfV&U'W&$2WVVG'Wv7G&FW7F6G2GW&rWW&66S&WfV6RWFwBWG&F&V6ЦVFF27'G2VB#CCB7W33sӃRrW"Ԣ6RTbVGW&6RWW&66PW&f&6SFR6wb626#Sb3RCBࣂ66VW"76vW"27WFRf7FpF֖6W2FR6&6F&Fb&6V֖6&W'2b&R&W6'FWW"VF7&CB33"r࣒GV6$V&6RWW"27VW'0tB6W&'&RvfV&6f7F'2f"7G&W72g&7GW&RfVRVGW&6PFWFW37&726V7F7GVG$ԢV##"b'W&RfĤ2vW7FRЧW&66RW66Rvǖ6vV&W7FW62V2ढ6#s#"RSRcrF2bƗ24Ɩ&&F4fV6d2ƗG,:6Rr"WB&W67F6PG&r֖GV6VB6vW2FVw&FVBזfЦ'&"&FV7FW62&R&VFVBFW'G&ЧǒgFW"GFVVFbW66RFvR6#cSBS##"&Wf7FFRVF6FW7'Fff&&6# +rP