diff --git a/VERSION b/VERSION
index 8adc70f..c18d72b 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.8.0
\ No newline at end of file
+0.8.1
\ No newline at end of file
diff --git a/config.lua b/config.lua
index 79486cc..17a8e0a 100755
--- a/config.lua
+++ b/config.lua
@@ -1,17 +1,17 @@
 -- World-specific configs are available. To create world-specific config,
 -- copy this file to `worlds/<worldname>/mod_minetest_wadsprint_config.lua`
 -- Common config values.
-minetest_wadsprint.HIDE_HUD_BARS                                         = false
-minetest_wadsprint.STAMINA_MAX_VALUE                                     = 100
-minetest_wadsprint.DYSPNEA_THRESHOLD_VALUE                               = 3
-minetest_wadsprint.SAVE_PLAYERS_STATS_TO_FILE                            = true
-minetest_wadsprint.PLAYERS_STATS_FILE_LIMIT_RECORDS                      = 1000
-minetest_wadsprint.PLAYER_STATS_UPDATE_PERIOD_SECONDS                    = 1
-minetest_wadsprint.PLAYER_CONTROLS_CHECK_PERIOD_SECONDS                  = 0.1
-minetest_wadsprint.SPRINT_SPEED_MODIFIER_COEFFICIENT                     = 3.8
-minetest_wadsprint.SPRINT_JUMP_HEIGHT_MODIFIER_COEFFICIENT               = 1.2
-minetest_wadsprint.SPRINT_STAMINA_DECREASE_PER_UPDATE_PERIOD_COEFFICIENT = 0.0005 -- 0.1 means 10% decrease
-minetest_wadsprint.SPRINT_STAMINA_INCREASE_PER_UPDATE_PERIOD_COEFFICIENT = 0.0001 -- 0.1 means 10% increase
+minetest_wadsprint.HIDE_HUD_BARS                               = false
+minetest_wadsprint.STAMINA_MAX_VALUE                           = 100
+minetest_wadsprint.DYSPNEA_THRESHOLD_VALUE                     = 3
+minetest_wadsprint.SAVE_PLAYERS_STATS_TO_FILE                  = true
+minetest_wadsprint.PLAYERS_STATS_FILE_LIMIT_RECORDS            = 1000
+minetest_wadsprint.PLAYER_STATS_UPDATE_PERIOD_SECONDS          = 1
+minetest_wadsprint.PLAYER_CONTROLS_CHECK_PERIOD_SECONDS        = 0.1
+minetest_wadsprint.SPRINT_SPEED_MODIFIER_COEFFICIENT           = 3.8
+minetest_wadsprint.SPRINT_JUMP_HEIGHT_MODIFIER_COEFFICIENT     = 1.2
+minetest_wadsprint.SPRINT_STAMINA_DECREASE_PER_SECOND_PERCENTS = 0.05 -- % decrease
+minetest_wadsprint.SPRINT_STAMINA_INCREASE_PER_SECOND_PERCENTS = 0.01 -- % increase
 -- Config values for `hudbars` mod (totally optional, applied only if installed).
 -- @see http://repo.or.cz/minetest_hudbars.git/blob_plain/HEAD:/API.md
 minetest_wadsprint.HUDBARS_IDENTIFIER                      = "sprint"
diff --git a/init.lua b/init.lua
index a4ee477..10b2115 100755
--- a/init.lua
+++ b/init.lua
@@ -35,6 +35,16 @@ else
   io.open(minetest_wadsprint.worldconfig,"w") -- Create empty world config (for user's convenience).
       :write("-- World-specific config. Copy here values from `mods/minetest_wadsprint/config.lua`:\n")
 end
+-- Calculating decrease and increase rates per period, based on that of seconds.
+minetest_wadsprint.SPRINT_STAMINA_DECREASE_PER_UPDATE_PERIOD_COEFFICIENT = (
+  minetest_wadsprint.PLAYER_STATS_UPDATE_PERIOD_SECONDS * 
+  ( minetest_wadsprint.SPRINT_STAMINA_DECREASE_PER_SECOND_PERCENTS / 100 )
+)
+minetest_wadsprint.SPRINT_STAMINA_INCREASE_PER_UPDATE_PERIOD_COEFFICIENT = (
+  minetest_wadsprint.PLAYER_STATS_UPDATE_PERIOD_SECONDS * 
+  ( minetest_wadsprint.SPRINT_STAMINA_INCREASE_PER_SECOND_PERCENTS / 100 )
+)
+-- Initializing HUD bars.
 dofile(minetest.get_modpath(minetest.get_current_modname()).."/init_hudbars.lua")
 ----------------------------------------------------------------------------------------------------
 ------------------------------------------------------------------------------------- api.stats() --
@@ -46,7 +56,7 @@ dofile(minetest.get_modpath(minetest.get_current_modname()).."/init_hudbars.lua"
 function minetest_wadsprint.api.stats(player_name)
     local player = minetest_wadsprint.stats[player_name]
     if player ~= nil then
-        return -- Return copy of values to be sure that they won't be changed directly by accident.
+        return -- Return copy of values to be sure that they won't be changed by accident.
             {
                 name = player_name,
                 stamina = player.stamina,
@@ -60,7 +70,7 @@ end
 ----------------------------------------------------------------------------------------------------
 ----------------------------------------------------------------------------------- api.stamina() --
 ----------------------------------------------------------------------------------------------------
--- Returns/sets player stamina.
+-- Gets/sets player stamina.
 --
 --  minetest_wadsprint.api.stamina(player_name)      -- Get player stamina percentage (1 is 100%).
 --  minetest_wadsprint.api.stamina(player_name, 0.1) -- SET stamina to 10% of STAMINA_MAX_VALUE.
diff --git a/util/version.png b/util/version.png
index f2b4109..96db4b9 100644
Binary files a/util/version.png and b/util/version.png differ