Mini-Study: MTI’s Swim Progression Improves 500m Freestyle and Combat Sidestroke Times — Treading Protocol Needs Refinement

By Sam Johnson

BLUF (Bottom Line Up Front)

Swimming is a required skill for many military and tactical populations, yet standardized progression models for building swim performance and water confidence are limited.

Drawing from MTI’s success with interval-based improvements in running, this four-week mini-study explored whether similar progressions could enhance swimming endurance and comfort in the water.

Our aims were twofold:

1. Determine the effectiveness of MTI’s swimming programming for 500m swim times in both freestyle and the combat sidestroke.

2. Assess the feasibility and effectiveness of a progressive treading protocol as a general water confidence builder.

Participants

Four male interns participated in the study:

• Samuel – Freestyle stroke

• Jackson – Freestyle stroke

• Seung – Combat sidestroke

• Emmett – Combat sidestroke

All participants trained once per week, every Thursday in July, for a total of four swim sessions.

Swim Protocol

Each session included interval-based swim training tailored to either freestyle or combat sidestroke:

• Weeks 1–2: 150-meter intervals (e.g., 3x150m with 1–2 minutes rest)

• Weeks 3–4: 250-meter intervals (e.g., 3x250m with 2–3 minutes rest)

Baseline and Post-Test Assessment: Time to complete 11 continuous laps (~500m).

Swim Test Results

Three out of four participants improved their time. Jackson experienced a significant regression, likely due to cumulative fatigue or pacing mismanagement.

Treading Protocol

After swimming, participants performed a progressive treading sequence designed to improve comfort and competence in unstable aquatic conditions.

Each session consisted of 10 rounds of:

• 15s tread

• 15s no-hands tread

• 15s tread

• 15s tread holding a brick

Each week, the interval durations increased by 5 seconds, progressing from 15s in Week 1 to 30s in Week 4.

Participant Experience:

• Sam and Seung: Unable to complete even one full iteration of the progression. Instead, they attempted to tread water continuously for the same total duration.

• Jackson: Progressed through the full treading protocol as prescribed and showed steady improvement.

• Emmett: Completed all treading rounds, reflecting his swim competency.

Concurrent Training Factors

It’s important to note that this study was conducted alongside several other physically demanding studies within MTI’s July Geek Cycle, including:

• 60-lb ruck tests

• Sandbag get-up assessments

• Squatting and loaded mobility training 3x/week

• Climbing sessions and grip-intensive protocols

These concurrent stressors likely impacted swim recovery and performance, particularly for participants newer to aquatic training.

Discussion

Overall, this mini-study shows that interval-based swim training can effectively improve endurance for most athletes, even with low frequency (1x/week). Three of four participants improved their swim times — including one who was previously unable to complete the 500m test.

The drown-proofing progression proved valuable but overly ambitious for some. While Emmett succeeded in completing the entire progression, Jackson was the only other participant able to follow it consistently. Sam and Seung were unable to complete even one full round, highlighting the need for MTI to further refine our water confidence progressions.

Jackson’s regression in swim time — despite maintaining training frequency — reflects the unpredictable impact of cumulative fatigue. The demands of the broader Geek Cycle may have dulled his aerobic output, even as his technical confidence in the water improved.

Importantly, this study also confirmed that combat sidestroke, though less commonly emphasized in civilian swim training, can be effectively improved using structured interval work. We were specifically testing whether combat sidestroke swimmers could meet the demands of short, faster-paced intervals, and Emmett’s improvement confirms this is a viable progression method.

It’s also important to remember that swimming performance is heavily influenced by technique. Improvements in swim times may be partially or entirely due to increased technical efficiency, especially among novice swimmers. Structured, consistent exposure alone can improve stroke mechanics, breathing rhythm, and pacing without requiring large conditioning adaptations.

Conclusion

This study supports the feasibility of using interval-based progressions for both freestyle and combat sidestroke swimming. While not universally effective across all participants, these progressions yielded measurable improvements in performance and water confidence for most.

The treading protocol, while conceptually strong, was too advanced for less experienced swimmers and will require future scaling options. Despite that, it offers a promising framework for developing psychological and physical readiness in tactical aquatic environments.

Next Steps

• Refine the treading protocol to better accommodate inexperienced swimmers.

• Develop a treading assessment to establish baseline competency and appropriately scale progressions.

• Conduct a refined follow-up mini-study to test MTI’s swimming progressions and intervals at a higher frequency (e.g., 2–3 sessions per week). Increasing session volume will allow us to better evaluate training adaptations, assess progression pacing, and determine how swim performance improves under more focused aquatic programming.