/**
 * Data Format Library
 * Centralized formatting functions for time, distance, pace, HR, and other fitness metrics
 */
/**
 * Converts speed from meters/second to minutes/km.
 * @param ms Speed in meters/second
 * @returns Pace in minutes/km (as a string "mm:ss")
 */
export declare function msToMinPerKm(ms: number | string): string;
/**
 * Converts distance from meters to kilometers or meters based on value.
 * @param meters Distance in meters
 * @returns Formatted distance string with unit
 */
export declare function mToKm(meters: number | string): string;
/**
 * Formats duration from seconds to various time formats.
 * @param seconds Duration in seconds
 * @param format Format type: 'hh:mm:ss', 'mm:ss', 'humanReadable'
 * @returns Formatted duration string
 */
export declare function formatDuration(seconds: number | string, format?: 'hh:mm:ss' | 'mm:ss' | 'humanReadable'): string;
/**
 * Formats heart rate value.
 * @param hr Heart rate value
 * @param includeUnit Whether to include 'bpm' unit
 * @returns Formatted heart rate string
 */
export declare function formatHeartRate(hr: number | string, includeUnit?: boolean): string;
/**
 * Calculates and formats heart rate zones based on max HR.
 * @param currentHR Current heart rate
 * @param maxHR Maximum heart rate (if not provided, uses 220 - age)
 * @param age User's age (used if maxHR not provided)
 * @returns Object with zone information
 */
export declare function getHeartRateZone(currentHR: number, maxHR?: number, age?: number): {
    zone: number;
    zoneName: string;
    percentage: number;
    description: string;
};
/**
 * Formats speed value to km/h or m/s.
 * @param metersPerSecond Speed in m/s
 * @param unit Output unit: 'kmh' or 'ms'
 * @returns Formatted speed string with unit
 */
export declare function formatSpeed(metersPerSecond: number | string, unit?: 'kmh' | 'ms'): string;
/**
 * Formats elevation/altitude values.
 * @param meters Elevation in meters
 * @param unit Output unit: 'm' or 'ft'
 * @returns Formatted elevation string with unit
 */
export declare function formatElevation(meters: number | string, unit?: 'm' | 'ft'): string;
/**
 * Formats power output (for cycling).
 * @param watts Power in watts
 * @param includeUnit Whether to include 'W' unit
 * @returns Formatted power string
 */
export declare function formatPower(watts: number | string, includeUnit?: boolean): string;
/**
 * Formats cadence (steps/min for running, rpm for cycling).
 * @param cadence Cadence value
 * @param type Activity type: 'running' or 'cycling'
 * @returns Formatted cadence string with appropriate unit
 */
export declare function formatCadence(cadence: number | string, type?: 'running' | 'cycling'): string;
/**
 * Formats temperature values.
 * @param celsius Temperature in Celsius
 * @param unit Output unit: 'C' or 'F'
 * @returns Formatted temperature string with unit
 */
export declare function formatTemperature(celsius: number | string, unit?: 'C' | 'F'): string;
/**
 * Formats date to various formats.
 * @param date Date string or Date object
 * @param format Format type: 'short', 'long', 'iso', 'relative'
 * @returns Formatted date string
 */
export declare function formatDate(date: string | Date, format?: 'short' | 'long' | 'iso' | 'relative'): string;
/**
 * Formats calories burned.
 * @param calories Calories value
 * @param includeUnit Whether to include 'cal' unit
 * @returns Formatted calories string
 */
export declare function formatCalories(calories: number | string, includeUnit?: boolean): string;
/**
 * Converts and formats pace between different units.
 * @param value Pace value
 * @param fromUnit Input unit: 'min/km', 'min/mi', 's/m'
 * @param toUnit Output unit: 'min/km', 'min/mi', 's/m'
 * @returns Formatted pace string
 */
export declare function convertPace(value: number, fromUnit: 'min/km' | 'min/mi' | 's/m', toUnit: 'min/km' | 'min/mi' | 's/m'): string;