Research Article: Osteras H, Helgerud J, Hoff J. Maximal strength-training effects on force-velocity and force-power relationships explain increases in aerobic performance in humans. Eur J Appl Physiol. 2002 Dec;88(3):255-63.

Background: I cannot tell you how many people have come to me asking me about the importance strength training in their training program. I always explain to them that endurance performance is a function of three things:

• Aerobic Power (i.e. V_O2^max)
• Anaerobic threshold
• Exercise economy (or energy cost of the exercise), none of which are related to your strength.

With that in mind, I decided to look into this area and as it turns out some recent data suggests that in fact strength training may be an important adjunct to your training for endurance sport.

Introduction: Strength training leads to hypertrophy, which increases body mass. For most endurance athletes, this is not desirable as it increases body mass and translates into more work being required to move that body throughout the distance of the race. However, low repetition high velocity movements (ie. plyometrics) have been shown to improve strength with minimal increase in body mass, which may translate into improved power and subsequently increased performance.

Methods: Competitive cross country skiers completed 9 weeks of high intensity upper body strength training. The researchers measured muscular strength aerobic power, anaerobic threshold, and skiing economy. Resistance/strength training consisted of 3 sets of 5 repetitions at 85% of their 1 repetition maximum (the most they could left for one repetition) three times per week which took all of 15 minutes. Controls continued their normal training.

Athletes: 19 elite men and women cross country skiers divided into control and experimental groups. (Aerobic power = 61 mL/kg.min)

Results: Strength/power training improved skiing economy with no change in body mass, aerobic power, anaerobic threshold.

Discussion: Several studies have shown that resistance training improves endurance performance without any change in physiological variables that are known to correlate with endurance capacity. Data from competitive cyclists and runners suggests that time to exhaustion at a given exercise intensity can increase 11-85% when resistance training is included into their training programs. The researchers in this study showed that the improvements in performance may be a function of increased power production following high intensity resistance training. This falls in line with data that suggests that it is the highest workload you can achieve during a maximal test that is the best indicator of your performance, and not any physiological variables measured during that test (anaerobic threshold, aerobic power, running economy ect…) (See Jack Daniels or Veronique Billat and their V_O2^max data). The researchers speculate that high intensity resistance training improves neural adaptations and not increased muscle mass that allow the endurance athletes to perform at higher workloads during tests of endurance. Finally the researchers conclude that increased exercise economy associated with minimal amounts of high intensity strength training may translate into enhanced endurance performance.

Application: How do I apply this to my training? More importantly, if you are already doing 9-13 workouts a week, where do you get in the extra 3 strength training workouts? I like to think of resistance training as not merely lifting weights but applying a resistance to a muscle. So, how can I apply a resistance without lifting a weight? If you incorporate hills into your rides or runs, or include some explosive running or cycling bursts up hills or against a resistance, your body itself serves as the resistance to movements. More importantly, this is the type of strength training that may improve your performance as it is specific to your current fitness ability. So we recommend that you try to find runs/rides that have hills in them or try to find hills to use in your training where you can incorporate short high intensity bursts. Allow your body to completely recover in between each interval and do not feel as though this has to be the main component of your training. Think of this type of training like stretching or doing abs (i.e. they are the little things you do to ensure a well-balanced program).

IMPORTANT: This is only to be incorporated once you have developed a sufficient base of running or cycling mileage. Remember that the athletes in these studies are typically, well trained and have a lot of experience before they get started. Starting too early may lead to undue fatigue, stress and likely injury. However if you are ready for something new, high intensity strength training in this manner can serve as an important adjunct to your training that may give you that extra 30-40 seconds you need to get that last qualifying spot.