Nutritional Timing, Part II Training in a fasted State Resistance Training

Nutritional Timing, Part II Training in a fasted state: Resistance Training

Should I eat before lifting?

First of, what did we establish in last entry about fast and endurance training that potentially can be applied towards resistance training?

1. Low carbohydrate availability forces the body to increases the usage of Fat as a fuel.
2. Chronic performance improvements (power, oxygen uptake, and time to exhaustion) has been seen when training in fasted state from both high and low intensity training.
3. Performance can be maintained if total amount of calories needed is consumed.
4. Fueling the body before training could result in a lower amount of fat usage during the session, but increase the calories used throughout the entire day.
5. Waking up at 5am or working out hungry is no fun.

Generally, the physical activity associated with weight loss is cardio. However, resistance training [1] and other high intensity training methods[2]  has shown to increase the rate of fat usage immediately after the training session and can therefore assist in both decreasing fat mass and increasing fat free mass. Additionally, the more muscle a person have relative to total body mass, the higher the amount of energy needed will be.

Okay, but back to the question, what will happen if you don’t eat before your weight lifting session? The main reason for weight training is muscle growth. Muscle growth is dictated by the overall balance of protein (muscle) synthesis[3] and protein degeneration making up for muscle protein balance. Training stimulates synthesis and degeneration at the same time.  Whether you have a positive or negative muscle balance during your work out is largely determined by the food that you eat before your session. Amino acids are parts of protein that serves as building blocks in our muscles. If one has a greater amount of these building blocks circulating around in the body going in to training, it will be easier for the muscle to pick them up[4]. If fasting, you will have a negative muscle balance during your training session since there are no building blocks for the muscles to take up. Additionally, hormone availability are important for muscle synthesis⁵. Since nutrition has shown to elevate hormonal levels during training, fasting result in decrease amount of hormones responsible for muscle synthesis.

Carbohydrates are stored in the muscles as glycogen and are used as the main fuel during resistance exercise[5]. The general belief is that if you don’t refill these stores, training will result in muscle breakdown which is the natural catabolic effect of fasting. Even if there are a lot of support behind this theory, some of it is subjective rather than objective [6]and performance have been shown to be maintained even when training fasted.

The difference in the chronic results seen in regards to fasted versus fed and resistance training responses could potentially be related to something referred to as anabolic super compensation[7]. Which means that the anabolic response might be stimulated and elevated when fasting, resulting in an even greater muscle synthesis post resistance training to make up for the lowered synthesis response during the training bout³. This is supported by studies not showing a different in results when food was ingested at different times but the total energy intake was matched for[8] [9]

Finally, the importance of a pre-work out meal is highly related to the type of exercise performed. Figure one ⁵ serves as a good guideline to whether you should eat before your work out or not. However, it doesn’t seem like there is a direct and significant benefit of performing resistance training fasted. So even if data shows that your body will be able to super compensate for what was lost during the session in a fasted state, spare yourself the potential demotivation and feelings of fatigue such as lack of energy and eat before your session rather than relying on your post-work out meal to satisfy your needs.

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[1] Ormsbee M. J, Thyfault P. J, Johnson A. E, Kraus M. R, Choi D. M, Hickner C. R. Fat metabolism and acute resistance exercise in trained men. J Appl Physiol 102(5), 2006.

[2] Warren A, Howden E J, Williams A D, Fell, J W, Johnson A N. Post exercise fat Oxidation: Effect of exercise Duration, Intensity, and Modality. Int J Sports Nutr Ex Metab 19: 607-623, 2009

[3] Kumar V, Atherton P, Smith K, Rennie J. M. Human muscle protein synthesis and breakdown during and after exercise. J Appl Physiol 106:2026-2039, 2009)

[4] Tipton K. D, Rasmussen B. B, Miller S. L, Wolf S. E, Owens-Stovall S. K, Petrini B. E, Wolfe R. R. Timing of amino acid-carbohydrate ingestion alters anabolic response of muscle to resistance exercise. Am J Physiol Endoctrinol Metab 281: 197-206, 2001.

[5] Helms R E, Aragon A A, Fitschen J P. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation.  J Int Soc Sports Nutr 11: 1-20, 2014.

[6] Zerguini Y, Kirkendall D, Junge A, Dvorak J. Impact of Ramadan on physical performance in professional soccer players. Br J Sports Med 41:398–400, 2007.

[7] Deldicque L, De Bock K, Maris M, Ramaekers M, Nielens H, Francaux M, Hespel P. Increased p70s6k phosphorylation during intake of a protein-carbohydrate drink following resistance exercise in fasted state. Eur J Appl Physiol 108:791-800, 2010.

[8] Trabelsi K, Stannard R S, Ghlissi Z, Maughan J R, Kallel C, Jamoussi, Zeghal M K, Hakim A. Effect of fed- versus fasted state resistance training during Ramadan on body composition and selected metabolic parameters in bodybuilders. J Int Soc Sports Nutr 10: 1-11, 2013.

[9] Tipton D. K, Tabatha A. E, Cree G. A, Aarsland A.A, Sanford P. A, Wolfe R. R. Stimulation of net muscle protein synthesis by whey protein ingestion before and after exercise. Am J Physiol Endocrinol Metab 8:71-76, 2007.