Winter is approaching. For many athletes, it is time for a change of scenery: leaving the roads behind and turning the mountains into a new playground. It is also an ideal period to build a base for April and beyond, after an end-of-season break that may have reduced fitness.
Body weight is one of the most important factors in running and cycling performance. In running, keeping weight under control can improve times by reducing relative effort and lower mechanical stress on the joints. Although body weight matters less in flat cycling events, its importance rises exponentially with the number and gradient of the climbs.
As Dr Asker Jeukendrup reported in Sports Medicine1 , (view the study) under the same fitness conditions, a 3 kg reduction in weight can produce a difference of up to 7 minutes over a 20 km event with a 12% gradient for novice athletes, and slightly more than 4 minutes for trained athletes. Keeping weight under control should therefore be a priority for triathletes, runners and cyclists, especially when preparing for hilly events such as mountain-bike races.
Weight loss requires energy intake from food to be lower than energy expenditure. This energy deficit causes the loss of both fat and muscle mass, often reducing performance. Preserving muscle mass is therefore critically important when following a calorie-restricted diet to lose weight.
Numerous studies have demonstrated the role of protein in maintaining muscle mass during periods of weight loss. One recent study in the American Journal of Clinical Nutrition2 (view the study) placed participants on a calorie-restricted plan for 4 weeks—a 40% reduction from estimated expenditure—and assigned them to two groups. One consumed the normally recommended amount of protein (1.2 g/kg per day), while the other consumed a higher amount (2.4 g/kg). Both groups performed high-intensity and strength exercise. Although both lost a substantial amount of fat, the loss was greater in the higher-protein group (4.8 and 3.5 kg, respectively). Most importantly, only the higher-protein group increased muscle mass (1.2 kg).
Figure 1. Changes in body mass (BM), lean body mass (LBM) and fat mass (FM) in the high-protein (PRO) and lower-protein (CON) diet groups. Both groups lost weight, but fat loss and muscle gain were greater in the PRO group.
In summary, these findings support maintaining a high-protein diet—2.0-2.5 g per kilogram of body weight per day, or around 25-35% of total daily calorie intake—during calorie restriction for weight loss. Lower body weight per se does not necessarily improve performance, because it may result from muscle loss. As athletes, the goal should be to reduce body fat while maintaining optimal muscle mass, with protein as a key ally. To achieve this,protein-rich foods such as meat and fish should be included in meals, prioritizing options with lower calorie density such as white meat including chicken and lean fish including hake or cod.
As an approximate example, a 70 kg athlete should consume around 140 g of protein during calorie restriction. This could include 100 grams of ham at breakfast—approximately 21 grams of protein per 100 grams—200 grams of chicken at lunch—30 grams per 100 grams—200 grams of hake at dinner—24 grams per 100 grams—250 ml of milk at breakfast and as a snack—32 grams per liter—and other protein-rich foods such as legumes or spinach. Protein supplements may also be useful when dietary intake alone makes it difficult to meet requirements, while helping limit energy intake. However, consult a specialist to individualize the nutrition plan.
REFERENCES
- 1. Jeukendrup AE, Martin J. Improving cycling performance: How should we spend our time and money. Sport Med. 2001;31(7):559-569. doi:10.2165/00007256-200131070-00009.2. Longland TM, Oikawa SY, Mitchell CJ, DeVries MC, Phillips SM. Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: A randomized trial. Am J Clin Nutr. 2016;103(3):738-746. doi:10.3945/ajcn.115.119339.
AUTHOR
Pedro Valenzuela
Researcher in the Physiology Unit at the University of Alcalá and the Performance Monitoring Unit at the Sports Medicine Center (AEPSAD, Madrid High Performance Center).
Website: www.fissac.com
