A question from my inbox: “In the past, when I swam butterfly I would push back through my hips and feel a powerful surge of momentum. Lately, I’ve been working on releasing my arms earlier. While my stroke counts are still about the same and I feel more relaxed, I no longer feel that momentum surge. Is this surge something I should look for or is it something that I should ignore, seeing as my stroke counts haven't changed?

If your stroke counts are similar and you feel more relaxed, I'd count that as a positive. Without seeing them, it’s hard to diagnose or compare your old form with your new, but sometimes those feelings of a momentum surge aren't necessarily signs of something to interpret positively. The feeling of applying lots of force to the water can be emotionally satisfying, but does have its potential costs.

A swimmer’s velocity will vary slightly within each stroke cycle as they gain or lose mechanical advantage or as their body position changes. For instance, in breaststroke, the leg recovery increases drag, while the leg thrust increases propulsion. The most economical way to swim is always to minimize variations from your average speed throughout the stroke cycle. Feeling a significant sense of momentum created at some point in a stroke may lead to quicker fatigue because it takes more work to overcome the inertia that may have occurred just before you felt the surge. While that sense of "Wow, I can really feel my power" may be satisfying, before long the extra power you are applying to overcome inertia can drain your fuel tank much more quickly than a style that feels less powerful.

There's far more tendency toward surge-and-deceleration in breaststroke and butterfly than in free and back because you stroke with both arms simultaneously–creating a surge–then recover with both at once–causing deceleration. If you’ve noticed that you can swim, say, 500 or 1,000 yards of free or back in good form, but can't do so in fly or breast, this is why. So there's a significant payoff for keeping your momentum as constant as possible in both short-axis strokes.

In fly, you do this by shifting from a sense of power to a sense of constant rhythm. Shift your focus from creating a sense of power in your arms and legs to maintaining a steady rhythm of chest-and-hips rocking. And because the fly recovery action has a higher energy cost than other strokes, there's also more opportunity to save energy on the recovery by making it more efficient. The energy you save can then be applied to maintaining your stroke length and initial pace for greater distances.

Four Ways to Save Energy on the Fly Recovery:

1. Hug the water. Don't fight gravity. Instead sweep your arms forward as close to the surface as you can.
2. Lead with your thumbs. As you sit reading this, try a fly recovery action with either arm, first with your thumb down, then with your palm down. You should feel more ease and less resistance with palm down.
3. Land wide. You start your stroke with your hands just outside your shoulders. So there's no point in finishing your recovery with your hands nearly touching in front of your head. Instead land a bit wider than your shoulders with palms turned slightly out. NOTE: If you’re used to landing in front of your head, landing even a bit wider than usual will probably feel as if it’s too wide. Keep practicing with that too-wide feeling.
4. Land softly. Channel your energy forward, not down, on landing. A simple way to do this is by minimizing noise and splash on your landing and thinking of landing softly. Ask a friend to tell you how high your splash is on landing. Six inches or less is great.

This article is excerpted from Extraordinary Swimming for Every Body. Also see our DVD BETTERfly for Every Body.