Eric Kramer, Asst Coach – Sprints/Hurdles, Grand Valley State University
Full video on Glazier Drive: Jumps for 400m in One Model
OVERVIEW
This is a coaching talk on the science of energy systems as applied to sprint and hurdle training. The coach explains that understanding energy systems matters because it shapes both how athletes train and how they recover, including why sleep affects hormone production (like HGH) and overall training benefit.
ATP AND THE BASICS OF MUSCLE ENERGY
The talk starts with the fundamentals: energy is the capacity to do work, and muscles run on adenosine triphosphate (ATP), stored directly in muscle cells. When the body needs energy, ATP breaks down into adenosine diphosphate (ADP) plus a phosphate molecule, releasing the energy that drives muscle contraction. The body then resynthesizes ATP by reattaching a phosphate to ADP, keeping the cycle going. Since muscles can only store a limited amount of ATP, it has to be continually replenished, which is why ATP alone only fuels about the first 30-40 meters of a race (roughly 4-6 seconds).
THE THREE ENERGY SYSTEMS
Track and field training draws on three systems: anaerobic alactic, anaerobic lactic, and aerobic. Anaerobic alactic is the dominant system in jumps, throws, and the very start of sprints. Anaerobic lactic covers events like the 4×100, 200m, 400m, and hurdle races. The aerobic system only really comes into play in races longer than 400 meters, which is why a sprints-focused program spends little time on aerobic training, though some distance-background athletes may add light aerobic work on their own.
ANAEROBIC ALACTIC SYSTEM
This system covers roughly the first 0-10 seconds of effort and doesn’t require oxygen, meaning an athlete could theoretically hold their breath through a 100m dash or a jump/throw, though it wouldn’t be efficient. Creatine phosphate (CP) is central here, helping store ATP and creatine in muscle tissue for use in competition; the coach mentions he doesn’t push creatine supplementation but won’t discourage athletes who ask about it.
ANAEROBIC LACTIC SYSTEM
This system extends out to about 40 seconds, the point where oxygen debt starts to set in. It explains why 100m/200m sprinters and short hurdlers can recover and race again within 20-30 minutes, while 400m runners hit a wall of pain near the final 100 meters as lactic acid builds up. This system still draws on ATP and CP but adds glycogen (stored in muscle and liver) as fuel. The coach notes a practical coaching implication: high school 300m hurdlers often struggle transitioning to the collegiate 400m hurdles because they’ve never trained past the 40-second mark, which is why he evaluates a recruit’s flat 400m time before committing to them as a 400 hurdler.
AEROBIC SYSTEM
This system kicks in around 70 seconds and powers events of 800 meters and beyond, using glycogen, fats, and proteins depending on duration, and requires oxygen throughout. The coach frames this as largely outside his sprint-focused program’s scope, more relevant to distance runners and longer endurance events like marathons.
KEY TAKEAWAYS FOR COACHES
The throughline is that recovery (sleep, hormone production) is tied directly to which energy system was trained, that race distance and event type dictate the dominant system at play, and that recruiting/training decisions, like vetting hurdlers for a 400m transition, should be informed by which system an athlete has actually trained.