A Christian Guide to Body Stewardship, Diet and Exercise

Chapter 5: Training for Endurance 103 From the above calculations, we see that she would need to lose a little over 20 lbs. in order to improve her VO2max score from 36 to 41 ml/kg/min. Again, this example assumed that her current level of fitness (numerator) remained the same. Additionally, losing weight may not always be the best approach to improving VO2max scores. For example, it would be contraindicated for individuals who already have a low percentage of body fat to lose weight, as the majority of weight lost would come from either water and/or fat free mass (muscle). Instead, it would be better for those individuals to perform regular speed and pace/tempo training in an effort to improve their level of fitness (numerator). In most cases, VO2max scores are improved by increasing one’s level of physical fitness (numerator) while simultaneously decreasing body weight (denominator). Recommendations for improving VO2max consist of performing high-intensity interval training 1-2 times per week (Haff & Triplett, 2016). Lactate threshold (LT) is the point in exercise at which lactate starts to accumulate in the blood above resting levels. Many researchers believe lactate threshold to be a better predictor of cardiovascular fitness than VO2max (Haff & Triplett, 2016). An individual’s LT defines the upper limit of a sustainable pace that can be maintained during training and/or competition. After blood lactate starts to accumulate above resting levels, it becomes impossible for the body to sustain that pace thereby resulting in fatigue. Running at paces below LT will allow the body to reach a steady state in which lactate production no longer increases and remains relatively stable. Ideally, athletes would be able to find and run at their maximal lactate steady state (MLSS) as this would allow them to run at the fastest possible pace without causing fatigue. Ironically, athletes with the same VO2max can have significant differences in their lactate threshold. For example, assume we have two athletes preparing for a 1-mile run and both have the same or similar VO2max scores. However, the LT for the first athlete occurs at 70% of their VO2max; whereas, the LT for the second athlete occurs at 60% of their VO2max. Because the first athlete is able to run at and sustain a pace at higher percentage of their VO2max, he/she will be able to run 1.0-mile faster than the second athlete. In untrained individuals, LT generally occurs around 60-70% of their VO2max. In well-trained endurance athletes, LT generally occurs around 75-80% of their VO2max. In elite endurance athletes, LT can occur at 90% or more of their VO2max (McCormick, n.d.). Recommendations for increasing LT include high-intensity interval training and/or interval training 1-2 times per week as well as pace / tempo training 1-2 times per week (Haff & Triplett, 2016). Exercise economy is the amount of energy required to maintain a consistent pace. Although not to the same extent as VO2max or LT, research suggests exercise economy to be another important factor in predicting endurance performance and may explain some of the performance differences between