USA Triathlon News Blogs Multisport Lab Mixing Up the System...

Mixing Up the Systems

By Aaron Scheidies | Dec. 11, 2017, 6:11 p.m. (ET)

swim backstroke

It’s important to train all of our metabolic systems within our training. This is why we do the long ride, the track sessions and the short rest intervals in the pool. Mixing up these systems within a training session is a way to make even larger gains, especially for the sprint and Olympic-distance triathlete. In these races, everything happens quicker and the time gap to make a move or react to others is much smaller and can be much costlier. This means that being able to switch between the different metabolic systems quickly and becoming very efficient at utilizing energy from each system without long transition gaps is crucial.

Below are sample workouts from each discipline that will train your metabolic systems to transition quicker. Do these workouts and you will be better prepared for your next sprint or Olympic-distance race.


200 yards, easy
3X50yd (25 scull/25yd long hard pull)
3X50yd (25yd fists/25yd long hard pull)
8X25yd (alternate 25 build/25yd sprint)

Main Set 1
3 times through
100yd (5 strokes hard/10 strokes easy entire 100) short rest interval (RI)
300yd sprint hard
45 seconds rest

Main Set 2
3 times through
200yd tempo short RI
50yd sprint
30sec rest

Main Set 3
3 times through
3X100yd tempo short RI
50yd ALL OUT
30sec rest

200yd easy backstroke every third


10 minutes easy spin
3X30sec high cadence (1100/105/110rpm/30sec normal spin between)
5X10sec hard/ 30sec easy spin
2min easy spin

Main Set 1: Aerobic/Tempo Intervals
3X5min (1min aerobic/2min tempo/2min aerobic)

Main Set 2
2 times through; 5-minute gradual build to tempo between the two rounds
8X (5sec stand hard/20sec sit hard/1min threshold
1min easy spin between each


10min jog
Dynamic stretching
2X (200 aerobic/200 tempo)
3X100m strides

Main Set 1
1200m tempo (base pace) w/ 10sec burst every 200m, 2min active recovery
2X800m tempo (base pace) w/ 10sec burst every 200m 1:30, act recovery

Main Set 2
5X (800m aerobic pace/400m VO2 pace) continuous

10min easy jog

Aaron Scheidies is a USA Triathlon Level 1 Certified Coach and licensed physical therapist. In his coaching with Team MPI, Scheidies has coached World Champion paratriathletes as well as IRONMAN World Championship qualifiers. Scheidies is an 11-time World Paratriathlon Champion and has set the world’s fastest time for anyone with a disability at both the Olympic (1:57:24) and IRONMAN 70.3 distances (4:09:54). He can be reached at

The views expressed in this article are the opinion of the author and not necessarily the practices of USA Triathlon. Before starting any new diet or exercise program, you should check with your physician and/or coach.